# The Reasons why Automatic Gearboxes Won't Work with EV's



## KiwiEV (Jul 26, 2007)

This is something I want to add to the Wiki as it's a very commonly asked question. There are a few scatterings of posts throughout the site with titbits of information on the subject but I was hoping that you lot could answer it again here, in simple short sentences.
God was that a run-on sentence or what.

So, as far as I've learnt, the two biggest drawbacks to using an automatic gearbox are:
1: The RPM range on auto gearboxes is set to work with the RPM range of an ICE engine. An auto gearbox would change gear too soon and too often for an electric motor to be efficient. 

2: The torque converter would require spinning even while the car is not moving to stop the fluid inside from "resting" at the bottom of the torque converter. This constant spinning wastes more amps.

Anyone think of reasons I've missed or am I way off track here?


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## rankhornjp (Nov 26, 2007)

Efficiency is also a factor in auto trannies, because the connection between the motor and transmission is made by the fluid in the torque converter the motor will always spin faster than the input of the transmission. Unless you have a lock-out converter, but they usually only lock at highway speeds.


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## KiwiEV (Jul 26, 2007)

Ahhhh of course, I forgot about that as well.
Good thinking Rankhornjp.


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## TheSGC (Nov 15, 2007)

I must be the crazy odd-ball out or something, but I am actually using an automatic transmission. Modern auto trannys (1996+ maybe even older) base the shifting on inputs from the engine RPM, temperature, oxygen sensors and whatever else, but they are all digital signals. I am building a microcontroller that mimics the original ICE, but does all the conversions and spits out useful working data. For instance, my Civic's auto tranny shifts at 2800-3000 RPM, so I would program the controller to shift when the motors hits its "shifting" time, say 5000 RPM, but the tranny will recieve a 2800 RPM signal, and then shift. The lock-out conveter is also electronically controller, and that will also be incorporated into the microcontroller, and activated when the vehicle is in motion.

As for the extra amp draw, while it is more than a stick, you can ofset that if you have a dual shaft motor, and the second shaft is connected to the power steering/brakes/AC, (which you really need on constantly for proper use) you would actually save juice compared to having second or third motors powering those accessories. At least thats my logic.


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## Coley (Jul 26, 2007)

Quote:
"2: The torque converter would require spinning even while the car is not moving to stop the fluid inside from "resting" at the bottom of the torque converter. This constant spinning wastes more amps.

Anyone think of reasons I've missed or am I way off track here?"

The convertor will stay filled with fluid, even when it is not spinning.
The spinning is needed, as the converter hub drives the main oil pump to keep the pressure ready for applying the clutches and bands when motion is required.

You could actually run an automatic without a converter if you had a pump, externally mounted, that could run up the trans pressure.
We used to run a Torque flight trans with a stick clutch. The clutch had a small hub that ran the front pump.

I don't know how long a lockup converter would run if used at slower speeds.
On my ICE truck I wired the L/C to come on in second gear, on a 700R4 overdrive trans.

It has worked well for 167,000 miles so far.

A stick trans, without a clutch, just works so well, why bother with the extra drag of an automatic??


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## david85 (Nov 12, 2007)

Coley, you might be onto something here. You are right about the pump, prahaps an electric powersteering pump could work to maintain fluid pressure when the transmission is not turning. I can't think of a reason why the lockup clutch would fail from being held in locked position, but not all transmissions are capable of locking in first gear, since the valve body is usually "hard wired" to disable lockup in 1st, though not all autos are the same.


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## rankhornjp (Nov 26, 2007)

Quote: "You could actually run an automatic without a converter if you had a pump, externally mounted, that could run up the trans pressure."

You really wouldn't need an external pump, the transmission has a front pump that provides the pressure. 

Quote2: " We used to run a Torque flight trans with a stick clutch. The clutch had a small hub that ran the front pump."

Thats the right idea. The purpose of the torque converter is to keep the engine from stalling out when you come to a stop.

This wont be a problem with an EV cause the motor comes to a stop when the car stops anyway. 

*LIGHTBULB!!*

On an EV if you could figure out how to make a hub that would prevent the transmission fluid from coming out of the front seal and also engage the input shaft and the front pump, you could eliminate the loss of the torque converter. Providing you with an auto trans that is as efficient as a manual (maybe, not sure about possible losses of the transmission clutches/bands) without the hassle of either retaining the clutch or leaning to shift all over.

Open to discussion/comment/correction.


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## houseoffubar (Nov 18, 2007)

This is of no help at all, because I can't remember where I saw it, I am sorry.
I saw an ev using an automatic transmission, the torque converter had been removed, and the owner said it works well, but no info on how he did it. I will try to find the car again, and post a link


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## Coley (Jul 26, 2007)

Running the front pump with the electric motor would work well, but might have a lag time on starting out, as there would be no pressure until the motor revved up.

No pressure either, to apply the low band, until a small amount of time passes, while the oil circuits transfer the pressure.

The combination of no and low pressure might just wear out the band sooner also. 

An Accumulator such as injection molding machines have, might solve part of this problem.

You would, however, have a "PARK" for holding on hills and that would be fine.


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## rankhornjp (Nov 26, 2007)

Coley said:


> Running the front pump with the electric motor would work well, but might have a lag time on starting out, as there would be no pressure until the motor revved up.
> 
> No pressure either, to apply the low band, until a small amount of time passes, while the oil circuits transfer the pressure.
> 
> ...


How bout something like this?:
http://64.202.180.37/files/accus.pdf

instead of allowing it to be automatic (cause you'd be at a light too long), you could install an electric valve inline. before you leave a light you could flip a switch to build up pressure in the tranny, and then when you drive down the road it would built back up (monitored with a gauge on the dash), then turn the switch off. not sure if you could somehow build a circuit to automate this, Im sure someone out there could.


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## Coley (Jul 26, 2007)

That was the working of an acumulator that I meant.

On turning the pump and the input shaft, you would need two different drives, as the input shaft runs slower than the pump, until the trans is in high gear.

Example:
You are at a stop sign, the input shaft isn't turning at all, but the pump is turning around 650 prm.
As you speed up, they both turn faster but still at a different rpm.

Another gear box would be needed in the bell housing area where the converter used to hide.....


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## piotrsko (Dec 9, 2007)

my $.02 being an EV newbie;

WAAAAAY back in the 80's we ran powerslide auto's and turbo-hydros with a nifty little adapter hub from some racing house flat circle track, took out the TC, installed hub on flywheel ring. push start the vehicle, obviously no clutch action. You could neutral slam it if you didn't mind burning out the bands. 

no other mods required or desired. powerslides come with every imaginable shift point available. Technology ought to have done the same for the new trannies.


your mileage will vary


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## Coley (Jul 26, 2007)

You must have been running early alums or cast irons so that you had a rear pump.
This adapter hub, did it just fit the input shaft only?

This wouldn't help an electric auto unless you had an aux oil pump....


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## Gashog (Dec 23, 2007)

Hey guys. Newbee here.
I've only seen two EVs up close.
One was built by Niagara Mohawk in upstate NY as a promo/PR vehicle. It had a TH200R4. It was gutted, jammed into second gear and there was no hydraulics at all. The gear shifter wasn't linked to the tranny but to the controller. L was regen mode, D was go and R was reverse.


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## piotrsko (Dec 9, 2007)

Coley said:


> You must have been running early alums or cast irons so that you had a rear pump.
> This adapter hub, did it just fit the input shaft only?
> 
> This wouldn't help an electric auto unless you had an aux oil pump....


ans: alum trannies. 

adapter hub just fit the input shaft like the TC it replaced and also powered the internal front pump so we had pressure to run the clutch packs and cooler and didn't need an external pump. some style adapters bolted directly to the crankshaft some used to require a flexplate. I'm pretty sure Ford still uses the TC to run a pump on the 4r100/(C6) but i'm not sure about the new front wheel drive stuff or the foriegn trannies except VW.


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## Coley (Jul 26, 2007)

Gashog said:


> Hey guys. Newbee here.
> I've only seen two EVs up close.
> One was built by Niagara Mohawk in upstate NY as a promo/PR vehicle. It had a TH200R4. It was gutted, jammed into second gear and there was no hydraulics at all. The gear shifter wasn't linked to the tranny but to the controller. L was regen mode, D was go and R was reverse.


There needs to be hydraulics to operate the bands and the clutchs.
They work on hydraulic pressure and can't lock up without it.
More info needed.......


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## Gashog (Dec 23, 2007)

Coley said:


> There needs to be hydraulics to operate the bands and the clutchs.
> They work on hydraulic pressure and can't lock up without it.
> More info needed.......


Weld that sucker!
If you want selectable gear ratios, you're SOL unless someone can figure out how to electro magnetically apply the packs and bands. With a glide, this might not be a big deal.


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## houseoffubar (Nov 18, 2007)

It seems to me,you would still have hydraulic pressure, as the removal of the converter, would require an adapter, which would spin the input shaft the same as before, it would just behave like the converter was locked all the time.
You would have no pressure at a stop, but as soon as you applied throttle, it would apply pressure, and away you go!
I don't know however, what is done with the fluid that normally goes to the converter. Is it re-routed?


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## Gashog (Dec 23, 2007)

houseoffubar said:


> It seems to me,you would still have hydraulic pressure, as the removal of the converter, would require an adapter, which would spin the input shaft the same as before, it would just behave like the converter was locked all the time.
> You would have no pressure at a stop, but as soon as you applied throttle, it would apply pressure, and away you go!
> I don't know however, what is done with the fluid that normally goes to the converter. Is it re-routed?


No. No hydraulics. No pump, no valve body. Just gear oil.


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## Mr. Sharkey (Jul 26, 2007)

And so what's the advantage? What you end up with is a non-shiftable, one-speed reduction gearbox. Why not just use a manual trans?


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## Coley (Jul 26, 2007)

Gashog said:


> Weld that sucker!
> If you want selectable gear ratios, you're SOL unless someone can figure out how to electro magnetically apply the packs and bands. With a glide, this might not be a big deal.


Why reinvent the automatic trans when a stick has it all.
A low band could be applied with a solenoid but the clutch would need hydraulic to go to 2nd gear.
Reverse would need 2 solenoids.
Not worth the effort, in my opine....


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## Gashog (Dec 23, 2007)

Coley said:


> Why reinvent the automatic trans when a stick has it all.
> A low band could be applied with a solenoid but the clutch would need hydraulic to go to 2nd gear.
> Reverse would need 2 solenoids.
> Not worth the effort, in my opine....


Weight?
I don't know if it would be worth it to try to get the apply devices to work electrically instead of hydraulically but getting one reduction would be really easy and you could gut the rest of it.


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## piotrsko (Dec 9, 2007)

NO NO No!!!!! OK; on a powerslide or turbo hydro OR a ford C4/C6, when you use the TC adapter {now read this carefully} 

the tranny functions fully just like normal, EXCEPT for the torque converter function. tranny fluid pumps all around, pressurizes everything: bands, selectors, shifting, out to the cooler and back, everything normal. NO CLUTCH ACTION because the tc isn't there. You can even push start the vehicle if you get the low band hold kit.
 
I'm not sure what happens when the motor isn't turning, as I didn't have that difficulty


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## Gashog (Dec 23, 2007)

piotrsko said:


> NO NO No!!!!! OK; on a powerslide or turbo hydro OR a ford C4/C6, when you use the TC adapter {now read this carefully}
> 
> the tranny functions fully just like normal, EXCEPT for the torque converter function. tranny fluid pumps all around, pressurizes everything: bands, selectors, shifting, out to the cooler and back, everything normal. NO CLUTCH ACTION because the tc isn't there. You can even push start the vehicle if you get the low band hold kit.
> 
> I'm not sure what happens when the motor isn't turning, as I didn't have that difficulty


Yeah we get it.
The Powerglide gets a spool. An then there's the "Clutchflyte" and the "Turboclutch" etc....with a clutch. 

I'm talking about gutting the tranny and using one carrier locked in one gear. Which is what NiMo did. Would I do it? I don't know...but it has been done.


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## Coley (Jul 26, 2007)

Quote:
"I'm talking about gutting the tranny and using one carrier locked in one gear. "

Not considered an "automatic" at this point.

You would still need to lube the carrier. Plus one gear is nothing compared to a stick shift.

No advantage that I can see.....

You would be better off with a Model T Ford and the 3 pedal system.......


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## Gashog (Dec 23, 2007)

Coley said:


> Quote:
> "I'm talking about gutting the tranny and using one carrier locked in one gear. "
> 
> Not considered an "automatic" at this point.
> ...


Lube with gear oil or something (synthetic 50 weight or whatever). 

NiMos' truck was a big dollar conversion. I drove it about 15 years ago and I can't find any info on it now but it was pretty slick and worked really well. Automatics are definitely lighter then manuals, especially if missing half the hard parts. That's the advantage I see. The few DIY conversions that I have read about use one gear most of the time anyway. It's just another option. Kinda like my trucks. All 4X4 and all have *low range*. I don't really _need _it but it's really nice to have (especially pushing a 7'6" plow with my Bronco).
I'm just playing devils advocate here. I don't have an EV and I've never built one. 
This thread is called "The Reasons why Automatic Gearboxes Won't Work with EV's".
I'm just telling you that at least one EV used an "auto" even if it was used as a reduction gear and a way to mount the motor only.
I'm also pretty sure that electric apply devices or even mechanical ones could be figured out but don't exist now. I'm not debating...just throwing it out there. Every one here likes the manual trans option. Cool. I'm not trying to talk you out of it. I'm just saying that you _could _use an auto gear box easily...if you didn't care if it shifted or not. It's more personal preference then technical impossibility.


Edit: I just thought of a way to shift an auto from outside. The snow plow on my Bronco reminded me of the old B model Macks with wing plows about 30 years ago. They didn't have PTO or central hydraulics. They had a hand pump. Two guys would ride around, one driving and the other guy pumping the hydraulics and controlling the plow. Just a thought!


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## Coley (Jul 26, 2007)

I don't mean to be debating either.

Its just that the topic was an "automatic transmission" which comes to mind as Not having to be reinvented for an electric vehicle.

Here is one for you.
Remember the riding lawn mower that had a large aluminum spinning disk run by the engine?

Depending on where you placed the rubber driven wheel on the disk, you got neutral, variable forward and variable reverse. 

Very simple, but a bear in damp weather.....


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## John (Sep 11, 2007)

Would a CVT suffer the same drawbacks as a regular auto?


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## Coley (Jul 26, 2007)

Good question.

I have never looked into them much. I mainly work on the powerglides, 350s and such.


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## Gashog (Dec 23, 2007)

They're still hydraulic and most are computer controlled. The old Subaru Justys' had an "analogue" CVT. I had another thought about the hydraulics. An auto with a spool would probably work fine with an electric motor. Put it in gear, press the accelerator, the motor starts to turn the pump dogs and the input shaft together, hydraulic pressure builds and engages whatever apply devices. Off you go, nice and smooth. It would shift automatically as per the valve body. You'd lose a lot of range due to the power sucking hydraulics but not as much as if you used a torque converter. That's where most of the heat and friction comes from.


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## Testit and u shall know (Jan 27, 2008)

Im no doubting Thomas. Where there is a way, there is a will. I believe that an auto trans can be converted with very little modification for an EV and work well through the entire gear change. Although not as economical as a manual, it is possible.
1st option is a manual-(cheap and simple to repair/replace parts), although an auto would be nice.


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## rankhornjp (Nov 26, 2007)

What about a manual valve body in an automatic, how would that work. A buddy of mine had one in his truck and it wouldn't shift unless you moved the shifter. Not sure how that would affect an electric motor, tho.


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## Bugzuki (Jan 15, 2008)

rankhornjp said:


> What about a manual valve body in an automatic, how would that work. A buddy of mine had one in his truck and it wouldn't shift unless you moved the shifter. Not sure how that would affect an electric motor, tho.


That system works the same internally, just requires you to move the shift valves. You would still need the hydrolic pressure to hold the gear.


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## Mastiff (Jan 11, 2008)

Personally, the Control of a manual transmission is preferable.
Not to mention they're easier to use in an EV conversion.

Plus, what the heck is that complicated about shifting?
1: Press Clutch
2: Shift Gears
3: Let go of Clutch


Plus I think a stick shift actually keeps you more alert while driving.

Now if you really didn't want to have to shift, just pick the right motor and go with a direct drive system, where the motor is attached directly to the differential, or a single speed gearbox.

You'll loose acceleration but you can cut the weight of the vehicle down, take up less space and not have to shift.


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## Bugzuki (Jan 15, 2008)

The best option would probably be to remove the torque converter (that is were most of the losses are). The torque converter has an external spline that spins the pump keeping the tranny in gear while stopped. Then the tranny input shaft sticks out of the tranny into the torque converter ingaging the internal mechanism.

So if you manufactured a pully to be run by a small motor - to continuously spin the pump. And, couple the motor shaft to the tranny input shaft. Then the drive motor would stop when the car stopped and there would still be pressure from the small motor. 

You would have to know what the best pressure would be for the tranny then find a small motor that could run at that speed and keep the pressure up for the least amount of power. If you really got fancy you could have the drive motor take over once it got up to speed. Then, shut off the pump motor.

This would obviously still use power that a manual would not use, but as time move on it will be harder and harder to find good manual transmission vehicles.


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## Gashog (Dec 23, 2007)

Bugzuki said:


> The best option would probably be to remove the torque converter (that is were most of the losses are). The torque converter has an external spline that spins the pump keeping the tranny in gear while stopped. Then the tranny input shaft sticks out of the tranny into the torque converter ingaging the internal mechanism.
> 
> So if you manufactured a pully to be run by a small motor - to continuously spin the pump. And, couple the motor shaft to the tranny input shaft. Then the drive motor would stop when the car stopped and there would still be pressure from the small motor.
> 
> ...


You're hearing me I think. The TC has three connections to the tranny. The pump is driven by dogs that fit into the snout. The stator is splined to the pump housing to keep it from spinning the wrong way. The input shaft is splined to the turbine. 

Driving the pump with the vehicle not in motion is like running the engine at a stop light. Not necessary. You could have the traction motor splined to the pump and the input shaft together. You want to go? Hit the accelerator, the motor turns the pump and the input shaft, the tranny engages and off you go.


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## rankhornjp (Nov 26, 2007)

Gashog said:


> You're hearing me I think. The TC has three connections to the tranny. The pump is driven by dogs that fit into the snout. The stator is splined to the pump housing to keep it from spinning the wrong way. The input shaft is splined to the turbine.
> 
> Driving the pump with the vehicle not in motion is like running the engine at a stop light. Not necessary. You could have the traction motor splined to the pump and the input shaft together. You want to go? Hit the accelerator, the motor turns the pump and the input shaft, the tranny engages and off you go.


 
My understanding of the TC is that the outer housing of the TC drives the pump and is connected to the crankshaft, so the pump turns at the same RPM as the motor all the time. However, the input is connect to the turbine, which spins at a slightly lower RPM, due to the fluid turning it, until the TC "locks out" if it has that option. How would having both of them turning the same RPM all the time affect the "pressure curve" of the pump? Considering that under normal operation, the pressure of the pump would always be slightly higher than the input RPM could provide.

Hope you understand the question.

James


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## Coley (Jul 26, 2007)

Quote:
"Plus, what the heck is that complicated about shifting?
1: Press Clutch
2: Shift Gears
3: Let go of Clutch

How bout this:
1: let up on the accel pedal
2: shift gears
3: move on down the road. ( no clutch to contend with) 

Simpler and saves the weight of the flywheel, clutch assembly and linkages.

If you drive the pump and input shaft the same. You will have a very poor start from a standing start because of lack of pump pressure.
This will also cause undo wear on the bands and clutches...


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## rankhornjp (Nov 26, 2007)

Coley said:


> Quote:
> If you drive the pump and input shaft the same. You will have a very poor start from a standing start because of lack of pump pressure.
> This will also cause undo wear on the bands and clutches...


My understanding of the way an auto works (and take that with a grain of salt), you dont need pump pressure in first gear, the pressure is used to change gears once you're moving. I have driven an auto with no fluid it in, and first gear works fine, it just wont shift (and the lack of fluid ruins the planetary gears).

james


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## Coley (Jul 26, 2007)

I have been working on automatics from GM. Ford, Chrysler and AMC and never saw one that would move without fluid. 

This is from 1960 until now.

Do you remember what the car was that you drove?


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## rankhornjp (Nov 26, 2007)

Coley said:


> I have been working on automatics from GM. Ford, Chrysler and AMC and never saw one that would move without fluid.
> 
> This is from 1960 until now.
> 
> Do you remember what the car was that you drove?


I have a ford f100 with a c-6 that had a cracked case and all the fluid leaked out, it was still able to move around the yard with it until i got a replacement.

James


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## Coley (Jul 26, 2007)

A crack in the case is one thing, no oil to the pump is another.

If you take all the fluid out of your trans, it will not move, no matter how hard you run the engine.

Same with no pump pressure. 

Until you rev the EV motor, pressure will come up slowly, but the low band will slip until the pressure builds up.

Hard to guess just when the band will fail......


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## Bugzuki (Jan 15, 2008)

Gashog said:


> You're hearing me I think. The TC has three connections to the tranny. The pump is driven by dogs that fit into the snout. The stator is splined to the pump housing to keep it from spinning the wrong way. The input shaft is splined to the turbine.
> 
> Driving the pump with the vehicle not in motion is like running the engine at a stop light. Not necessary. You could have the traction motor splined to the pump and the input shaft together. You want to go? Hit the accelerator, the motor turns the pump and the input shaft, the tranny engages and off you go.


That would work, but would cause serious hesitation at start up. The motor would be at high RPM when the clutches engage and would be like doing a Neutral dump in a gas engine. This is the reason I said that you would need to know what RPM the needed pressure was built up at and then find a small auxilary motor to drive the pump at that speed. The clutches need to stay engaged while you are stopped so that they are ready when you want to go.

If you wanted to get fancy you could have the main motor run the pump once it got up to speed and shut off the auxilary pump. That way you could save a little power (maybe).

You could also get an external pump and run the fluild in though the cooling lines. Then have the drive motor spin the internal pump. When internal pressure comes up turn off the external.



Coley said:


> Quote:
> "Plus, what the heck is that complicated about shifting?
> 1: Press Clutch
> 2: Shift Gears
> ...


Everyone knows that it is easy to shift gears. That is not the question here. The question was can an automatic work. If everyone wanted to shift manually nobody would have ever invented the automatic transmission. And the auto would not be taking over. As I stated earlier the reason this question is valid is because most cars on the road are automatics.


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## Sandy (Jan 22, 2008)

Say, since the orginal question was for reasons why NOT to use an automatic. I don't know if this would matter but you might check into it. An automatic takes Automatic Transmission Fluid, lots of it, is the ATF more toxic to produce or recycle then the heavy oil used in standards?

Here's another possible point, does the automatic require more resources to manufacture? If it uses more metal then that metal has to be forged... all the production costs can be considered part of the environmental problem, since it takes fuel to produce them.

Perhaps you will find that ATF is actually less of an enviornmental problem to get/produce/dispose then greese I don't know...

Then again what about clutch dust is that an environmental problem?


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## JPG (Feb 15, 2008)

http://www.poormansev.com

Is run by a fellow who runs a powerglide in his 64 Chevelle racecar EV. The Auto transmissions will pump up near immediately and will hold pressure at the starting line even with the motor stopped. He's running 13 second quarter miles so I don't really think the auto is making his car slow.

That said I still like sticks better  The problem is in racing it is easy to miss a shift/break parts while shifting a stick. 


JPG


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## Coley (Jul 26, 2007)

He is running a 2 speed, non automatic box. I did the same thing with a cast iron glide back in the early '60s at Cordova Drag Way.

The only real difference, between a stick and this modified box is the shift, that he is still making manually. 

It is just easier than a real stick, because it is hard to miss a shift when the heat is on. 

Still not an "automatic" transmission.....


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## little ghost (Feb 17, 2008)

What about using a CVT transmission? I really want to do this myself but not sure how it would react to high motor rpms?


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## Bugzuki (Jan 15, 2008)

The Honda CVT and I am sure most others still use fluid pressure to make things work so you would still need to produce pressure. It is also not like a gocart CVT where the belt slips to idle. the belt is a steel belt and it is always engaged. So there is some type of torque converter used. I did some work with a Honda CVT in 2003/4 but have forgotten the specifics.


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## little ghost (Feb 17, 2008)

Hmmm, i'd like to know how the pros did it... Rav 4 EV... Auto, EV1... Auto, i've even seen a suzuki swift ev with an auto on YouTube. Although the designer was a nutter and thought he'd invented a perpetual motion motor. The auto box did seem to work great though. He just popped it into D1 and off he went.


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## brian (Feb 29, 2008)

Coley said:


> A crack in the case is one thing, no oil to the pump is another.
> 
> If you take all the fluid out of your trans, it will not move, no matter how hard you run the engine.
> 
> ...


in our case where the converter has been removed from the equation the fluid is needed to move the vehicle. a conventional automatic with a converter needs the fluid to couple the motor with input shaft. 
a torque converter is a fluid coupling device that works by flinging the fluid against the vanes which then turns the input shaft and moves you forward.
if you just turn the shaft directly the gears etal.. will still move.

this thread has been helpful to me in the discussion of using an A/T on an EV which is something I have been contemplating for the past umpteen years.


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## Coley (Jul 26, 2007)

"if you just turn the shaft directly the gears etal.. will still move."

NOPE, nope and nope......not without fluid pressure to apply the low band....

All that you will turn is the shaft and the hub on the front clutch, but the car still won't move....


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## Sandy (Jan 22, 2008)

Say, I was also wondering, do the automatics provide "back" pressure to the engine, I'm asking because I wonder if you will be able to get regenerative braking with an automatic?


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## Bugzuki (Jan 15, 2008)

Usually the engine is connected to the torque converter, so there is only force there while you are at high enough speeds. Once you get to lower speeds the Torque converter turbine (forgot the proper name) is not spinning fast enough to make the housing turn. So, regenerative braking would not be very effective if you used the Torque converter.

But it you had a small motor running to produce the fluid pressure you would have perfect regen. The Clutches would stay engaged and the motor would be able to slow the car down. I am not sure exactly what would happen as the tranny downshifted, but I imagine it would be fine.

Like I said earlier the only way to use an automatic efficiently would be to have a small motor driving the fluid pump.


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## Coley (Jul 26, 2007)

I am also puzzled by the claim that an automatic is lighter than a stick trans??

Using a stick without the flywheel/clutch/clutch linkage/clutch pedal makes it very much lighter than most automatics.

To be a true auto, it should have the torque converter, as it does a job that most are ignoring.

A converter multiplies the torque of the driving unit (either ICE or EV) and gets you up and moving faster than a simple fluid coupling.

If you ever drove a Chrysler product from the '50s that used a fluid clutch AND a dry clutch, you would know just how bad they were.

The amps wasted to run an automatic box, even with an exterior pump, and try to get regen from it also, looks to be a bad outcome. Just my opine....


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## Bugzuki (Jan 15, 2008)

Coley said:


> I am also puzzled by the claim that an automatic is lighter than a stick trans??
> 
> Using a stick without the flywheel/clutch/clutch linkage/clutch pedal makes it very much lighter than most automatics.


I am pretty sure that most automatics are heavier then most manual transmissions. There is a lot more in the automatic. 



Coley said:


> To be a true auto, it should have the torque converter, as it does a job that most are ignoring.
> 
> A converter multiplies the torque of the driving unit (either ICE or EV) and gets you up and moving faster than a simple fluid coupling.
> 
> If you ever drove a Chrysler product from the '50s that used a fluid clutch AND a dry clutch, you would know just how bad they were.


I think the reason it is called an automatic is because it shifts automatically and not necessarily because it has a torque converter.

The reason I have not mentioned torque multiplication is because I do not think that an electric vehicle should have the torque converter. The only reason that you need a torque converter is because gas engines have abismal torque at low RPM. If you wanted good torque you would need to engage the transmission at higher RPM. And, of course, to allow the engine to keep running at a stop sign. 

With an electric motor both of these reason are handled by default. The motor stops turning when the car stops, and the electric motor has full torque at stall. 

I think it would be a really bad idea to run an automatic with the torque converter in place. There would be so much wasted energy at low RPM. Just my opinion (no hard data to back it up).



Coley said:


> The amps wasted to run an automatic box, even with an exterior pump, and try to get regen from it also, looks to be a bad outcome. Just my opine....


Yes, the automatic would be less effecient then a manual, but that was not the question of this thread. The question was would it work, and yes it would. Also as time moves forward it will be harder and harder to find a manual transmission car. So, I think this is a valid and important discussion.


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## TheSGC (Nov 15, 2007)

Bugzuki;27175
Yes said:


> When I was looking for a donor car, there wasn't a stick anywhere within 25 miles! Even when I went to buy a new car for college, Honda said that it would be 8 months before a stick made its way to my area. (Had to be special ordered, and I didn't have that amount of time to wait.)
> 
> As for the effieciency, I think people are over exagerating the losses. Taking the "Observed Data" from the Consumer Guide review of my 1996 Honda Civic donor, the manual got 33.8 MPG and the auto got 31.4. For the sake of argument, lets say the stick is 100% eff, then the auto would be 93% eff. That translates to only a mile or so less in range. Not a big deal in my books, and if you really care put a larger pack of batteries in.


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## Coley (Jul 26, 2007)

Just because an electric DC motor has full torque at the first turn, what is wrong with upping the torque with a converter??

The car would launch quicker and get up to speed using less amps....


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## TheSGC (Nov 15, 2007)

Coley said:


> Just because an electric DC motor has full torque at the first turn, what is wrong with upping the torque with a converter??
> 
> The car would launch quicker and get up to speed using less amps....


I am actually hoping it will do that in my auto conversion! Use as small amounts of amps as possible to increase range and not burn out the motor, but still have pep at low speeds.


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## demolay rules (Feb 28, 2008)

I get what you are saying with that 93% efficiency, but listening to the other people on this forum I think that the gas motor and transmission efficiency is calculated differently that electric. Just a thought.


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## Bugzuki (Jan 15, 2008)

In a gasoline engine an automatic has relatively the effecience, but the engine is always running in both cases. In an electric motor vehicle everytime you stop them motor should stop too.

If you use a torque converter you will need to keep the drive motor running all of the time. This is to keep the fluid pressure built up. If you stop the torque converter the pump will stop and the tranny will disengage. Then when you start the motor, the pressure would build engaging the tranny gear and away you go. But, the engagement would not be smooth and would cause excessive clutch wear. The transmission is designed to build pressure while in park or neutral not drive.

Also having the large drive motor spinning at 500 - 1000 rpm while stopped is not very efficient. It would be much better to have a small motor designed to run efficiently at the speed needed to maintain the fluid pressure.

I doubt you would launch any quicker by having a torque converter. Most IC automatics are not know for their faster launch then a manual. Most automatics also have higher final drive gear ratios then Manuals - due to only having 4 speeds instead of 5 or 6.


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## little ghost (Feb 17, 2008)

brian- did you mean to say in our case the torque convertor and fluid are NOT needed, or they are needed?

Alex


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## xrotaryguy (Jul 26, 2007)

He is saying that the traction motor needs to stay running at all times unless you want to run an external fluid pump. The electric fluid pump is probably the more efficient way to go. 

Retaining or ditching the torque converter is up to the builder. 

If you keep the torque converter, you will sacrifice some efficiency. however, some of that efficiency loss could be avoided by programming the transmission's control unit to unlock the torque converter only immediately before every shift, and relock the torque converter immediately after every shift. 

If you omit the torque converter, the drive-train will be a bit more efficient due to the absence of "slippage" between the transmission and the traction motor and due to the reduced rotating mass of the drive train. This could improve range, top speed and acceleration. However, the transmission will probably wear prematurely and the shifts will probably give the driver a an undesirable kick in the pants with every gear change. I suppose that the transmission could be programmed to engage the clutches more gradually, but that will furhther reduce the transmission's life expectancy.


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## demolay rules (Feb 28, 2008)

What I think is that you guys should stop sitting around like politicians and realize that what was mentioned at the beginning is the answer: just making the motor idle. Why make the subject more complicated with torque converters, fluid, etc. when the answer was there from the beginning!

Sorry about that rant but it was really bugging me.


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## Coley (Jul 26, 2007)

demolay rules said:


> What I think is that you guys should stop sitting around like politicians and realize that what was mentioned at the beginning is the answer: just making the motor idle. Why make the subject more complicated with torque converters, fluid, etc. when the answer was there from the beginning!
> 
> Sorry about that rant but it was really bugging me.


The original post was about using an automatic trans and converter as a complete unit, just as it would be used by an ICE.

The posts were to discuss that idea.

The motor could idle as low as 350 rpm and still give satifactory pressure for the trans to work as it did behind the ICE.

"Converters, fluid, etc." do not complicate anything, as they are needed to have a true "AUTOMATIC" transmission in an EV.

You either want one or you don't....it is up to the builder.....


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## ronis108 (Dec 14, 2007)

I have not read this entire thread, (it is 7 pages long you know) but I an wondering about my Prius. It is an automatic and the ICE cuts off when the car comes to a stop. What happens to the pressure in the automatic? 

While I'm bringing up the prius, has anyone converted one to total EV? I am thinking after my warrenty is up I might want to look into that.
ron


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## TheSGC (Nov 15, 2007)

ronis108 said:


> I have not read this entire thread, (it is 7 pages long you know) but I an wondering about my Prius. It is an automatic and the ICE cuts off when the car comes to a stop. What happens to the pressure in the automatic?
> 
> While I'm bringing up the prius, has anyone converted one to total EV? I am thinking after my warrenty is up I might want to look into that.
> ron


The Prius does not have an automatic transmission, it has a CVT transmission. In theory it should work better in an EV than a regular automatic, but I have not heard of anyone actually building a full EV out of a Prius, so I really don't know.


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## demolay rules (Feb 28, 2008)

What I meant by meantioning all those elements was not to say eliminate them from the EV, but from the discussion. It just seems to be the simplest way to do this, with the least modifications.

Does anyone know of anyone on www.evalbum.com that has made an automatic? That might be helpful.


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## TheSGC (Nov 15, 2007)

demolay rules said:


> What I meant by meantioning all those elements was not to say eliminate them from the EV, but from the discussion. It just seems to be the simplest way to do this, with the least modifications.
> 
> Does anyone know of anyone on www.evalbum.com that has made an automatic? That might be helpful.


 
There is actually a Toyota Echo on that site that is automatic, but I have not found a way to contact the owner/builder to figure out what was done. I am just going to leave the torque converter in to make it as simple as possible, and if it all hits the fan, plopping in a maunal tranny will not require a new adapter plate/coupler configuration. But the auto WILL work if I have anything to say about it!!


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## JRP3 (Mar 7, 2008)

If you do a search on the EValbum for "automatic transmission" there seem to be a bunch of them. Here are a few:
http://www.evalbum.com/177
http://www.evalbum.com/62
http://www.evalbum.com/63
http://www.evalbum.com/644


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## Bugzuki (Jan 15, 2008)

It should be pretty easy to make the drive motor idle. Just adjust the throttle pot to not shut off all of the way. Adjust it to work at about 500-700 rpm or something like that.


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## JRP3 (Mar 7, 2008)

Yeah I was thinking the same thing but it seemed too obvious


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## demolay rules (Feb 28, 2008)

But that would really work, cuz what if you wanted to coast? I am not sure how you would make it work, but it would be a little more complicated (I think)


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## JRP3 (Mar 7, 2008)

Not sure what you mean, gas cars with automatics coast.


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## demolay rules (Feb 28, 2008)

you're right, nvm


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## little ghost (Feb 17, 2008)

That idea works for me. Let it idle.


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## JRP3 (Mar 7, 2008)

Anyone know how the RAV4EV and EV1 handled their automatics?


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## little ghost (Feb 17, 2008)

That's what i'd love to know, but given their budgets, it could have been electronic or anything. I think we surmised the answer is to either junk the torgue convertor or make the motor idle? Makes me laugh that getting hold of a stick is no problem for me here in the UK, and yet i want an auto! Whereas most people here can't get hold of a stick for love nor money. Good luck chaps. The only other thing i can't get my head round is how an auto box will know when to change gear. In an ICE situation it only has to deal with 6 or 7 thousand rpm, whereas you get 12 or whatever in an electric motor. How would that work? Wouldn't you get the tranny changing up too early as it would constantly think the motor was past the redline already...


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## John (Sep 11, 2007)

I don't know about the RAV4EV but the EV1 had a single speed transmission with reversing furnished by electrically reversing the motor. The car was always in that one gear. It was powerfull enough not to need any more gears. It would be controlled like an automatic even though it wasn't one.


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## xrotaryguy (Jul 26, 2007)

I don't think that we need to simplify the discussion and only focus on one way of doing things. If that attitude were applied broadly enough, we wouldn't even have a DIY EV message board. One of the purposes of the board is to discuss different ideas, their merits and their drawbacks. 

Some of the posts seem to suggest that the torque converter is responsible for maintaining line pressure. To my knowledge, this is not the case. The transmission actually has a fluid pump. It is generally (if not always) in the front of the transmission somewhere behind the bell housing.

The torque converter can be removed, but doing so does require some sacrifices and perhaps some programming.

I guess the easiest thing to do is to keep the converter and set the traction motor up to stay running at 350+ rpm at all times. Then again, that could require some programming as well.


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## demolay rules (Feb 28, 2008)

Couldn't you just put a spring on the potbox keeping the motor running at all times? Or could you program it to do that or something?


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## KiwiEV (Jul 26, 2007)

demolay rules said:


> Couldn't you just put a spring on the potbox keeping the motor running at all times? Or could you program it to do that or something?


You might be onto something there. What about putting a little resistor inline with your potbox lead?


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## Bugzuki (Jan 15, 2008)

xrotaryguy said:


> I don't think that we need to simplify the discussion and only focus on one way of doing things. If that attitude were applied broadly enough, we wouldn't even have a DIY EV message board. One of the purposes of the board is to discuss different ideas, their merits and their drawbacks.
> 
> Some of the posts seem to suggest that the torque converter is responsible for maintaining line pressure. To my knowledge, this is not the case. The transmission actually has a fluid pump. It is generally (if not always) in the front of the transmission somewhere behind the bell housing.
> 
> ...


Technically the torque converter does control the transmission fluid pump. The engine is bolted to the housing of the torque converter. The engine then spins the TC housing. The housing is then coupled into the tranny pump. That's the collar that sticks up off the housing. In this picture you can see the flat areas that engage the pump.










Then this picture shows the inside of the pump and you can kind of see that the flats of the TC engage the inner gear.










What I did not think about is that the tranny fluid comes out of the tranny between the shafts. So, so celling mechanism out have to be used to keep the fluid in if the TC was removed.

Sometimes, I wish that these post boxes were bigger so you could see more of what you were typing.


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## SirisC (Feb 8, 2008)

I found this article: Electronic Transmission Controller
It is instructions to build an electronic switch to change between gears and to lock/unlock the torque converter. May be usefull when looking at other cars.


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## little ghost (Feb 17, 2008)

I'm afraid I still don't understand how the auto box would work with a high reving motor, as the auto box decides on which ratio to use based on engine speed and throttle position. Right? If you put your foot down to the floor in an auto, it knows to change gear at the redline, at say 6 or 7000 rpm. With an electric motor you'll never see 10,000 rpm because the box will change too early. Or is the changing mechanism based on torque? In which case it will work like this: you will go to move from a standstill and the box will imediately change through 1-2-3-4 in the first 5 feet of driving because of all the torque being instantly available from an electric motor. Someone please try to explain!


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## Bugzuki (Jan 15, 2008)

That is a pretty cool idea. Then you could shift at 8000 rpm if the fluid pressure is not too high. You would have to check with the individual transmission.


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## demolay rules (Feb 28, 2008)

First of all, I think most change gears by RPM speed. I have heard of people hacking into their car's computer, but not for this reason. Does someone have a way to change the tranny computer so it shifts at EV redline?


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## xrotaryguy (Jul 26, 2007)

Automatic transmissions shift based on torque, rpm, and throttle position. Older transmissions would use a vacuum line and a modulator valve (GM) to indicate throttle position. I think that torque was basically inferred in this way too, so technically GM's old 350, 400 and 700R transmissions only used rpm and throttle position. Ford used a mechanical linkage (kick down linkage) to tell the transmission where the throttle was. 

Modern transmissions are all electronic and use more parameters. As such, the transmission could be programmed to shift anywhere you want... if you can "speak its language." If you really wanted a transmission to shift at 6 grand all the time, you could definitely do that. Line pressure might be a bit high. Energy loss related to spinning the fluid pump at unnecessarily high speed would be a down side too. This is yet another problem that could be overcome with an external fluid pump.

Thanks for the posts about the fluid pump and torque converter. For some reason, I never realized that the outer portion of the torque converter was the part that turned the pump. It makes perfect sense now. 

A person could still get rid of the torque converter. He could either use an external pump or machine a sleeve to run the pump while the input shaft is not turning. I guess the easy way to do that would be to cut off the portion of the torque converter that turns the pump and drive it with a small electric motor. 

Actually, I really like that idea  Again, thanks for posting the bit about the interface between the TC and the fluid pump. You kick ass! 

So, a person could run the traction motor to the automatic transmission's input shaft via a solid coupler. When the car is stopped, the traction motor is also stopped. Excellent. While the traction motor is stopped, the small pump motor would be turning the transmission's pump. Alternately, circuitry controlling the pump motor could tell the pump motor to turn off when the car is at a stop with the brake applied. This would mean that the traction motor would need to be disabled under this condition. 

As I have mentioned earlier, the lack of a torque converter would mean harder shifts. The shifts could be made softer by allowing the clutch packs to engage more slowly, but that would very likely lead to shortened transmission life. To get soft shifts without diminishing transmission life, the transmission's control module could be designed to communicate with the traction motor's control module so that the traction motor would provide a lesser amount of torque during shifts. This wold smooth out shifts and extend transmission life at the same time.


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## Bugzuki (Jan 15, 2008)

Sweet someone finally sees what I was trying to say all along about the small pump motor. It would be more work to begin with but I think a much better solution then the TC spinning all the time. Then you could have the fluid pressure constant all the time and would not have to worry about extra high pressure at 10000 rpm.

About the manual switch mechanism. The beauty of that system is that it by passes the computer when engaged. So, it would not matter what the computer was telling the transmission. The Tranny would only do what yosaid. The tranny computer is not inside the tranny only switches, solinoids(spellingz) and valves are in there.

This would be kind of a fun project, but I bought a manual Scion tC for my first personal conversion. My only automatic is the Aerostar, and I need that for trips and haulling stuff.


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## ngrimm (Oct 19, 2007)

You could use the neutral safety switch to turn the electric pump motor off or to turn the idling drive motor off if you were using the torque converter. That way when you pulled up to a stop you would have the option of putting it in neutral or park if you don't want to waste power. When you put it back in gear that would start the pump and give it a chance to build pressure before you hit the throttle. BTW some of the older gm auto trans have a governor inside them that causes them to shift but the vacuum modulator controls shift pressure well as lowering the shift points. The Mopar transmissions were neat since the kickdown linkage totally controlled the shifts and the pressure. Norm


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## xrotaryguy (Jul 26, 2007)

Bugzuki said:


> Sweet someone finally sees what I was trying to say all along about the small pump motor.


Did it take me that long?


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## JRP3 (Mar 7, 2008)

I don't know if this has been mentioned before but you might be able to use a pressure accumulator tank to hold pressure in the trans when not moving.


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## xrotaryguy (Jul 26, 2007)

JRP3 said:


> I don't know if this has been mentioned before but you might be able to use a pressure accumulator tank to hold pressure in the trans when not moving.


Oooooo another great way to go. The accumulator system could be set up to stop supplying fluid when the traction motor was stopped. Then, when the traction restarts, the accumulator could supply a sufficient amount of fluid and pressure to get the transmission operating properly in a very short amount of time; perhaps significantly less than one second. This would ensure that the accumulator would not run out of fluid if the car was at rest for an extended period of time like when it is parked over night, or even at a long traffic light.


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## demolay rules (Feb 28, 2008)

Hate to revive this thread, but I must know something: we've established that idling the motor is possible, but how would it be done? Would you need some kind of chip? Or would it be easier than that?


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## TheSGC (Nov 15, 2007)

Revive threads is good!!

Anyways, having the controller designed to idle the motor is the best way- but there is another!

All you have to do is find the right RPM needed for idling (step on the pedal until the RPMs are where you want it) and then measure the ohms at that level. Then place a resistor of that ohm ratings in series with the Potentiometer and you're done!

Tomorrow I am going to pick up an Automatic transmission that is identical to the one in my soon-to-be EV and design up the adapter/motor system.


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## JRP3 (Mar 7, 2008)

demolay rules said:


> Hate to revive this thread, but I must know something: we've established that idling the motor is possible, but how would it be done? Would you need some kind of chip? Or would it be easier than that?


This was covered:
http://www.diyelectriccar.com/forums/showpost.php?p=28313&postcount=70
It's basically the same way an ICE carb throttle works, adjust the throw on the pot so the lowest speed is the idle you need. Very simple.


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## demolay rules (Feb 28, 2008)

But wouldn't high pedal lockout not allow you to do this?


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## Coley (Jul 26, 2007)

There is another way to do it.

Take an old idling solenoid from a carburetor and put on your pot.
You could have a micro switch on the gearshift that would let the solenoid engage like at a stop sign.
To shut the car down just turn the solenoid off, by using the feed for it from the ignition switch, as an ICE would.

Cheap and easy.


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## demolay rules (Feb 28, 2008)

instead of measuring ohms across the circuit try this.

RPM's needed/total possible RPMs=x ohms/5k ohms. Then just cross multiply, right?

at 800 RPM revving speed and 6000 max RPM for the motor, that comes out at 666.66 ohms for the resistor. Would this work?

http://cgi.ebay.com/700-Ohm-10-Watt...ZWD1VQQ_trksidZp1638.m118.l1247QQcmdZViewItem


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## JRP3 (Mar 7, 2008)

demolay rules said:


> But wouldn't high pedal lockout not allow you to do this?


Depends on if/how you use that feature I guess. With an automatic high pedal lockout isn't as much of an issue, and you don't have to wire the contactor to shut off on high pedal. I've always felt that was overkill anyway.


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## TheSGC (Nov 15, 2007)

demolay rules said:


> instead of measuring ohms across the circuit try this.
> 
> RPM's needed/total possible RPMs=x ohms/5k ohms. Then just cross multiply, right?
> 
> ...


 
That should work. I have yet to try this myself, but I will be doing the full automatic conversion starting is 6 weeks, when the semester is over. I just picked up an auto tranny and torque converter, so I am going to clean it up and play with it.


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## ww321q (Mar 28, 2008)

I was just thinking (yea right!) if you still had the ICE motor in the car you could bypass the neutral safety switch and do some tests starting the motor in gear . You could see how long it was till it engaged in gear ...J.W.


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## demolay rules (Feb 28, 2008)

TheSGC,
When you start your conversion, please share with us your experiences with the auto tranny and which method you use.


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## TheSGC (Nov 15, 2007)

demolay rules said:


> TheSGC,
> When you start your conversion, please share with us your experiences with the auto tranny and which method you use.


Actually tonight and tomorrow I will be taking a look at the transmission and figuring it all out. I am draining the ATF and cleaning it up right now. I can tell you right now that I will most likely be using the torque converter because the spline shaft on the transmission is actually 3 different shafts in one, and ATF fluid flows through the shaft into the torque converter, which also acts as a pressure regulator (somehow). So a direct "torque-converter-less" adapter doesn't seem to be plausible as of this minute, on this tranny.

I will be posting pictures on my site tomorrow and a video of my controller in action. http://civicity.blogspot.com


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## captndiet (Apr 3, 2008)

New guy here.

Did not read all of this post but, depending on what auto transmission is being used there are commonly available drives that replace the torque converter and drive the pump and input shaft. 

http://www.speedwaymotors.com/p/5440,38_Powerglide-Drive-Flange-Sleeve-Bolts.html

Circle track racing and some racing boats use them.

Jeff


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## jlsawell (Apr 4, 2008)

Newbie here also , just learning as much as I can while paying off debt before I start converting my 1989 Nissan Pulsar. It's an auto, hence my interest in the topic.

My commute to work is 20km each way and the shops are about 7 km away, mostly flat commuting, HOWEVER: I want to know about reversing an Auto with the gearbox "disabled" by removing the TC and sensors etc:

I'm thinking about the following process:

Put shifter in R gear.
Start car.
Reverse out of driveway.
Turn engine off.
Put shifter in 2nd Gear
Start car.
Drive away.

I know it's not perfect and may be a bit of a hassle, but nowhere near the hassle of selling the auto, buying a new manual car, converting it and then having my wife complain that she can't drive it because she can't drive a manual...believe me - it's an issue weighing heavily on me!

By manually "locking" the auto in a suitable gear, will I still be able to drive around, despite it not being a perfect solution?

Or should I bite the bullet and buy a manual with a blown ICE to convert?

Second question:

What about charging the EV at work? I'm parked out the front of the office in direct sunlight, but with no electricity available. Is it feasible to put a solar panel between the windscreen and the foil shade I use to trickle charge the batteries while I'm at work?


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## TheSGC (Nov 15, 2007)

You're idea may not work. Later today I am going to start a new thread on the auto transmission in my civic and what I have to do with it and with pictures and stuff.

But here is why your idea wont work with my transmission: The transmission will not engage when started in gear. The transmission computer would see it as a stall, and disengage the gear. In order to use the auto, it must be spinning and have started up in Park or Neutral. If at anytime the motor shuts off when the transmission is in Drive or Reverse, then the transmission computer will not engage into any gear until the transmission has been put into Park or Neutral, then shut off and started off again. Hence the need to idle the motor.


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## JRP3 (Mar 7, 2008)

jlsawell said:


> Second question:
> 
> What about charging the EV at work? I'm parked out the front of the office in direct sunlight, but with no electricity available. Is it feasible to put a solar panel between the windscreen and the foil shade I use to trickle charge the batteries while I'm at work?


No where near enough surface area to make a difference.


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## b.koen (Mar 9, 2008)

Srg

very useful info on the last post, this was what i was wondering concerning the tranny computer. i.e safety and such


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## ngrimm (Oct 19, 2007)

Since you mentioned safety one thing I was thinking about was the auto transmission fluid. Granted I have two cars with auto trans but locally in the last year we have had two fatal accidents where cars crashed into trees and burst into flames before any of the occupants were able to escape. Two adults and three small children just last week. Now they say the gas tank ruptured but I think there is just as much chance the fire was started by atf being sprayed on the hot exhaust. The reason I think that is because my brother owned several tow trucks for many years and most of the fires he encountered were caused from that. Also I saw a demonstration at an environmental safety class where they had two pans on a hot stove with one containing gasoline and the other atf. The gasoline evaporated and the atf burst into flames just from the heat. Not saying what anyone should do, just an observation. Norm


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## TheSGC (Nov 15, 2007)

ngrimm said:


> Since you mentioned safety one thing I was thinking about was the auto transmission fluid. Granted I have two cars with auto trans but locally in the last year we have had two fatal accidents where cars crashed into trees and burst into flames before any of the occupants were able to escape. Two adults and three small children just last week. Now they say the gas tank ruptured but I think there is just as much chance the fire was started by atf being sprayed on the hot exhaust. The reason I think that is because my brother owned several tow trucks for many years and most of the fires he encountered were caused from that. Also I saw a demonstration at an environmental safety class where they had two pans on a hot stove with one containing gasoline and the other atf. The gasoline evaporated and the atf burst into flames just from the heat. Not saying what anyone should do, just an observation. Norm


Ahh yes, but you are forgetting that there will be no more catalytic or engine to get hot and catch stuff on fire.


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## Coley (Jul 26, 2007)

Quote:
"ATF fluid flows through the shaft into the torque converter, which also acts as a pressure regulator".

Probably what you have is a lock-up converter trans. The fluid is going to the clutch. No pressure regulation in the converter.

If you "lock" a trans in one gear.....it is not an automatic anymore......

The best bet is to idle the motor (200 rpm or so) to keep the automatic running as designed. The lock-up would be a good thing in high gear.


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## jlsawell (Apr 4, 2008)

I may not have been clear enough with my description of the auto gearbox: I don't intend the let the engine computer sense that the car is in gear. I'm planning to bypass/remove this feature with the ICE computer.

In the same way that I don't need it to measure fuel flow, O2 or injector status - can I tell the electric motor to start with the auto in gear, and slowly increase the electrons until we start moving?

I don't need the auto to change gear while moving - I'm not doing any freeway driving and rarely driving more than 70km/h. If I start it in second gear, I'll just leave it in second until I get to work.


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## TheSGC (Nov 15, 2007)

I am not sure if you can even run the auto tranny without the transmission computer. If anything, it would go into "limp" mode and operate in one direction at a very low speed, and be uterly useless. 

Also, I think you have to have the motor idling before you can put it into any gear. Once the motor stops spinning, the transmission loses pressure and then loses its gear again. This transmission also uses an electronic interface to change the gears. There is no shift linkage from my shifter to my transmission, just electrical wires.

I have been playing with my extra transmission I got, and since it there is no computer on it right now, or motor, if I spin the shaft, it takes a while for it to build some pressure, and then it starts spinning the drive shaft at what looks like 2nd gear. Your car manual should tell you what would happen to your transmission if it went into "limp" mode.


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## Al.S (Apr 5, 2008)

I'm new to electric vehicles and have very little experience with them,been thinking about building one using the diesel-electric train idea.

I've given some thought to using an automatic transmission.The transmission I would use would be a 4L60,for several reasons.Number one is,the 4L60's pressure is controlled by a throttle valve and uses a cable to accomplish this,it is not done in or with the TC.The 4L60E is controlled electronically through an EPC solenoid,the transmission is completely electronically controlled hence the E.The 4L60 only requires 12v for the lock-up solenoid.

Any automatic trans will require a TC,or as mentioned a remote pump.Without a TC it would need a remote pump that would come on and stay on when the drive motor is stopped,this would keep the trans engaged in the chosen starting ratio.Without a TC or a remote pump,the trans will not stay engaged at a stop.Once the drive motor started moving oil in the pump again,the remote will turn off.A custom built hub would be made to drive the pump and the input (turbine) shaft.This would also be a direct link to the motor,thus taking the place of the lock-up clutch.

A TC could be custom built for use with an electric motor and no remote pump.I havn't done any figures,but I'm guessing the stall speed at the turbine would have to be between 6 and 8 hundred rpms,the lower the stall number,the more efficient the energy is transferred to the input shaft.The drive motor will have to idle @ around 550 rpms to keep the pump moving enough oil for the pressure regulator valve.A TC for this application could be built for an 8inch housing and trimmed inside.The dampener spring assy could be removed and eliminate the sprag.With a smaller diameter and weight trimmed,starting energy would better transferred and reciprocating weight would be drastically reduced.

Without a remote pump or a TC an automatic will not have enough intial pressure to take off properly with a drive hub and will fry clutches,quickly. 

Automatic transmissions will not move if oil cannot be pumped through them. 
One clutch pack could be pinned,use a drive hub,but automatics need oil pumped through lube veins,cetrifigal force works against splash oiling.It wouldn't live long like this.

Automatic shift timing can be custom adjusted at the shift valve and governor springs.The speed of the shifts can be adjusted to be made compatable with the drive motor and final drive ratio,part of the reason for removing the dampener springs in the TC.

Subaroooooo Justy uses a powder TC,it has metal powder inside and uses 12v to regulate the turbine speed,not oil.

An UN-Automatic circle track transmission will not work for this application.The UN-Automatic's pump is controled at the drivers seat with a ball valve,it's on or off.

There are coast clutches or a coast band (depends on the trans style) used for ICE braking,therefore,regenerative braking will work with an automatic trans.

TC's and planetarys are the heat makers in an automatic.A cooler will have to be used,at least a 19,000 btu unit,an aluminum auxillary cooler,by itself,will not cool an automatic trans properly.


Soon as I think of some more ideas,I'll post up.In the mean time I'm gonna surf the site and learn.


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## TheSGC (Nov 15, 2007)

diamondgoldsilver said:


> I must be the crazy odd-ball out or something, but I am actually using an automatic transmission.


YES!! That makes two of us!! 

I am designing my adapter plate system right now and hope to have it qouted this week. What car are you using for your conversion?


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## Coley (Jul 26, 2007)

diamondgoldsilver said:


> I must be the crazy odd-ball out or something, but I am actually using an automatic transmission.


What transmission and what hook up?


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## aeroscott (Jan 5, 2008)

Al.S said:


> I'm new to electric vehicles and have very little experience with them,been thinking about building one using the diesel-electric train idea.
> 
> I've given some thought to using an automatic transmission.The transmission I would use would be a 4L60,for several reasons.Number one is,the 4L60's pressure is controlled by a throttle valve and uses a cable to accomplish this,it is not done in or with the TC.The 4L60E is controlled electronically through an EPC solenoid,the transmission is completely electronically controlled hence the E.The 4L60 only requires 12v for the lock-up solenoid.
> 
> ...


 if you needed 19000 btu that's 19000 / 3.4 =5588 watts , I hope its not that high of a loss .


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## KiwiEV (Jul 26, 2007)

diamondgoldsilver said:


> I must be the crazy odd-ball out or something, but I am actually using an automatic transmission.


This is interesting, keep us all posted on how you get on (you too SGC). I know another guy who's taking a leap and using an auto gearbox too. My hats go off to those brave few willing to take the plunge. (I'm not one of them!)


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## TheSGC (Nov 15, 2007)

KiwiEV said:


> This is interesting, keep us all posted on how you get on (you too SGC). I know another guy who's taking a leap and using an auto gearbox too. My hats go off to those brave few willing to take the plunge. (I'm not one of them!)


I am in the process of writing an article on how I am doing it and will post it when I am done. I am even going to include pictures! This week I am going to have the coupling parts quoted at a few companies, but my dad is bringing the designs and flex plate to his work and give it to the machinist and see what they think and if they can do it for free!! 

My EV car project actually got a code name from his work so he can order free samples and talk about it like any other company project, so there is a lot of hope for a free coupling system. Apparantly there are so many projects with crazy code names that no one knows what they are, they just do what they are told because there are designs in front of them and not too many questions are asked. So far I have gotten a few copper busses and large heatsinks.


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## TheSGC (Nov 15, 2007)

Ok, I just posted a link to my article in the Wiki. 

http://www.diyelectriccar.com/forums/showthread.php?t=11625

Give it a read and tell me what ya think!


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## b.koen (Mar 9, 2008)

super...

Can't wait to read the results! I truly admire and applaud your effort.

Brian


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## Coley (Jul 26, 2007)

You are on the right track.

You can experiment with idle speed, by checking front pump pressure with a gauge, to see how low the idle can be set and still run the trans.

My guess would be 2/300 rpm. The 700 figure was to keep the ICE running comfortably at stops.

You can also change the governor springs to get more desired shift points.

The lockup converter can be run with a switch, to turn it on/off whenever you want it.

I wouldn't worry about heat buildup, so a small aluminum aftermarket cooler would do fine. A lot of engine heat transfers to the automatic in an ICE car.


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## jlsawell (Apr 4, 2008)

TheSGC said:


> Ok, I just posted a link to my article in the Wiki.
> 
> http://www.diyelectriccar.com/forums/showthread.php?t=11625
> 
> Give it a read and tell me what ya think!


This is precisely what I was visualising for my Pulsar N13. Thanks TheSGC!

Quick question - is your civic front-wheel-drive with a transaxle or is it rear-wheel drive? The pictures in your article look like a standard auto gearbox for rear wheel drive.

I don't think there will be any difference using this setup between the two, but since the Pulsar is an auto + transaxle front wheel drive I'd like to find out as much as I can.


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## TheSGC (Nov 15, 2007)

It's a front wheel drive transaxle.


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## Bugzuki (Jan 15, 2008)

Nice job TheSGC, Is it possible to put the article directly into the Wiki instead of a link?

Just a note. The larger splined shaft sticking out of the tranny is mainly a device to hold the torque converter up - for the internal bearings. It is bolted to the pump housing and the pump housing is bolted to the case. It most likely will not move if you try to turn it by hand. I could be wrong but that is how it is most of the time. 

The pump is turned by the outer sleave of the TC that sticks into the tranny.

Otherwise it is a good article - maybe read through it again and check for grammer/missing words.

Good luck 
Paul


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## TheSGC (Nov 15, 2007)

When I get home today I will take a look at that larger shaft and see if it spins. Yep, I'll go back and edit the article for any mistakes and post it to the wiki. Making the PDF was dirt easy when I did it last night, but I can put the whole thing in the Wiki with pictures once I get those up there.


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## ngrimm (Oct 19, 2007)

I'm anxious to see how this works since some of what we view as torque converter slipping may actually be torque multiplication. I wonder if there is a lower stall converter available for some of these applications. For example one from a 4x4 truck would stall at much lower rpms if used on a light car. I learned the hard way when doing an engine swap. I installed the converter from a car into a heavy 4x4 truck. When idling on a slight incline it would just roll backwards. Doh! Norm


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## TheSGC (Nov 15, 2007)

ngrimm said:


> I'm anxious to see how this works since some of what we view as torque converter slipping may actually be torque multiplication. I wonder if there is a lower stall converter available for some of these applications. For example one from a 4x4 truck would stall at much lower rpms if used on a light car. I learned the hard way when doing an engine swap. I installed the converter from a car into a heavy 4x4 truck. When idling on a slight incline it would just roll backwards. Doh! Norm


I am really hoping for some torque multiplication for more low end acceleration and overall performance. My current thought pattern is that the torque converter might allow for smaller motors to be used in cars. For instance, the K99-4007 motor I am using is a 10 HP 6.7 inch ADC. Normally an 8 inch would be used in this size car but I can't afford one. And I really hope a torque converter does what it's supposed to and convert little torque to lots of torque.


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## ww321q (Mar 28, 2008)

I wonder if this is going to use less amps when taking off ? Seems to me that the TC would let the motor spin faster and in turn use less amps . Humm ? Interesting ! I have an auto trans that I might play around with . J.W.


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## KiwiEV (Jul 26, 2007)

Interesting stuff! So you say that auto 'box has two shafts in one, does anyone have a close-up of an auto gearbox shaft? I'd like to see that.


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## Bugzuki (Jan 15, 2008)

ngrimm said:


> I'm anxious to see how this works since some of what we view as torque converter slipping may actually be torque multiplication.


That would be cool - but, my theory is that Torque multiplication is just a fancy word for slip. The slip just allows the car to move at low RPMs with out stalling.

Just like Freeze plugs. There were holes put into the block to hold the core material during casting. Then, later on, one of the manufacturers noticed that in freezing conditions the hole plugs popped out (once in awhile). So, they came up with a selling point and started calling them Freeze plugs.

I think they came up with the same idea with torque converter slip and called it torque multiplication, because it allows a low RPM/ low torque motor to work without stalling. 

Hope I am wrong.



KiwiEV said:


> Interesting stuff! So you say that auto 'box has two shafts in one, does anyone have a close-up of an auto gearbox shaft? I'd like to see that.


Yes, there are two shafts in one. The outer is hollow with bushings in it.The other shaft goes through it. It engages the TC on the front and the tranny input clutches on the other side. Sorry no pictures.


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## MrCrabs (Mar 7, 2008)

KiwiEV said:


> Interesting stuff! So you say that auto 'box has two shafts in one, does anyone have a close-up of an auto gearbox shaft? I'd like to see that.


Here is an auto tranny

http://www.importperformancetrans.com/images/trans/chrysler/a618.jpg

Here is an exploded torque converter.

http://www.ratstangrestoration.com/converter_exploded_view.jpg

The impeller pump goes around both tranny shafts and drives a pump inside the transmission to build up the ATF pressure.
The stator is connected to the larger shaft coming out of the transmission. This shaft is fixed, but the stator is on a 1 way clutch, so it can rotate forward, but not backwards.
The turbine is connected to the smaller shaft coming out of the transmission, which is the input to the tranny.

The general idea is the impeller pump is attached to the engine flywheel, so they always spin at the same RPM.
Fluid spins around with the impeller pump, and then hits the turbine, causing the turbine to rotate (and the input shaft since they are connected).
The fluid then hits the stator, and pushes against the 1-way clutch. The stator doesnt move and redirects the fluid so it enters the impeller pump in the direction that the impeller is rotating. Once the turbine and impeller are going the same speed, the fluid will hit the stator and try and rotate the stator the same way as the turbine and impeller. The 1-way clutch lets the stator move in this direction. At this point all 3 parts are moving at almost the same speed.

See http://www.familycar.com/Transmission.htm for more info.
It is a pretty good overview of how an auto works, with a decent section on the TC. It was the best explanation I found for a non gear-head.


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## ngrimm (Oct 19, 2007)

I used to think that too but no, it isn't just slippage. As they stated in the link that was just given "If the turbine is moving considerably slower than the pump, the fluid will make contact with the front of the stator fins which push the stator into the one way clutch and prevent it from turning. With the stator stopped, the fluid is directed by the stator fins to re-enter the pump at a "helping" angle providing a torque increase." Even tho there is some slippage going on, it actually changes the leverage just like changing to a lower gear. Unlike a centrifugal clutch which engages when the rpm's increase with no torque increase. I guess we'll see. Norm


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## Bugzuki (Jan 15, 2008)

I guess I did not understand the function of the stator - and probably still don't. This is a good picture from that Family Car site.


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## MrCrabs (Mar 7, 2008)

Here is my list of ideas for using an Auto. I have a 1986 Buick Regal (my current daily driver) that I would love to convert, and turn into a daily driver EV, and show it off at car shows.
The problem is the dang automatic transmission...
So far these are the ideas I have come up with...

1) Use the auto in its stock form. - This would require finding a motor that turns/redlines at the same RPMs as the current ICE.

2) Change the governor in the transmission to increase the shift point to match the new electric motor. This might be easier for some transmissions.

3) Install a manual valve body to take full control of the shifting. This also depends on the transmission. (If the tranny is electronically controlled, a microprocessor/circuit could be built to give you manual control)

All 3 of these options still need the electric motor idling to build up pressure in the transmission, to hold the gear...

I have been looking for some kind of external pump system, to create the hydraulic pressure needed for the transmission, but I don't think there is anything out there "off the shelf" to do this. Anyone find anything like this?

In addition to the transmission changes, a lockup torque converter would be needed to improve efficency. Put a switch in to lock/unlock or build a circuit to do it automatically at a certain speed.

I'm just throwing these ideas out here for discussion if anyone else is thinking about doing the same thing. I know the KISS principle would be to simply idle the electric motor, and leave everything else stock, but in an EV every bit of efficiency is needed to get a good range.


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## JRP3 (Mar 7, 2008)

Seems to me the energy required would be the same for an external pump or an idling drive motor. I still like the idea of a pressure tank, if it would provide enough pressure.


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## Coley (Jul 26, 2007)

The stator's job is to redirect the fluid against the driven turbine to increase the torque on the input shaft, at slow speeds. 
It does this until the vehicle gets up tom speed and then rotates with the converter as a semi solid hookup. The lockup clutch then takes over and does make it a solid connection to the trans input shaft.
The stator changes a fluid drive coupleing, to a torque converter.

Quote:
"Just like Freeze plugs. There were holes put into the block to hold the core material during casting."

No, they were put in to clean out the core sand, after the block was cast.


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## peggus (Feb 18, 2008)

If anybody is interested, I have a Datsun automatic transmission that has been modified to use an external pump when the motor is not spinning. The shift points have been changed to better suit an EV motor. It also comes with an adapter plate for a 9" advance DC type motor and a 1 HP hydraulic pump. The pump motor is shunt wound 120V and requires no controller, just a contactor. 

There are some pictures here:
http://www.electric-lemon.com/?q=node/195

I could really use the extra space in the garage.

It is located in Los Angeles


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## MrCrabs (Mar 7, 2008)

JRP3 said:


> Seems to me the energy required would be the same for an external pump or an idling drive motor. I still like the idea of a pressure tank, if it would provide enough pressure.


You would be able to run an external pump/motor at its peak efficiency vs idling the main motor. However I dont think its an option, unless you want to re-engineer the pump that is already inside an automatic transmission.

The more I research, the more it seems like idling the most is the most elegant solution to use an automatic. KISS for the win!


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## MrCrabs (Mar 7, 2008)

peggus said:


> If anybody is interested, I have a Datsun automatic transmission that has been modified to use an external pump when the motor is not spinning. The shift points have been changed to better suit an EV motor. It also comes with an adapter plate for a 9" advance DC type motor and a 1 HP hydraulic pump. The pump motor is shunt wound 120V and requires no controller, just a contactor.
> 
> There are some pictures here:
> http://www.electric-lemon.com/?q=node/195
> ...


Wow, so nice to know that someone has already "been there, done that". Do you have any idea what they did to the transmission, ie, where does that external pump get fluid from/send fluid to?

Guess its time to find a service/repair manual for my transmission and see what I can come up with!

I'm in Western NY, so I'm gunna pass on it, but thanks for the info.


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## demolay rules (Feb 28, 2008)

Just curious, but how much are you looking for?


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## JRP3 (Mar 7, 2008)

There is an interesting discussion on the EVDL right now about using automatics. Check it out.


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## Bugzuki (Jan 15, 2008)

What is the EVDL? 

But, automatic EVs are the wave of the future.


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## JRP3 (Mar 7, 2008)

Bugzuki said:


> What is the EVDL?


The Electric Vehicle Discussion List. Probably the best place for EV information, unfortunately it's a mailing list not a real forum, but posts can be viewed here on this forum:
http://www.diyelectriccar.com/forums/forumdisplay.php/evdl-list-15.html
Home page and subscription info:
http://www.evdl.org/index.html


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## JRP3 (Mar 7, 2008)

Bugzuki said:


> But, automatic EVs are the wave of the future.


Actually I think the future is high revving AC motors with no transmission or single speed trans ala Tesla.


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## Bugzuki (Jan 15, 2008)

JRP3 said:


> Actually I think the future is high revving AC motors with no transmission or single speed trans ala Tesla.


I think that each motor has an efficiency band - with a smaller area of peek efficiency. The RPM range goes in and out of that band. I think that to get the best efficiency you need to have some way of changing gear ratios to be able to drive at a given speed and be within that band. Like driving in town at 25mph then going on the freeway at 60mph. I think in the long run a CVT would be the best option. Then the computer could always hold the motor speed in the peek efficiency range.

Just my 2 cents - I could be wrong.


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## JRP3 (Mar 7, 2008)

Well the EV1 and the Tesla both run single speed, maybe the RAV4EV as well. Tesla originally planned a 2 speed but that was mainly to get supercar 0-60 times and still retain a 130 top end. Most people don't need either. With the single speed the Tesla still gets sub 5 0-60 and 125 top end I believe. Removing the trans completely would also reduce cost, complexity, and weight.


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## aeroscott (Jan 5, 2008)

whatever you save in the perfect rpm range you give back in heat in the transmission . at 175 lbs for a trans I would put in the heaver slower turning motor with lots of low end torque and nice 2000 to 3000 rpm cruse . no 5000 watts of power lost , no trans service ,no dripping oil ,no shifts . if doing a dc motor the cost of a larger motor may be prohibitive . as i'm working on ac industrial motors that weigh 200 lbs and cost new $1300 for the high end ones .looked at one that weighed 290 lbs 25 hp @1775 rpm . with extra cooling that number could be much greater . still the same weight as trans and motor . this monster could smoke the tires off the car . 91% eff. rated .


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## MrCrabs (Mar 7, 2008)

Yeah, the motor is cheaper, but the controllers are more expensive.
Plus you need a higher voltage pack, but can get away with less Ah...
The configurations I thinking about just seemed to require too many batteries to fit, unless using a truck/suv.
I was thinking of using a Yaskawa VFD (thats the brand I'm most familiar with) with a run of the mill AC motor.


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## TimT (Apr 10, 2008)

http://www.tciauto.com/Products/CircleTrack/circle_track_pump_drives.asp

Sorry didn't read all 15 pages just sort of skimmed. So if this was covered....Anyways TCI makes a converter less adapter. (see link above) Its quite common in dirt track racing. basicly its a shaft that connects the flywheel to the front pump of the transmission. You will also need to add a cooler to keep the fluid cool. Those are readally avalable at any auto parts store. 

Tim


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## Coley (Jul 26, 2007)

Without the TC, on the street you wouldn't need a cooler either.

Most heat from an automatic, is made in the TC and picked up from the ICE...


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## TheSGC (Nov 15, 2007)

I just have to add that the transmission for my 1996 Civic LX weighs in at about 130 LBs with torque converter. It's one heavy beast!


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## DVR (Apr 10, 2008)

Its funny,
KIWIEV started this thread to explain to newb's "The Reasons why Automatic Gearboxes Won't Work with EV's".

Thats what he NAMED THE THREAD for crying out loud!!
And yet, just about all I've read here is how people plan to do it anyway.

ROFL!!!!

KIWI WHAT HAVE YOU DONE!!!!!!!!!!!


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## MrCrabs (Mar 7, 2008)

He used that reverse psychology on us... Or should it be called Down Under psychology 

In my neck of the woods its much harder to find a manual transmission.


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## jlsawell (Apr 4, 2008)

Oh Come on DVR, how many of the people in here are engineers? Saying it can't be done is like a red flag to a bull. 

Definitely reverse psychology, IMHO.

I was planning to convert a 1989 Nissan Pulsar N13 (Auto) but my wife likes it too much to see it butchered in our first attempt at a conversion (it will probably be the second conversion).

So, now I'm on the lookout for a "new" donor car and I'll make this one a manual and basically follow Gav's conversion step by step. Fortunately, here in Brisbane there are both manuals and autos readily available.


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## Arniem (Apr 24, 2008)

This discussion on adapting an auto transmission for EV use pulls together some thoughts I've had on exactly this topic. 

First, in my part of the world there is still a good mix of manual and auto cars to choose from as donors, but I would say the nicer/coolest cars tend to be autos, hence the interest in adapting them as EVs.
Second, the fact the auto transmission needs at least some RPM from the motor in order to maintain oil pressure within the transmission (to prime clutches and bands) ties in well with the need to operate power steering pumps and A/C compressors (and even altenators). Use a double-ended motor, one side driving the transmission, the other side driving pulleys to run the accessories. Then there will always be P/S and A/C, even at standstill or parking speeds. I particularly like how LionEV, in their DIY Ranger conversion, reuse the brackets that mount the ICE P/S, A/C, and alternator, and attaches it to the front of the motor by a solid metal board. Of course, there is the downside of having a parasitic draw against the battery pack at all times, but other threads here suggest that powering the accessories and external transmission oil pump by separate motors which only engage when needed vs using the traction motor doesn't really amount to much of a difference for battery range. And maybe even simpler.

The conversion I am modelling is converting an early 1990s Mercedes 190E auto (one of the lighter Mercs, beautifully designed and built, great size, cheap, easy parts availability, plenty of room to work within). Trouble is, it uses a 4sp hydraulic automatic, so I am working out ways to alter the shift points to keep the motor RPM high enough to reduce the current it draws while delivering the torque needed - trick the vacuum modulator? tweak the Bowden cable? bypass the hydraulic shift valves and use electric-hydraulic valves? alter the governor springs?. Any ideas would be welcome.

If you are planning to convert a later model car which uses an electrically controlled auto box, the job appears easier. Nearly all small cars from mid-1990s onward use such transmissions. I came across, for example, the wiring diagram for the transmissions used in 1990s Ford Laser/Escort, Tracer, Mazda 323/Protege (model F4EAT). http://www.zoom-tech.com/downloads/support/tranxpages/ford/4eat-f.pdf . At its clunkiest you could use a rotary switch to engage the right solenoids to select the gear you want. More sophisticated, you could use a microcontroller to measure roadspeed, motor RPM, current draw, etc, and fire the right solenoids for the gear you need. 

Now, could a real auto-engineer knock some sense into me??..


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## JRP3 (Mar 7, 2008)

Why not just use the shift lever to change gears when you want to? I often do that anyway with an automatic for performance or engine braking.


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## TheSGC (Nov 15, 2007)

Just something I have to add to make your minds wonder:

Yes, and automatic has to idle. Simple, effective solution, but people are saying it uses up more juice. Well, here is something to consider. When a DC motor first starts up, its uses a sizable amount of AMPs to get it moving from 0 RPM, like it would in a manual setup. That is why a lot of stop and go traffic is an enemy for an EV, and uses upwards of 200-300 AMPS to accelerate. Well, if the motor is already spinning at a slow pace and only using 15 AMPS, it will use less AMPS to increase the speed.

I will give an example, using a 12 volt deep cycle as the battery: I am currently buiding the part of my controller that will idle the motor at 625 RPMs (12 volts) and I have a few interesting things. When the motor is at a dead stop and I hit the throttle, it will use 22 AMPs to get the motor moving, and then it will slowly go down to 15 AMPs. But if I throttle the motor down a bit, so it is using 10 AMPs (and low RPMs), then hit the throttle back to full, it will just go back up to 15 AMPs. 

I did this with no load, and pretty shot battery which finally gave out completely today, but I plan on getting a new battery and doing more tests, make a video a post my findings on my website.

So, I am saying that the loss in the automatic might actually be good for city driving and stop and go situations, since it may use a lot less amps to accelerate again.


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## mattW (Sep 14, 2007)

Someone should really write a wiki about the various options for using an automatic, has anyone followed this thread all the way through?


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## KiwiEV (Jul 26, 2007)

DVR said:


> Its funny,
> KIWIEV started this thread to explain to newb's "The Reasons why Automatic Gearboxes Won't Work with EV's".
> 
> Thats what he NAMED THE THREAD for crying out loud!!
> ...


LOL
Yeah this thread has turned into a monster!


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## joseph3354 (Apr 2, 2008)

man is this a long thread! maybe another sticky is in order.might lower the number of postings a tad.i know i'm probably posting too much myself!

edit:i meant the number of postings asking if automatics work for an ev.


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## jlsawell (Apr 4, 2008)

TheSGC said:


> I must be the crazy odd-ball out or something, but I am actually using an automatic transmission. Modern auto trannys (1996+ maybe even older) base the shifting on inputs from the engine RPM, temperature, oxygen sensors and whatever else, but they are all digital signals. I am building a microcontroller that mimics the original ICE, but does all the conversions and spits out useful working data. For instance, my Civic's auto tranny shifts at 2800-3000 RPM, so I would program the controller to shift when the motors hits its "shifting" time, say 5000 RPM, but the tranny will recieve a 2800 RPM signal, and then shift. The lock-out conveter is also electronically controller, and that will also be incorporated into the microcontroller, and activated when the vehicle is in motion.


I'll put my hand up and start the wiki on auto transmission. I've got some info but TheSGC, I'd love some more technical info on that microprocessor. A schematic diagram with some pics maybe? My plan for the Pulsar is to try and use only N, R and 2 until I can build a switch/sensor to use the rest of the gears.


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## lazzer408 (May 18, 2008)

An automatic trans (not electronically or limited electronic shifting) will work. The torque curve is differnet on the electric motor but the trans "knows" how and when to use whatever rpm and torque is comming in to get the most power out of it. Same as it did for the ice. If it has to shift it'll shift. If it doesn't it won't.

As far as removing the torque convertor... you -can- remove the torque convertor as long as you couple your motor shaft to the input shaft of the trans and weld the notched piece you'll cut off the old convertor (that drives the pump) onto the end of the splined hub your also going to be making. The fluid can just circulate inside the adaptor hub. The convertor itself is not part of the oil pump. It just drives the pump which is located in the front of the case. This will also dumb down your transmission and shifting will be harder and probably be at the wrong time considering it senses pressures in the convertor and the oil pump to determine the shift points. You won't loose overdrive. You'll only loose tcc lockup. In reality you'll always be in tcc lockup.  The electronically shifted transmission might actually be a better idea if you could control the shift point yourself. Perhapse a bunch of switches could be wired up for manual shifting of your automatic transmission. It's just 12v solinoids in the valve body that shift it.
My $.02

EDIT- Better yet, use a freq to voltage convertor and a few compaarators (one for each gear) to control your solinoids. Put a magnet on the shaft and a sensor in the bellhousing. I'm thinking there's some logic and/or/not/etc gates in there somewhere to run the gears in sequence. No 2nd or 3rd or 4th until 1st is at 3500rpm. No 3rd or 4th until 2nd is at 3500rpm. Then no 4th until 3rd is at 3500rpm. I could figured it out all analog I'm sure. =)


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## jlsawell (Apr 4, 2008)

The plot thickens! Not all transmissions are created equal, but some are easier to hook an Electric Motor up to than others!

Here's an edited version of the last post on my blog:

The auto transmission in my Pulsar is a hydraulic box, not an electronic one. This means there is no sensor/solenoid combination to fool. Instead, there is a governor that controls the amount of oil going to to little clutches in the box and controlling when to change gears.

So: I just need to modify the governor to change gears at an appropriate time for the electric motor, rather than the ICE. I need to sit down and map together the RPM and torque curves for the ICE and EM, then figure out how to slow the governor. At the moment, I'm looking at something like this:

EV RPM : Governor thinks it is : RPM Result
100 : 800 : Idle
1000 : 4000 at 20km/h : Shift into 2nd
2000 : 4000 at 40km/h : Shift into 3rd
4500 : 4000 at 60km/h : Shift into 4th

The RPMs arent exact, I'm just pulling figures out of my posterior, but you get the idea. Maybe shaving some metal off the governor or plugging the tube with some chewing gum will do the trick? Any other ideas?

As a last resort, I can hook up an oil pump and sensor/controller to regulate the flow of oil, but that's more expensive and complicated than I'd prefer.

So that's the plan. Still loads of work to do but I'm really excited.

Do you think I can find ANY information on the web about a auto transaxle governor? I may have to pay a visit to my local auto transmission workshop and have a chat with the boyz.

<Shameless promotion> Please feel free to link my blog to your sites. And please click on one or two of the google ads - they generate a bit of cashflow and I always try to click on EV blog ads that I see because I know every bit helps! </Shameless promotion>


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## lazzer408 (May 18, 2008)

jlsawell said:


> The plot thickens! Not all transmissions are created equal, but some are easier to hook an Electric Motor up to than others!
> 
> Here's an edited version of the last post on my blog:
> 
> ...


Chances are you'll be making some mods to the valve body. Adjusting springs to change pressures and whatnot. The trans shop is a good start since most of those mechanics have gone to class and should understand the basics behind any automatic transmission.


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## jlsawell (Apr 4, 2008)

lazzer408 said:


> Chances are you'll be making some mods to the valve body. Adjusting springs to change pressures and whatnot. The trans shop is a good start since most of those mechanics have gone to class and should understand the basics behind any automatic transmission.


Yes, that's stage 1. Stage 2 is to figure out how the hell to get regen from an auto transmission (how do I allow the motor to run backwards without mutilating and killing the transmission in a spectacular eruption?)

Anyone have the inside intel on how GM did it with the EV1?


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## John (Sep 11, 2007)

I believe the EV1 was a fixed single ratio transmission not an auto as such. Drive, neutral, reverse, and regen being electrically derived.


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## Coley (Jul 26, 2007)

jlsawell said:


> Yes, that's stage 1. Stage 2 is to figure out how the hell to get regen from an auto transmission (how do I allow the motor to run backwards without mutilating and killing the transmission in a spectacular eruption?)
> 
> Anyone have the inside intel on how GM did it with the EV1?


Mmmnn... your motor doesn't run backwards to regen.....it just gets turned into a generator.....


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## jlsawell (Apr 4, 2008)

Coley said:


> Mmmnn... your motor doesn't run backwards to regen.....it just gets turned into a generator.....


 I'm learning something every day... 

Looks like I need to do some more reading about regen.

In further news...I've been reading about auto boxes voraciously. The fully hydraulic transaxle governor seems to have two components:
The first is the actual governor shaft that sits inside the engine under the governor cap. The second is a linkage on the OUTSIDE of the transaxle case which seems to be a throttle connection. Looks like it's designed to keep the transaxle in gear longer while it's under load.

So my homework looks like it's doubled: I now need to know how to modify both the governor shaft and the external linkage to match the torque of the electric motor, instead of the ICE. I'm looking forward to the challenge!

Does anyone on here know anything about auto transaxles? I'd really appreciate some technical input on modifying the governor...


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## jlsawell (Apr 4, 2008)

Coley said:


> Mmmnn... your motor doesn't run backwards to regen.....it just gets turned into a generator.....


Driving to work this morning I was playing with the transmission and thinking about this regen issue.

When I approach a red light, I can downshift using the stick into 2 and the motor will rev higher, but slow the car down without using brakes. At low speed, I need to use the brakes as the motor braking fades out at low speeds (just like regen braking). And that's what got me thinking.

How about a push-button on the auto stick to activate regen braking like this:

Driving along, I see the lights go orange. So I take my foot off the throttle (motor starts to rev slower). Then I downshift into 2 and squeeze the regen button with my trigger finger. This takes the torque from the tyres to the motor via the gearbox and provides a trickle of power to the batteries. As the regen fades out I use the footbrake to come to a stop. While stopped the motor is idling just enough to keep the torque converter spinning. I release the regen button and pop the shifter back into D. When the lights turn green I accellerate away and the transmission will sense the torque/throttle ratio and shift accordingly.

Sounds great, so what am I missing? If the ICE just revs higher when I downshift, what effect will setting the EM to regen do? Will the motor just stop regenning once there is no torque coming from the wheels?

Do I need to set this up in the controller? Something like "start regen when the button is pressed and stop regen when the revs drop to 800. Then remain spinning at 800 until the throttle says "go"?

Lots to learn, but I think it will work. Spoil my day by thinking of more stuff I need to consider.


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## mattW (Sep 14, 2007)

It depends on a lot of factors. If you are using an AC motor, your controller will work this out itself (you may need an additional pot to the accelerator one to control the regen i.e. one pot for acceleration one for deceleration). If you are using a PM DC motor and buy a controller @ <96V that supports regen then as long as the rpms produce a voltage higher than the battery voltage you should get some battery charging. Using a series wound DC motor means the controller has to send some current to the coils of the motor to start it acting like a generator (called energising the fields) and then allow the current that regen produces to keep the process going (much trickier). All motors over 96V need to have their brush timing advanced which means that during regen some sparking might occur. Its all very complicated and dependant on your motor and how you want to set up the controls.


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## Coley (Jul 26, 2007)

Sounds like a plan.

I would experiment with the idle speed, though. You may find that it will only need 200 rpm to keep oil pressure up enough in the trans. 

That would give you more regen on the stops


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## lazzer408 (May 18, 2008)

Why are you guys trying to 'idle' the motor to maintain pressure?


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## Coley (Jul 26, 2007)

lazzer408 said:


> Why are you guys trying to 'idle' the motor to maintain pressure?


Because then the trans will operate from a dead stop, just as it did when the car was ICE powered.

No hesitation, from not having oil pressure to having pressure. Less wear on the bands, clutches etc. also.


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## lazzer408 (May 18, 2008)

A throttle ramp should be enough. This would give the trans time to engauge. Wear wouldn't be an issue for a wet clutch at that low rpm. I've started ic engines with an automatic in gear and trust me it's pretty fast. No sooner is the engine started it's already in gear. Bypass your neutral safety, at your own risk, and see how quick it is. Then you'll know for sure.

'Idling' the electric motor, to power a hydraulic pump, is a _*huge*_ waste of enegry that could be easily avoided by either not doing it or going manual.

$.02


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## JRP3 (Mar 7, 2008)

The way I understand it common brushed DC motors don't do regen at high voltages because it kills the brushes and controllers aren't setup for it for that reason. One way I've seen people do regen with DC is to have a high output alternator setup with an air conditioner clutch type pulley on the front motor shaft. It freewheels until you hit the brakes, then a brake switch engages the pulley and powers the alternator field which then generates power to the pack.
While regen would be nice I don't think you get all that much, maybe 10%, so 5 miles added to your 50 mile range. You can probably come close to that with careful planning as you drive.


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## TheSGC (Nov 15, 2007)

lazzer408 said:


> A throttle ramp should be enough. This would give the trans time to engauge. Wear wouldn't be an issue for a wet clutch at that low rpm. I've started ic engines with an automatic in gear and trust me it's pretty fast. No sooner is the engine started it's already in gear. Bypass your neutral safety, at your own risk, and see how quick it is. Then you'll know for sure.
> 
> 'Idling' the electric motor, to power a hydraulic pump, is a _*huge*_ waste of enegry that could be easily avoided by either not doing it or going manual.
> 
> $.02


We really have yet to see how much power is wasted. Accelerating a dc motor from a dead stop uses a lot of power, but having the motor ramp up from a low rpm uses considerably less power, so we will see. 

I have to idle my motor because if it stops, the transmission disnegages and there is no way around it. I then have to start the car again in neutral, put it into park, then put in back into drive before it will reengage. Honda has a rediculous amount of safety features in their transmissions.


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## lazzer408 (May 18, 2008)

TheSGC said:


> Accelerating a dc motor from a dead stop uses a lot of power, but having the motor ramp up from a low rpm uses considerably less power, so we will see.
> 
> 
> > It takes W-enegry to push a M-lb vehicle to S-mph in T-amount of time. It takes a certain amount of enegry to move the car. Anything else is wasted enegry not moving the car. You can look at it 50 different ways but bottom line is idling waste enegry. Driving your EV is simply a matter of energy conversion. The available energy is in your battery. To spin that motor for any reason, other then moving the car, is consuming your available energy for something other then moving the car.


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## ngrimm (Oct 19, 2007)

lazzer408 said:


> TheSGC said:
> 
> 
> > Accelerating a dc motor from a dead stop uses a lot of power, but having the motor ramp up from a low rpm uses considerably less power, so we will see.
> ...


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## John (Sep 11, 2007)

JRP3 said:


> While regen would be nice I don't think you get all that much, maybe 10%, so 5 miles added to your 50 mile range. You can probably come close to that with careful planning as you drive.


People’s mileage out of regen varies quite a bit depending on what sort of driving they do. Dense inner city driving would I think yield the best results where distances between stops is short so the vehicle spends most of its time either accelerating or braking. Highway driving would yield the worst results as hardly any braking occures. 

The kinetic energy carried by a vehicle is equal to half its mass times its velocity squared. In SI units mass = kg, velocity = m/s, and energy = J (joules). So for a 1500 kg (3300 lb) vehicle doing 100 kph (27.78 m/s, 62mph), KE = 1500/2 x 27.78^2 = 579 kJ. A Joule is basically a Watt-second so divide by 3600 to convert to watt-hours. 579 kJ becomes 160 Wh. So braking from 100 kph to zero entirely with regen might yield 160 Wh. Say 80% regen efficiency times 65% charge recovery from the batteries times 85% controller-motor efficiency would yield 44% of that energy available for the next acceleration or about 71 Wh. The battery drain saved over non regen would be closer to 83 Wh. If the velocity braked from was a more likely 50 kph this would become 21 Wh (1/4). Don't forget this assumes 100% regen with no friction braking. Multiply this by the number of stops to get battery drain saved.


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## jlsawell (Apr 4, 2008)

lazzer408 said:


> I've started ic engines with an automatic in gear and trust me it's pretty fast.


Lazzer, could you explain how the auto transmission allowed you to start the engine while it was in gear? I had to read your comment twice to make sure I wasn't hallucinating... Sounds pretty dangerous to the clutches and I imagine you'd get a large jerking movement in the vehicle each time you did that.

I'd love to know how your experiences were using this procedure.

With regard to the second shaft: I'm planning to use it to operate the vacuum pump for the brakes and the alternator for the 12v electrics. Regenning of that may well be an option. Allowing it to freewheel has given me another idea that might save a few volts: installing a gauge & switch on the dash for the 12v battery and only run the alternator when the battery drops below 50%.


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## Manntis (May 22, 2008)

jlsawell said:


> With regard to the second shaft: I'm planning to use it to operate the vacuum pump for the brakes and the alternator for the 12v electrics.


How large a vacuum reservoir are you using? Powering the brake vacuum pump only when the motor is running is a tricky proposition. At low speeds or when stopped on an incline/decline you could run out of brake vacuum assist fairly quickly. Further, you may consider hooking the alternator to a 12V battery as redundant backup so you don't lose your lighting and other accessories in event of an alternator failure.


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## Manntis (May 22, 2008)

John said:


> People’s mileage out of regen varies quite a bit depending on what sort of driving they do. Dense inner city driving would I think yield the best results where distances between stops is short so the vehicle spends most of its time either accelerating or braking. Highway driving would yield the worst results as hardly any braking occures.
> 
> The kinetic energy carried by a vehicle is equal to half its mass times its velocity squared. In SI units mass = kg, velocity = m/s, and energy = J (joules). So for a 1500 kg (3300 lb) vehicle doing 100 kph (27.78 m/s, 62mph), KE = 1500/2 x 27.78^2 = 579 kJ. A Joule is basically a Watt-second so divide by 3600 to convert to watt-hours. 579 kJ becomes 160 Wh. So braking from 100 kph to zero entirely with regen might yield 160 Wh. Say 80% regen efficiency times 65% charge recovery from the batteries times 85% controller-motor efficiency would yield 44% of that energy available for the next acceleration or about 71 Wh. The battery drain saved over non regen would be closer to 83 Wh. If the velocity braked from was a more likely 50 kph this would become 21 Wh (1/4). Don't forget this assumes 100% regen with no friction braking. Multiply this by the number of stops to get battery drain saved.


Great post 

I'd like to add, though, that in some setups regen kicks in simply by lifting off the accelerator so you can regen-brake similar to downshifting in a conventional standard trannie ICE car. Some also contain a selector switch allowing for three-position regen (max regen for in-town stop and go driving, reduced regen for increased coasting, and almost no regen with no motor 'drag' when coasting, suitable for highway driving)


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## lazzer408 (May 18, 2008)

jlsawell said:


> Lazzer, could you explain how the auto transmission allowed you to start the engine while it was in gear? I had to read your comment twice to make sure I wasn't hallucinating... Sounds pretty dangerous to the clutches and I imagine you'd get a large jerking movement in the vehicle each time you did that.
> 
> I'd love to know how your experiences were using this procedure.


I didn't have the neutral saftey switch connected so if I turned the key it would crank and start no matter what gear it was in. It takes very little volume of oil to engauge the clutches in an automatic. The pump doesn't have to turn very many times to supply enough oil. The engaugement was no harder then putting your car into drive while at idle. It might almost engauge before the engine got up to idle rpm.

If you want to know what it would feel like. Go to a parking lot where it is safe to do some testing. If your car has a brake interlock to get out of park, try to press the brake pedal -just enough- to allow you to shift out of park without actually applying the brakes. You'll feel what it like for the car to engauge into drive without the brakes applied. It's not a sudden shock like u may think mainly due to the torque convertor design to 'slip' at low rpm. Also note the time it took for drive to engauge. ~1/2 second? If the electric motor was kept below ~1000rpm for that brief period it would feel no different.

I'm was an auto mechanic for years. I've done everything from tune-ups to rebuilding engines and automatic and manual transmissions. I turbocharged my Mazda MX-3 and Miata out of misc. parts from GM, Ford, Saab, Mitsubishi, International Harvestor, and a handfull of home-made parts all rolled into a little M3 stomping street legal gokart.  Chances are my opinions are'nt just an educated guess but actual experience. If I can help in any way, I'll try.


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## jlsawell (Apr 4, 2008)

mattW said:


> It depends on a lot of factors. If you are using an AC motor, your controller will work this out itself (you may need an additional pot to the accelerator one to control the regen i.e. one pot for acceleration one for deceleration). If you are using a PM DC motor and buy a controller @ <96V that supports regen then as long as the rpms produce a voltage higher than the battery voltage you should get some battery charging. Using a series wound DC motor means the controller has to send some current to the coils of the motor to start it acting like a generator (called energising the fields) and then allow the current that regen produces to keep the process going (much trickier). All motors over 96V need to have their brush timing advanced which means that during regen some sparking might occur. Its all very complicated and dependant on your motor and how you want to set up the controls.


mattW, I've just come across this information at http://jerryrig.com/convert/step37.html

So, while the EV is down and out without a charger I've taken the opportunity to take it partially apart again. The reason this time is to reset the motor advance so it will work better with regen. These motors come with the brushes advanced slightly (in relation to field coils) to provide a slight economy, I believe, in regular forward propulsion. Well, when you start using the motors as both a motor AND a generator this advance setting suddenly becomes the opposite when in regeneration, which can cause arcing and sparking. So I've adjusted the motor (and the end motor mount) to be on the zero advance setting. End Quote

Does this impact on your post? Is it a possible solution?


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## ww321q (Mar 28, 2008)

Thank you lazzer408 !! I was thinking that you could go from zero rpm start in gear and not slip the disks to much . On an older transmission going from a cold start it takes a second or three to get going but when warmed up it's almost instantaneous . J.W.


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## ww321q (Mar 28, 2008)

ww321q said:


> I was just thinking (yea right!) if you still had the ICE motor in the car you could bypass the neutral safety switch and do some tests starting the motor in gear . You could see how long it was till it engaged in gear ...J.W.


 from an earlier post J.W.


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## lazzer408 (May 18, 2008)

fwiw: http://www.poormansev.com/id29.html

He bypassed the torque convertor on a powerglide (2 speed) and made modifications to the trans to manually shift it.

Off his site:

"I cut the torque converter in half with a band saw and had a machine shop torch out the center part that turns the tranny pump. Cut off the tranny input shaft to meet up with the electric motor shaft. Designed piece of metal to connect motor to tranny input shaft and tranny pump. Had machine shop weld it up."

This is exactly what I mentioned when we discussed eliminating the torque convertor but still drive the oil pump. It worked for this guy. 

The powerglide is actually a pretty good idea for an EV.

One thing about transmissions that many people may not know... The transmission is in every gear at once. "Shifting gears" is really only choosing which ratio gets connected to the output shaft. Your not physically changing gears. Your selecting ratios. I mention this because, if you can imagine every gear ratio turning at once, that's alot of parasitic drag.

So...

When someone has a trans laying on the ground with a motor connected to it can you please do some testing. Measure 'no load' current then switch to a thinner oil and test again.


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## JRP3 (Mar 7, 2008)

jlsawell said:


> mattW, I've just come across this information at http://jerryrig.com/convert/step37.html
> 
> So, while the EV is down and out without a charger I've taken the opportunity to take it partially apart again. The reason this time is to reset the motor advance so it will work better with regen. These motors come with the brushes advanced slightly (in relation to field coils) to provide a slight economy, I believe, in regular forward propulsion. Well, when you start using the motors as both a motor AND a generator this advance setting suddenly becomes the opposite when in regeneration, which can cause arcing and sparking. So I've adjusted the motor (and the end motor mount) to be on the zero advance setting. End Quote
> 
> Does this impact on your post? Is it a possible solution?


The problem with that is now most of the time when you are running the motor is not advanced and therefore not timed correctly. This may not be a problem with a lower voltage pack, (I didn't see what he was running), but motors are advanced to work without arcing at higher voltages. That's why a Warp 9 can handle higher voltage than an ADC 9. He's also using a Zapi controller with Regen, and I don't know if they even make them any more.


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## mattW (Sep 14, 2007)

I have heard that above 96V you need advanced timing to avoid sparking which would makes sparking during regen worse. You could probably get away with neutral timing at slightly higher voltages than 96 but either way (advancing or neutral) you are risking sparking. I don't want to pretend I'm an expert on this (i don't even know what the consequences of sparking is) I'm just sharing what I know so far.


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## JRP3 (Mar 7, 2008)

mattW said:


> I don't want to pretend I'm an expert on this (i don't even know what the consequences of sparking is) I'm just sharing what I know so far.


It doesn't sound good 


> "Flashover" is the term for when an arc struck from a brush is carried
> around the comm to the next brush, of opposite polarity. The arc is
> plasma and is electrically conductive. When it touches the other
> brush, your pack is now shorted. Boom! Motor carnage!


Some good information in the EVDL post "Maximum ADC Voltage"
http://www.diyelectriccar.com/forums/showthread.php/evdl-maximum-adc-voltage-14086.html


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## Coley (Jul 26, 2007)

Quote:
"One thing about transmissions that many people may not know... The transmission is in every gear at once. "Shifting gears" is really only choosing which ratio gets connected to the output shaft. Your not physically changing gears. Your selecting ratios. I mention this because, if you can imagine every gear ratio turning at once, that's alot of parasitic drag."


True the internal parts are all turning all the time, but the drag is very minimal.

Eliminating the converter and shifting manually, is NOT using an "automatic" transmission.....just a 2 speed manual box......

Here we go again.....


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## lazzer408 (May 18, 2008)

Coley said:


> Eliminating the converter and shifting manually, is NOT using an "automatic" transmission.....just a 2 speed manual box......


What if said 'convertor-less' transmission is automatically electronically shifted? The computer could ramp down current, perform the shift, and re apply current. It may not even need to do that if it shifted smooth enough. Not much different then a WOT upshift for an ICE.



Coley said:


> Here we go again.....


weeeee I like this ride.


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## DVR (Apr 10, 2008)

Coley said:


> Eliminating the converter and shifting manually, is NOT using an "automatic" transmission.....just a 2 speed manual box......
> 
> Here we go again.....


So what?? People here are trying to work out if they can USE the auto that came in their donor. Who cares if it is "true auto" or "just a 2 speed manual box"
The point is they *may me able to use it.*

The benefits I see are instant changes when you want to change or just leave it in second as you would a manual box.

*IF* they can get it to work, *reliably,* kudos's to em I say


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## KiwiEV (Jul 26, 2007)

There's a nice guy in the USA that's been in contact with me regarding his own EV conversion which is going well. He's using an automatic gearbox and has set up videos on youtube:

Here's his test spin. You can see/hear him gradually changing the shifter up from 1, 2 and 3. He has a sticking brake caliper (I know that feeling):
http://nz.youtube.com/watch?v=MF40bamtuR4

And later his first test run up the street with no pot box or controller just yet:
http://nz.youtube.com/watch?v=nzKjBQkkojU
Gotta love that sparking! 

Good to see he's mastering the auto gearbox. I'm looking forward to see if he's going to have it "idle" when stopped or not.


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## dfwheelman (May 15, 2008)

jlsawell said:


> Lazzer, could you explain how the auto transmission allowed you to start the engine while it was in gear? I had to read your comment twice to make sure I wasn't hallucinating... Sounds pretty dangerous to the clutches and I imagine you'd get a large jerking movement in the vehicle each time you did that.
> 
> I'd love to know how your experiences were using this procedure.
> 
> With regard to the second shaft: I'm planning to use it to operate the vacuum pump for the brakes and the alternator for the 12v electrics. Regenning of that may well be an option. Allowing it to freewheel has given me another idea that might save a few volts: installing a gauge & switch on the dash for the 12v battery and only run the alternator when the battery drops below 50%.



My father taught me that trick a long time ago. Works on older chevys (his hot rod of choice) but I dont know about newer cars. You just need lots of room to get the torque converter spun up.


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## dfwheelman (May 15, 2008)

> "I cut the torque converter in half with a band saw and had a machine shop torch out the center part that turns the tranny pump. Cut off the tranny input shaft to meet up with the electric motor shaft. Designed piece of metal to connect motor to tranny input shaft and tranny pump. Had machine shop weld it up."





> This is exactly what I mentioned when we discussed eliminating the torque convertor but still drive the oil pump. It worked for this guy.


brilliant! now I see an aftermarket idea for automatic shaft couplers


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## dfwheelman (May 15, 2008)

If anyone really wants to understand automatics

http://www.performanceoiltechnology.com/transmission_operation_1.htm


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## FPV_GTp (Mar 25, 2008)

Interesting read guys

My 2 cents worth , i use a clutched turbo400 chevy automatic transmission behind my ford 351Cleveland engine drag racing car.

The engine is coupled to the transmission less the stall convertor . A special input shaft with a spline like a manual box is made up that press fit into the front clutch hub of the t400 also spline that end is used. This input shaft engages into the clutch.

The there is a special three star propeller that has a housing on it that engages into my borg&beck style 11 inch clutch assembly that also engages into the front pump of the t400 automatic transmission. 

When i release the clutch peddle my transmission engages straight away same as a manual transmission does. The only advantage in drag racing with this setup once I'm of the mark I don't need to press the clutch when changing gears > so really its a semiautomatic setup. But coming to a stop I have to press the clutch peddle to prevent the car from moving. 

So I see no issue coupling a automatic to a electric motor , discard the stall convertor , drive the transmission front pump to apply the clutch packs and bands of the transmission.

So pros and cons of using a automatic transmission mmmmmmmmmm , if one wants to have full control of a automatic transmission you will have to use the stall convertor. Also like a lot of you guys discussed on electronic transmission you will need some sort of transmission controller.

Or still utilize the vehicles factory PCM ecu to run the electronics of the transmission.

In one of the posts of tis thread i read some guy was making his own transmission controller ( or a engine simulator/emulator to make the PCM of the car think it is driving the engine and transmission still) ??? how did your transmission controller work ?


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## TheSGC (Nov 15, 2007)

FPV_GTp said:


> In one of the posts of tis thread i read some guy was making his own transmission controller ( or a engine simulator/emulator to make the PCM of the car think it is driving the engine and transmission still) ??? how did your transmission controller work ?


That was probably me, and I haven't gotten that far yet. I have been researching more into the PCM of my Civic and I may not have to do anything for it. Apparently there are a few sensors that detect the speed and torque and shift up and down depending on speed and torque output. It doesn't seem to care for the RPMs since that is the only sensor that is not on the transmission and can drive without it. I am still making my adapter plates and coupler for my transmission and hope to have all the materials for it this week. Then comes the painful task of finding a machine shop.


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## lazzer408 (May 18, 2008)

TheSGC said:


> That was probably me, and I haven't gotten that far yet. I have been researching more into the PCM of my Civic and I may not have to do anything for it. Apparently there are a few sensors that detect the speed and torque and shift up and down depending on speed and torque output. It doesn't seem to care for the RPMs since that is the only sensor that is not on the transmission and can drive without it. I am still making my adapter plates and coupler for my transmission and hope to have all the materials for it this week. Then comes the painful task of finding a machine shop.


Don't forget that some ECUs uses the TPS sensor for kick-down. As far as I know there are few cars who's transmission 'thinks for itself'. There mainly controlled by what the ECU thinks the engine is doing. MAF or MAP readings for engine load and things like that.


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## FPV_GTp (Mar 25, 2008)

TheSGC said:


> That was probably me, and I haven't gotten that far yet. I have been researching more into the PCM of my Civic and I may not have to do anything for it. Apparently there are a few sensors that detect the speed and torque and shift up and down depending on speed and torque output. It doesn't seem to care for the RPMs since that is the only sensor that is not on the transmission and can drive without it. I am still making my adapter plates and coupler for my transmission and hope to have all the materials for it this week. Then comes the painful task of finding a machine shop.


 
Hi TheSGC;46893 ok , have you seen the GP1/0 boards that the guys on MegaSquirt forum are working on a stand alone transmission controller? http://www.msefi.com/index.php

Also i think this place has some Honda Civic tuning software not sure if it is related to transmission tho http://www.moates.net/


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## FPV_GTp (Mar 25, 2008)

hi

Here is a automatic vehicle at Surge Technology's Electric Motor Kit http://www.youtube.com/watch?v=uSQjTv9JyhQ

ELECTRIC VEHICLE SURGE TECHNOLOGY NO BATTERIES NO GAS http://www.youtube.com/watch?v=jt5z8L4LBJE&feature=related


cheers


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## JRP3 (Mar 7, 2008)

Troy Reed later admitted that the motor in those videos was not self sustaining. Big surprise


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## jlsawell (Apr 4, 2008)

Just a quick update on my Auto-EV project. I'm pretty sure I've got the solution to keeping the hydraulic transmission "informed" or "fooled".

I've drawn out the current situation and I'm planning to get my wife's grandfather to do the math/geometry/engineering work to determine the travel distance for the transmission cable. Once I know that, I need to modify the Pot Box arm so it pulls the transmission cable the same distance as the ICE used to. That will keep it in gear while the Electric Motor does it's Jazz.

More details on my blog: http://ev-pulsar.blogspot.com


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## drolsinatas (Jun 9, 2008)

what about rear axle gears?

When i worked construction, the dump trucks had gears in the rear axle that could change.Some changed using air, and other were electronically controlled. Solenoid? Could we adopt these rear ends into our cars?


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## DVR (Apr 10, 2008)

jlsawell said:


> Just a quick update on my Auto-EV project. I'm pretty sure I've got the solution to keeping the hydraulic transmission "informed" or "fooled".
> 
> I've drawn out the current situation and I'm planning to get my wife's grandfather to do the math/geometry/engineering work to determine the travel distance for the transmission cable. Once I know that, I need to modify the Pot Box arm so it pulls the transmission cable the same distance as the ICE used to. That will keep it in gear while the Electric Motor does it's Jazz.
> 
> More details on my blog: http://ev-pulsar.blogspot.com


 I trhink what your playing with is the "kickback leaver" At least that's what I call it I didn't know that they were still used on pulsars, thought they were electronic. What year is yours?

I used to play with the kick back on my old EH Holden. I adjusted it right up so that it revved like crap before it changed. A few years ago I had a kickback cable break on my XF Falcon and it wouldnt change down unless you were allmost at a standstill. I wonder if you could simply lock it up at full open and leave it alone? That would be real simple


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## jlsawell (Apr 4, 2008)

DVR said:


> I didn't know that they were still used on pulsars, thought they were electronic. What year is yours?
> 
> I wonder if you could simply lock it up at full open and leave it alone? That would be real simple


Mine is a 1989 N13 - I think it's the last year they had a hydraulic transmission. Luckily for me or else I'd be like TheSGC, inventing my own little circuit board to fabricate signals. That's out of my league at the moment.

I certainly could lock it open by yanking on the cable and then fixing it to a bolt in the side of the engine bay. I may end up doing just that, but if I can engineer a more elegant process with only a little more effort, that's my goal.

Dunno about rear axle gears - that's another thing way beyond this accountant's engineering skill. I don't even own a welder or a soldering iron yet!


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## JRP3 (Mar 7, 2008)

drolsinatas said:


> what about rear axle gears?
> 
> When i worked construction, the dump trucks had gears in the rear axle that could change.Some changed using air, and other were electronically controlled. Solenoid? Could we adopt these rear ends into our cars?


You're talking about a big, heavy, expensive 2 speed rear end. Not something you'd want in an EV.


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## MrCrabs (Mar 7, 2008)

DVR said:


> I wonder if you could simply lock it up at full open and leave it alone? That would be real simple


According to someone on the EVDL thats exactly what they did on automatic conversions in the past.
They would lock the throttle cable to the Wide Open Throttle position, which would raise the shift points up to a higher road speed/rpm.


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## aeroscott (Jan 5, 2008)

JRP3 said:


> You're talking about a big, heavy, expensive 2 speed rear end. Not something you'd want in an EV.


as best I can recall some pickup trucks and some bmw's had 2 speed aftermarket rear ends . but i've never Sean them . I have the gear vendor in my pickup truck , but it's only 15% overdrive .


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## Coley (Jul 26, 2007)

Your cable setup may help in adjusting the shift points, but your manual lever keeps it in gear....


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## drolsinatas (Jun 9, 2008)

JRP3 said:


> You're talking about a big, heavy, expensive 2 speed rear end. Not something you'd want in an EV.


Of course we wouldn't want an actual rear end from a dump truck. But what about the way the gears are set up inside? I can't find any good links that show diagrams on how the set up works inside the pumpkin to those axles.

The tesla uses a 2 speed electronically controlled type of gear changer. I'm sure its super sophisticated. Just trying to think of an easier cheaper way to get 2 gears.


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## MrCrabs (Mar 7, 2008)

drolsinatas said:


> Just trying to think of an easier cheaper way to get 2 gears.


Has anyone thought about using a transfer case for 2 gears?
I don't know if they can shift from Low to High while moving....

The easiest way to get more than one gear is stick with the tried and true manual tranny conversions. Electronic auto's with an programmable transmission controller would be nice and simple for a driver, but more complicated to build.


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## JRP3 (Mar 7, 2008)

MrCrabs said:


> Has anyone thought about using a transfer case for 2 gears?


Well yes, I have  At some point I'm going to do an EV Jeep and was considering skipping the tranny and just using the T-case, but I'd rather have mechanical reverse as opposed to reversing the motor, since when 4 wheeling I would often need full power reverse, and I'd like more gear choices for off roading.


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## Telco (Jun 28, 2008)

Read the whole thing (whew) and thought I'd throw my nickel's worth in.

Early powerglide transmissions used a rear mounted pump. No pressure at a dead stop. One of these would be ideal for an EV, if you could find one.

GM 4L60E and 4L80Es would be a good choice for this as the computer decides when to shift according to throttle position and vehicle speed. For an electric motor, I can't see the need for a throttle position seeing as it would be a direct drive, and the torque for an electric motor is near flat where for an ICE it is varied by RPM across a large power range.

A torque converter is designed to work with an ICE's characteristics, not an EM's characteristics. It must let the engine run at a dead stop, then allow the engine to move when it builds RPM. Performance torque converters will slip until it reaches the stall speed, which lets the engine start moving the vehicle when it's higher in the RPM band, allowing the engine to move the vehicle at it's most powerful RPM. The torque converter will then catch up to the engine. When you run a powerful engine, and run two different torque converters, the lower stock RPM converter will let engine RPM climb slowly until it reaches the shift point, but a high stall will let RPMs flash to stall almost instantly, then hold steady for a bit, then start climbing. There is also some torque multiplication involved in this, as an ICE has nearly no torque from off idle and needs all the help it can get. Once it's moving it has tons of torque, but not where it needs it. Since an EV has max torque from the getgo, I see no reason to need a torque converter with one. In fact, using a torque converter with a high multiplication could very well tear the back of the car out. Unfortunately, the multiplication is not a fixed value, once the engine is running at a steady state there is no multiplication as it's all done inside the torque converter as a function of the difference in speed between the engine and transmission when accelerating, so it wouldn't do any good trying to use one to use a smaller EM to run the car.

Since the transmission is designed for an ICE, I wouldn't be a bit surprised if there wasn't some sort of pressure relief valve to cut pressure at idle to keep the car from moving at idle, but this is conjecture. Someone would have to have a pressure schematic of the transmission to see if there were. If there is though, plugging that would mean an EV could use one 
without the need to provide an idle speed or a secondary pump. As soon as the EM started moving, the pump would start making enough pressure to run the transmission. Since the early Powerglides (or was it Torqueflights?) were able to operate with no pressure until the rear wheels were turning, a more modern transmission may be adaptable to operate the same way.


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## lazzer408 (May 18, 2008)

Telco said:


> the torque for an electric motor is near flat


Far from it. The lower the RPM the higher the torque and visa-versa. A series motor's -horsepower- is closer to flat.



Telco said:


> Performance torque converters will slip until it reaches the stall speed.


At rated stall speed it's still slipping.


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## Telco (Jun 28, 2008)

lazzer408 said:


> At rated stall speed it's still slipping.


Picky picky. Slippage is nearly nonexistant at speed. When a locking torque converter locks the RPM drop is 200RPM or less. Nothing at all like at takeoff when the slippage is 2700RPM or more, when floored from a dead stop.


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## lazzer408 (May 18, 2008)

Telco said:


> Picky picky. Slippage is nearly nonexistant at speed. When a locking torque converter locks the RPM drop is 200RPM or less. Nothing at all like at takeoff when the slippage is 2700RPM or more, when floored from a dead stop.


I wasn't trying to be picky. If a stall is rated at 3000rpm it's 3000rpm of slipping. If it's rated at 2200rpm that's 2200rpm of slipping. I wanted to explain so people don't think it "stops slipping" at the rated stall speed. Someone might think it actually engauges (stops slipping) at the rated stall. Reguardless, an electric motor won't be dishing out 250lbs of torque at 2200rpm anyways. I guess you could have said the ice's rpm will 'stop climbing' at the stall speed of the convertor.

Some slipping might be an advantage for an EV because the motor's rpm would climb right away rather the stall the shaft until the vehicle is rolling. That should drop the current peaks during take off from a dead stop.


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## Coley (Jul 26, 2007)

Uh...you are forgetting that all powerglides have a front pump. That is what moves the internals, when you step on the gas. 

The rear pump takes over at about 30 mph, to do the major pumping in the trans.

A torque convertor will do what it does for an EV, just what it does for an ICE.

Not a problem. Idling the electric motor, would solve most problems with using an automatic.


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## FPV_GTp (Mar 25, 2008)

Hi

I think some people missed the whole idea of using a automatic transmission in a EV vehicle.

Also the BACK PUMP on the automatic transmission shaft is a governor on the older style transmissions i.e powerglide , T350 , T400 , T700 (OD) , C4 , C10 , C6 , FMX and so on

One does not need a stall convertor to couple a electric motor to a automatic transmission.

A electric motor does not idle at 800rpm when you take you foot of the throttle.

The convertor is a means of coupling the engine crankshaft to a automatic transmission. The convertor has a input shaft that drives a internal pump to engage clutch packs and bands and servo valves to apply them. It is just a case of driving the front transmission pump via a direct link from the electric motor. The transmission will drive of the standing still mark.

One will have to consider the full range of driving conditions ????

So this can be accomplished without a stall convertor all together. A little more complicated setup but it will work ( clutched auto )

BUT

If someone wants to utilize a stall convertor that will lockup at very low electric motor speeds i.e. between 50 to 100rpm it is also possible to have a convertor modified to behave in the characteristics that are required for a electric motor to be coupled up to a automatic.

All/almost late model automatic transmission use a electric solenoid to lockup and unlock the convertor in certain driving conditions again which can be implement in a EV-automatic transmission coupling. with a transmission controller.

cheers


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## lazzer408 (May 18, 2008)

FPV_GTp said:


> Hi
> 
> I think some people missed the whole idea of using a automatic transmission in a EV vehicle.
> 
> ...


You have to drive the input shaft as well. As I mentioned it would be fairly easy to make an adaptor out of the old convertor. You just need to drive the input spline and pump. Shifting could easily be done with switches but it wouldn't be 'automatic' anymore. How about a steped rotory encoder with paddle shifters?


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## Coley (Jul 26, 2007)

Quote:
"Also the BACK PUMP on the automatic transmission shaft is a governor on the older style transmissions i.e powerglide , T350 , T400 , T700 (OD) , C4 , C10 , C6 , FMX and so on"

Wrong....the pump is not a governor.....it is just the main pump for highway speeds. The gov is a seperate item that has it's own job.

Wrong on a stall convertor also. A stall conv. lets the engine rev higher (max torque) before it moves the car. Just the opposite as needed for an EV. They have full torque on the first turn of the shaft.....

You must have read the complete file and be a quick study.....

As you have just repeated the whole idea and still got it wrong! Amazing...


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## lazzer408 (May 18, 2008)

As far as I know the rear pump was an added feature that started with the Corvair so it could be "push started" and as an economy feature.


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## Coley (Jul 26, 2007)

Powerglides, since the first one had both pumps. They dropped the rear pump in about 1965 or so......(saving money).

One side benefit was the ability to be push started, but it was not the primary one.


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## LEVitator (Nov 21, 2007)

Is it true that automatic gearboxes can't handle the torque of an electric motor?


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## LEVitator (Nov 21, 2007)

I was told automatic transmissions can't handle the torque electric motors can provide...or at least the hydrostatic type we currently have in vehicles. Is this true?


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## lazzer408 (May 18, 2008)

LEVitator said:


> I was told automatic transmissions can't handle the torque electric motors can provide...or at least the hydrostatic type we currently have in vehicles. Is this true?


No. It'll hold it just fine.


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## XJJack (Jun 16, 2008)

I was thinking about replacing the torque converter with a 1.5 to 1.75 planitary gear set to get the input shaft speeds closer to what the AT is used to seeing.


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## lazzer408 (May 18, 2008)

XJJack said:


> I was thinking about replacing the torque converter with a 1.5 to 1.75 planitary gear set to get the input shaft speeds closer to what the AT is used to seeing.


Overkill. The electric motor doesn't have some sort of powerband to aim for like an ice does.


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## Coley (Jul 26, 2007)

Umm, why would you want to slow down the input shaft?


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## Telco (Jun 28, 2008)

Hmm, I was unaware the earliest Powerglides had a front pump, thought it just had a rear pump and the front pump was an improvement discovered later on. But, now that I think about it, makes sense that it would need a front pump. Silly me.

A stall converter doesn't just slip to the rated RPM regardless, if you ease into the throttle it will grab and hold just over idle, how high over idle will depend on the stall speed, input power and vehicle weight. In fact, a high stall converter in a light vehicle will allow the vehicle to move in idle with no brake on. There will be some slippage regardless of stall speed until the converter locks, provided it's a locking converter. What's bad is some of the newer GM factory converters are designed to slip all the time regardless of lockup, for comfort purposes. 

Since an ICE is always running, this means that the torque converter will always be spinning that pump. I'd have to wonder if there is a pressure relief in the transmission to keep it from moving even though there is fluid pumping. If there were an idle circuit on there, seeing as the automatic transmission was designed to be operated by an ICE and not an EM, defeating it might allow you to have an auto on an EM without having to "idle" the EM at a stoplight. You'd need a detailed fluid map of the transmission along with a detailed explanation of each leg to find if there were one though. Be nice if there were because the only way I can sell the wife on an EM is if she doesn't have to do a single thing different than she does now, and she won't drive a manual. It's not going to keep me from making myself one, but if there were an effective way for her to have an auto, I could get her into one.


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## morvolts (Jun 19, 2008)

Ive been following this subject with great interest.
My latest EV project has an automatic transaxle
and wont be easy to convert to a manual trans.
Ive been exploring the idea of using a circulating 
pump made for "towed"or"toad" vehicles behind RVs.
This will keep the fluid moving since the torque converter isnt in the system.I think this will prevent the 
bang when you first take off that is a result of the pump catching up to the internal input shaft.
On the subject of newer transmissions being harder to adapt I think the opposite is true.
Electronically controlled transmissions use 2 solenoids
to shift(with 4 forward speeds,more solenoids are needed if more gears are present.)
Its a very simple process of choosing a gear by what the function of that solenoid is .
Most will default to 2 nd gear if no power is applied to the solenoids.
So if you want an electronic trans to stay in 2nd gear leave power to solenoids off.Heres the scheme of just one 
GM trans:
1st solenoid A on 
solenoid B off
2nd solenoid A off 
solenoid B off
3rd solenoid A off
solenoid B on
4th solenoid A on
solenoid B on
You will still want to retain the selector cable or linkages as its used in the operation of the valve body,but if you want to leave it in drive and select a gear all thats needed is solenoid power.


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## TheSGC (Nov 15, 2007)

The reality is that it will probably take the same energy to idle the motor as is takes to add a separate pump.

I have been studying the data on the auto transmission on my Civic and I have to idle the motor because of how the transmission will disengage if the torque converter stops spinning or something to that effect. I have found out that if something goes wrong the transmission will drive in "limp" mode which is essentially 2nd gear.


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## Telco (Jun 28, 2008)

TheSGC said:


> The reality is that it will probably take the same energy to idle the motor as is takes to add a separate pump.
> 
> I have been studying the data on the auto transmission on my Civic and I have to idle the motor because of how the transmission will disengage if the torque converter stops spinning or something to that effect. I have found out that if something goes wrong the transmission will drive in "limp" mode which is essentially 2nd gear.


If that's the case you should be able to lock out 1st gear and eliminate the torque converter. It would then take off in 2nd gear, and by the time the speed was high enough to shift to 3rd the transmission pump would be spinning enough to provide the fluid needed for the next gear. You'd also need to cap off the input shaft so the fluid would circulate back, and perhaps look into a new trans pump that can produce more flow with a slower speed, and recal the transmission to work with the higher pressure. Should be doable, and is just the sort of thing that one would expect to have to do when setting up an auto to work with an EM.


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## lazzer408 (May 18, 2008)

I think you guys underestimate the amount of fluid needed to engauge the bands and clutches. It's not volume that engauges it, it's pressure. Also the torque convertor doesn't do any pumping outside of itself. Think of it as 2 fan blades sealed in a box filled with oil. One to the motor and one to the input shaft of the trans. It's simply a viscous coupler.

Read up here.

http://www.howstuffworks.com/torque-converter.htm

How stuff works mentions part of the converter as a pump but their referring to the internal workings of the converter itself and that pump is not the same as the transmission's oil pump which is located in the front of the trans in most cases. The 'pumping' of the converter itself is the action of the driven turbine (stator).

There is no reason you need to idle the electric motor just because your using an automatic transmission. If your controller has a throttle ramp, as most do, that should be enough time for the transmission to get in gear. If not you'll have to mentally hold back on the throttle for that 1/2 second it takes to engauge before you mash down the throttle.



TheSGC said:


> I have found out that if something goes wrong the transmission will drive in "limp" mode which is essentially 2nd gear.


This indicates the ECU is in control of the transmission and if a fault is detected it will stay in second. Many transmissions even have a feature of locking out first gear if the selector is placed in second. It was called 'snow start' to assist the driver on snow/ice. It will still upshift to 3rd, od, ect. It just won't go into first.


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## morvolts (Jun 19, 2008)

The jest of the post I made is that the controller doesnt do anything except monitor the transmission and engine and determine when it shifts and when it locks up.
This sounds simplified because it really is simple.
Find the shift solenoid pattern that pertains to your model and use that to engage the gears you need.You dont need a controller unless you re looking for seamless,buttery smooth shifts in a true automatic position. The reason I suggest an external pump to run is that it will prevent the lag or jerk when first accelerating.


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## lazzer408 (May 18, 2008)

morvolts said:


> The reason I suggest an external pump to run is that it will prevent the lag or jerk when first accelerating.


It might not be that hard of a jerk if the trans engauged before 750~1000rpm. What do you suppose an external pump would draw? 

What would be ideal is upshifts based off motor current. When the current drops below a set point it would upshift one gear until the current drops below that point again for the next gear. Could work well for a series wound motor.


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## FastbackToTheFuture (Aug 1, 2008)

I am new to automatic transmissions and EV conversion. It's my luck that I chose an automatic to convert to EV. It's also my luck that I found such a fine group of contributors as this one. I am sure there will be other people like myself who have had no other choice than to convert a car with automatic transmission. It is an excellent learning experience. I look forward to sharing what I have with this group.

Todd


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## rankhornjp (Nov 26, 2007)

It seems like to me that the biggest problem with this is that there is no pressure in the system unless the pump is turning. I have found a possible solution to this. This is called an "oil pre-charger", designed for an ICE to eliminate dry starting. It is a solenoid controlled canister that is pressurize by the oil pump while the engine is running and holds 160cc of fluid (at 65psi). When you get ready to start the engine, you push a button and the solenoid opens and allows the pressurized fluid into the engine building oil pressure and eliminating the dry start. 

I think you can use this to pressurize the transmission (is 65psi is enough to operate the clutches/bands?), before you press the go pedal and eliminate the jerk when starting off. Here is a link to one made by Amsoil:

http://www.amsoil.com/StoreFront/amk.aspx


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## morvolts (Jun 19, 2008)

rankhornjp said:


> It seems like to me that the biggest problem with this is that there is no pressure in the system unless the pump is turning. I have found a possible solution to this. This is called an "oil pre-charger", designed for an ICE to eliminate dry starting. It is a solenoid controlled canister that is pressurize by the oil pump while the engine is running and holds 160cc of fluid (at 65psi). When you get ready to start the engine, you push a button and the solenoid opens and allows the pressurized fluid into the engine building oil pressure and eliminating the dry start.
> 
> 
> 
> ...


I had also given the accumulator some thought but figured that it wouldnt work unless you reenergized the solenoid everytime you initiated a start at a stop light or when ever the motor wasnt turning.This was the reason I came up with the pump which would be needed only when the motor isnt turning.
A Zero speed sensor would work for that.

I dont know if 65PSI is enough as most trans operate at 150psi+


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## TheSGC (Nov 15, 2007)

I am not sure if an external pump will solve this, but at least in my car, It won't come out of park unless the tranny is spinning. It was a real pain to move the car with the engine out but I figured out that I could insert the key into a slot next to the shifter and then change to neutral and then put the key into the ignition to unlock the wheel.


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## morvolts (Jun 19, 2008)

TheSGC said:


> I am not sure if an external pump will solve this, but at least in my car, It won't come out of park unless the tranny is spinning. It was a real pain to move the car with the engine out but I figured out that I could insert the key into a slot next to the shifter and then change to neutral and then put the key into the ignition to unlock the wheel.



I dont know what your application is but all the modern cars have an interlock that will prevent accidental shifting by small children.
This is accomplished by a solenoid that engages when the brake pedal is pushed and the key is on.
Try this the next time you want to take it out of park,Im guessing the flywheel doesnt need to be turning.


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## TheSGC (Nov 15, 2007)

morvolts said:


> I dont know what your application is but all the modern cars have an interlock that will prevent accidental shifting by small children.
> This is accomplished by a solenoid that engages when the brake pedal is pushed and the key is on.
> Try this the next time you want to take it out of park,Im guessing the flywheel doesnt need to be turning.


I didn't have the AUX battery connected, so that might be it. (I don't have my gas tank out yet, the engine is, and if I turn on the car without it out, it will spew gas every where.)


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## morvolts (Jun 19, 2008)

Pull the fuses marked ECM and FuelPump


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## rankhornjp (Nov 26, 2007)

morvolts said:


> I had also given the accumulator some thought but figured that it wouldnt work unless you reenergized the solenoid everytime you initiated a start at a stop light or when ever the motor wasnt turning.This was the reason I came up with the pump which would be needed only when the motor isnt turning.
> A Zero speed sensor would work for that.
> 
> I dont know if 65PSI is enough as most trans operate at 150psi+


Thats true, you would have to have a button mounted to where you could push it right before you took off to open the solenoid and allow the fluid to pressurize the system. Or design a limit switch operated off the go pedal that would active the solenoid in the first little bit of pedal travel and then turn off the solenoid when you push the pedal some more.

You could probably build a tank that would withstand the extra pressure needed. Just have a tank that would hold 3-4qts of fluid and be able to withstand the pressure, then mount a solenoid operated check-valve, so that when power was OFF it would allow fluid IN the tank but not OUT. When power is ON it would allow fluid OUT of the tank. Then the transmission would charge the tank while driving and it would be ready to use when you come to a stop.


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## morvolts (Jun 19, 2008)

I went to visit a friend who owns a trans shop and really knows his way around the inside of one.
He said that the coupling of the input shaft and the pump drive/converter shaft will work fine.
yes there will be a short lag until the pressure is built up and upon deceleration the trans will lose pressure and free wheel. 
This may be a plus as a manual trans wont free wheel.
We also discussed operation in a long downhill grade and he agreed that it will starve for lubrication when subjected to this.
We also agreed that if that was the case the circulation pump I mentioned before would solve that problem.Possibly a cheap solution to this would be an aftermarket electric fuel pump or an electric PS pump.
Im still not convinced that an auto trans isnt plausible.


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## JRP3 (Mar 7, 2008)

I think this thread shows an automatic is very plausible. At the simplest all you need to do is idle the motor if necessary, or explore the other options discussed.


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## lazzer408 (May 18, 2008)

Why do you insist on idling the motor? Isn't it much easier to learn to press the pedal just a bit till you feel the trans engauge then mash it? Seems like an easy thing to learn to avoid the enegry loss 'idling' an electric motor just to avoid a slight bump during engaugement.


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## JRP3 (Mar 7, 2008)

lazzer408 said:


> Why do you insist on idling the motor? Isn't it much easier to learn to press the pedal just a bit till you feel the trans engauge then mash it? Seems like an easy thing to learn to avoid the enegry loss 'idling' an electric motor just to avoid a slight bump during engaugement.


Sure if that's all it ends up being, I have no problem with that. I just don't know how the trans will behave, how long the lag will be, how hard the bump will be, etc. However, idling the motor makes it "idiot proof" in case you are not the only driver, and how much energy would it actually take to rotate the motor at low speed to keep the trans pressure up? I really don't know if it's a significant amount. Not to mention an idling motor keeps A/C going if you are running it off of the front motor shaft.
Maybe you could set it up to idle the motor when you want to, independent of the "gas" pedal, in case someone else needs to drive the vehicle.


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## lazzer408 (May 18, 2008)

JRP3 said:


> Sure if that's all it ends up being, I have no problem with that. I just don't know how the trans will behave, how long the lag will be, how hard the bump will be, etc. However, idling the motor makes it "idiot proof" in case you are not the only driver, and how much energy would it actually take to rotate the motor at low speed to keep the trans pressure up? I really don't know if it's a significant amount. Not to mention an idling motor keeps A/C going if you are running it off of the front motor shaft.
> Maybe you could set it up to idle the motor when you want to, independent of the "gas" pedal, in case someone else needs to drive the vehicle.


I think you'll be suprised just how fast it is. Shouldn't be more then 1 second. 'corse this is an eternity to the car behind you when the light turns green.


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## Jim (Jun 1, 2008)

As another possible solution, hows this? Place a small acceleration delay/limiter in line between the speed signal from the pedal and the controller. 

This could be as simple as a small programable relay that would only allow a "slow" or marginal ramping signal to be passed to the controller for the time it takes for the tranny to build up pressure. It would of course only do this if the motor has been off for x number of seconds or if you want to get techincal, have a pressure sensor in the tranny send a signal to the programable relay. This way it will always have the "slow start" anytime the pressure is down.

They make these little programable relays to opperate on 12 vdc and can be bought new for around $150-$200. And who knows, since they typically have 8 inputs and 4 outputs, you could probably set them up for other "neat" things around the car. I've used the Schneider and Muller brands and both seem easy to use.


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## lazzer408 (May 18, 2008)

Jim said:


> As another possible solution, hows this? Place a small acceleration delay/limiter in line between the speed signal from the pedal and the controller.


I suggested this some time back. Some if not all controllers have some sort of throttle ramp that is adjustable. If not, yes you could make a circuit to go inline with the throttle signal to ramp it.


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## TheSGC (Nov 15, 2007)

I just have to add another thing about my autotranny adventure-

KEEP all of your engine parts until the car is driving! I haven't gotten rid of any of the ICE components and I am glad. I went to do a test run and the motor revved up and everything was going fine, I threw it into gear and NOTHING happened. 

The transmission computer automatically disengaged the gears. The only two sensors I removed were the Coolant and the Throttle Position sensors. Well, apparently the TPS is like the God of Automatic Transmissions, and when busted (or missing) will no do anything but sit there is neutral. Tomorrow I will plug the TPS back in and see what that does. According to the factory manual, the TPS is a potentiometer that must show at least 0.45 volts to let the transmission engage into 1st gear, on a 0-5 volt scale.


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## OHM (Jun 30, 2008)

Im a bit late on this thread but the following comments are important to reflect on.....



JPG said:


> http://www.poormansev.com
> Is run by a fellow who runs a powerglide in his 64 Chevelle racecar EV. The Auto transmissions will pump up near immediately and will hold pressure at the starting line even with the motor stopped. He's running 13 second quarter miles so I don't really think the auto is making his car slow.
> That said I still like sticks better  The problem is in racing it is easy to miss a shift/break parts while shifting a stick.
> JPG





Coley said:


> He is running a 2 speed, non automatic box. I did the same thing with a cast iron glide back in the early '60s at Cordova Drag Way.
> The only real difference, between a stick and this modified box is the shift, that he is still making manually. It is just easier than a real stick, because it is hard to miss a shift when the heat is on.
> Still not an "automatic" transmission.....


Manual shifting or not, isnt not using a clutch at least considered clutch-less manual or in this case a fully manualized automatic?.


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## Coley (Jul 26, 2007)

My statement is very correct....

"in this case a fully manualized automatic?." ?????

You can't have it both ways. It is either an automatic gift trans or a manual 
shift trans.

Nothing automatic about it.....(case doesn't count)....


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## OHM (Jun 30, 2008)

Coley said:


> My statement is very correct....
> 
> "in this case a fully manualized automatic?." ?????
> 
> ...


If its correct why is the title about using automatic gearboxes?
Poormans EV is using a powerglide which is an automatic box not a manual. 
whether its shifted manually of not its structurally and technically an automatic period.
We need in most cases a 2 speed box and this is a great option. In the many 2 speed boxed vehicles Ive owned
I rarely left them in Drive I enjoy the L and H gears according to the conditions encountered in my commute.

Also its much lighter than any manual box just look at what is left, It would be great if someone cast a new
case and got rid of all the redundant castings.


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## Coley (Jul 26, 2007)

We don't use clutches in a lot of our EVs.... doesn't make them an automatic.

The topic was started about fully automatic, non gutted transmisions, that are more of a job to adapt to REV use and still have them be fully AUTOMATIC!!

Stop trying to split hairs. 

You are still shifting the trans by hand, not as it was intended.

And shifting an automatic is just plain stupid. I rode with a guy that puts his 350 hydro in neutral at every stop, then shifted it by hand through all 3 gears. DUMB....IMHO

Claimed the trans will last longer that way....dumb again....IMHO


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## Racetrack (Oct 27, 2008)

I have given a lot of thought to transmissions in EV's and have concluded that the best performance could be had using a modified Automatic Transmission, or Transaxle. 

The most obvious dissadvantage of an automatic is the less than ideal efficiency. This is due mainly to the use of a torque converter, which is only necessary for ICE's that have to idle. There are some kits out there for eliminating the torque converter for dirt racers. This would be the easiest way to go with your electric motor. Losing the torque converter also gets rid of a lot of weight.

The second problem will be the lack of hydraulic pressure to operate bands and clutches in the automatic when the motor isn't turning. GM has an automatic transaxle designed for hybrids which has an auxiliarly electric pump on the side of the transaxle, which can be powered when the vehicle is stopped but "in gear" with your foot off the brake. This will give you "normal" drivablility--no need to give the wife lessons on how to sneek up on the accelerator so as not to make a big "thunk", sort of the equivilent of dropping the clutch on a manual transmission. I haven't delved into the internals of the "normal" transaxle in my vehicle, but I wouldn't be surprised if it was possible to retro-fit an auxilliary pump.

Shift points on Modern Automatics are controled by either the engine management system (controls fuel injection, ignition, etc.) or a separate transmission computer. There are specialists who can reprogram these systems to your specs. There are also after-market controlers available which are fully programable so you can "do-it-yourself". 

With these little details out of the way, your modified automatic transaxle has the virtue of being just as efficient as a manual, except for the small power drain for the short time the auxilary pump is energized. It can give you very fast shifts without risk of doing nasty things to your manual gear box, and the standard gear ratios lend themselves very nicely to motors with maximum speeds of 5000 or 8000 rpm.

One other plus for the auto transaxle in the efficiency department: There are no hypoid gears in a separate rear axle, necessary to convert the rotation of a logitudinally mounted motor 90 degrees to turn the wheels. These gears run in very heavy oil--usually 80 or 90 viscosity hypoid or gear lube--which has got to soak up a lot of power before it gets to the wheels. The Auto transaxle's gears all run in the light automatic transmission fluid.

Good luck with your project.


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## TheSGC (Nov 15, 2007)

For an external pump, it's a lot easier than one would think. I actually have to thank a ICE dealer for thinking of this: RV Towing package, like the REMCO. It's a pump that is put on your transmission lines so you can put the automatic in neutral and have it towed behind an RV without killing the transmission or engine. 

I finally got my autotranny functioning (it helps if you put the darn fuse back in). Next weekend I hope to get everything reinstalled and figure out how many gears it's working in and if I have to fool any other sensors. I put an OBDII scanner to it and found only two codes, P0118 and P1509. One has to do with Engine Coolant Temp and then Other is the idle control system.


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## JRP3 (Mar 7, 2008)

Coley said:


> We don't use clutches in a lot of our EVs.... doesn't make them an automatic.
> 
> The topic was started about fully automatic, non gutted transmisions, that are more of a job to adapt to REV use and still have them be fully AUTOMATIC!!
> 
> ...


So when I occasionally manually shift my automatic transmission it magically transforms into a manual? Of course not, it's an automatic transmission being manually shifted, which they are all designed to do. Sometimes there are good reasons to override the preset shift points in an automatic and choose your own. I'm afraid you are the one splitting hairs.


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## OHM (Jun 30, 2008)

Coley said:


> We don't use clutches in a lot of our EVs.... doesn't make them an automatic.


Obviously, but some have proved that using an automatic box instead of a manual seems like a better and overlooked option.



Coley said:


> The topic was started about fully automatic, non gutted transmisions, that are more of a job to adapt to REV use and still have them be fully AUTOMATIC!!


Who made the rules of non gutted? read the title again
*The Reasons why Automatic Gearboxes Won't Work with EV's*
If modified they will work, if not modified they will still work with a pump motor. Get it yet?

"Those who say it cannot be done should not interrupt those who are 
doing it." - chinese proverb



Coley said:


> Stop trying to split hairs.
> You are still shifting the trans by hand, not as it was intended.


Exactly so what if its not as GM or some big corporation intended? We are looking at the best for our EVs not just to knock things down and say they are dumb and stupid. If an auto is modified for an individuals need why not? Sounds like a better option than grinding gears/slow changes! 



Coley said:


> And shifting an automatic is just plain stupid.


 Says who? Thats not what its about. As pointed out its a fact that there are more autos out there and we are trying to find a way to use them. You sound like you shouldnt experiment with anything and just leave it as intended.


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## Racetrack (Oct 27, 2008)

Hello, TheSGC,

Does just putting a pump in the transmission cooling lines produce the pressure to operate the servo's (clutches and bands) in the transmission? 

From your explanation that this is done for towing, makes me think it is just for cooling the slipping clutches and bands while being towed.

I think for our purposes, the pump needs to put pressure into the main gallery where the stock pump discharges.


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## TheSGC (Nov 15, 2007)

Racetrack said:


> Hello, TheSGC,
> 
> Does just putting a pump in the transmission cooling lines produce the pressure to operate the servo's (clutches and bands) in the transmission?
> 
> ...


That's a good question. I'll have to talk to the Honda mechanic again sometime and figure that out. Or do an intensive google search. For now I have been feather footing the throttle until the pressure builds up and engages into gear, then giving it more juice. Of course I have to hold the E-Brake when on hills waiting for the pressure to build, but I don't mind.


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## 1clue (Jul 21, 2008)

I've been trying to stay quiet on this thread, but I can't take it anymore.

Is this modification on the WIKI in some way I can't find?

There have been several times I've been tempted to write something up for the WIKI, but I don't have a conversion under my belt so I would be essentially writing fiction, which is fine if it's advertised that way but not if it's not. If you get that.  In other words, I don't want to get above myself here. I would be willing to write something up as long as I have a few actual builders read it over before it goes on the official WIKI.

IMHO, there are a whole lot of automatics out there, so rejecting a car because it has an auto cuts your choices in half. If there are problems with this modification, then they can be posted on the WIKI so that the builder can make his/her own decision.


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## Racetrack (Oct 27, 2008)

Hi guys, 
I don't have a conversion under my belt either, just a lot of research and some experience in modifying an old FMX automatic transmission--not an electric conversion. The automatic transaxle that I refered to in my original post is a GM model,*4T45 (ME7) Hybrid with Aux Oil Pump. *

You can probably Google that and get a picture of it. It just looks like a regular GM front drive transaxle with a pump and extra plumbing on it.

Cheers


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## TheSGC (Nov 15, 2007)

1clue said:


> I've been trying to stay quiet on this thread, but I can't take it anymore.
> 
> Is this modification on the WIKI in some way I can't find?
> 
> ...



There is a thing I wrote in the Wiki about automatics, but I am going to be updating it when my EV is done and I have more exact info on using the ECU/PCMs.


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## TheSGC (Nov 15, 2007)

I finally have my EV somewhat road worthy and I have done some testing and found that I am going to adjust my transmission computer into different shift times. As of right now it shifts as the following:
1st up to 11 MPH
2nd at 11 MPH
3rd at 22 MPH
Yet to try 4th.

It seems to shift at 1800-2000 RPM depending on how hard I hit the pedal.

I have been using D2 for now and it works fine when driving 30+ MPH, but when I hit lower than that the RPMs are too low to properly cool the tiny motor. So not only I am adding a blower cooler, I am going to fool the computer into shifting from 1st to second at 22 MPH. I am going to do this by fooling the VSS (Vehicle Speed Sensor) input by either using a resistor, or make a module that will use PWM to change the 0-5 volt input. It already used a PWM system, so using a PIC's A/D to read the VSS and skewing it to what I want the transmission to see.


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## FPV_GTp (Mar 25, 2008)

Coley said:


> Quote:
> "Also the BACK PUMP on the automatic transmission shaft is a governor on the older style transmissions i.e powerglide , T350 , T400 , T700 (OD) , C4 , C10 , C6 , FMX and so on"
> 
> Wrong....the pump is not a governor.....it is just the main pump for highway speeds. The gov is a seperate item that has it's own job.
> ...


 
Coley , sorry did I miss something ?

or maybe you didn't understand what I wrote

I have made several clutched automatics in my drag cars total removing the stall convert from the automatic transmissions.

All I was saying a automatic transmission can be used in a EV application with some thought and planning.

cheers


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## Racetrack (Oct 27, 2008)

Hello SGC,
Congratulations


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## epyon (Mar 20, 2008)

So , theSGC did you see the power loss in the automatic or was that just a wise tale like the one guy said a few pages back ? I kind of thought the automatic would'nt take the power away like everybody said it would , but the manual from a dead stop would bleed it's amps dry . Granted , I'm using direct drive for my car when I do it . But I'm going for top speed and show and will have a loss in milege .


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## TheSGC (Nov 15, 2007)

epyon said:


> So , theSGC did you see the power loss in the automatic or was that just a wise tale like the one guy said a few pages back ? I kind of thought the automatic would'nt take the power away like everybody said it would , but the manual from a dead stop would bleed it's amps dry . Granted , I'm using direct drive for my car when I do it . But I'm going for top speed and show and will have a loss in milege .


I have not seen any power loss at all yet. The only thing that is somewhat different than driving a stick is the slow start I have to do when changing from forward to reverse or back again. I have to let the tranny pump up for a second and then it will change gears. But once I am in the forward gears, it runs fine. I have pulled about 180 AMPs from the batteries when accerlating and see 40-50 AMPS when cruising at 30 MPH. 

I am working on adjusting the shift points from 1800 RPM to 3100 RPM so I can use first gear for longer than 11 MPH. I want first gear usage up to 22 MPH to keep motor RPM high since I do a lot of 20MPH and below driving because of school zones and traffic. My motor would probably be awful in a manual transmission vehicle because of the gear ratios, but if I can fool the tranny properly, it should work like a charm in the 4 speed auto, and would most likely only see two, maybe three gears.


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## piotrsko (Dec 9, 2007)

SGC How about re-calibrating the tire diameter vss value to something different, like twice the current value up to the limits? should make the tranny shift at 22 mph since the computer would think the tires were smaller. This should mess up the speedo also by 2X, but that is fixable.


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## morvolts (Jun 19, 2008)

TheSGC said:


> For an external pump, it's a lot easier than one would think. I actually have to thank a ICE dealer for thinking of this: RV Towing package, like the REMCO. It's a pump that is put on your transmission lines so you can put the automatic in neutral and have it towed behind an RV without killing the transmission or engine.
> 
> I finally got my autotranny functioning (it helps if you put the darn fuse back in). Next weekend I hope to get everything reinstalled and figure out how many gears it's working in and if I have to fool any other sensors. I put an OBDII scanner to it and found only two codes, P0118 and P1509. One has to do with Engine Coolant Temp and then Other is the idle control system.


See my post 234 regarding the RV pump


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## morvolts (Jun 19, 2008)

TheSGC said:


> I finally have my EV somewhat road worthy and I have done some testing and found that I am going to adjust my transmission computer into different shift times. As of right now it shifts as the following:
> 1st up to 11 MPH
> 2nd at 11 MPH
> 3rd at 22 MPH
> ...


I have such a device already.
Its used for calibrating electronic speedos.
I think the range is +- 200%.


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## Caddyfanatic2 (Mar 12, 2009)

Hello,

My name is Elijah, and I am a DIY mechanic, I guess you would say... 24 years old... And I am really wanting to make an electric car. I know what everyone will say... Because its a 73 Cadillac Deville - that I chopped into a convertible... I dont care how heavy it is, as long as i get 40 or so MI distance out of it I am happy. But its a Cadillac, so I need to keep it an auto. Now, that brings me to this issue you were all discussing. I was originally going to go with the torque converter loss, but i feel that this car is too heavy to have any loss! so I'm playing with the idea of an external pump.

I know that there is a external port after the pump to connect a gauge to measure the trans pressure for diagnostics. I am going to try several methods to supply different PSI's of fluid to this and see if it engages the bands. The local trans shop guys thought I was nuts... but from looking at the schematics and whatnot, it seems like it can be done & fairly easy too.

Wish me luck, When it warms up I'm going to start tinkering. (I live in MO)


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## Racetrack (Oct 27, 2008)

Hello Elijah,

Sounds like you are on the right track to me.

Cheers,

Racetrack


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## Caddyfanatic2 (Mar 12, 2009)

*Hello! Ok so i have been real busy latley with two jobs and all, BUT I was bored and managed to make a little headway on my idea here! Check out what I ran across while doing research! Important part is in bold. Except the whole article was cool, So i included everything.*

_How to work with and modify the turbo 400 hydra-matic 400 transmission by _
_Ron Sessions_

_Pumping losses and viscous drag_

_When it comes to smaller-engined, Lighter vehicles in the more _
_experimental drag racing classes, some of the full-race modifications may _
_surprise you. Larry Smith of All Automatic in Tuscon, Arizona, makes the _
_following modifications to Turbo 400s installed behind engines developing _
_300 hp or less and weighing 3000lbs or less._
_First, he uses the front-pump body from '67-and-earlier models with _
_thin, 0.625-in.-thick gears. Why? Because the thinner gears take less _
_horsepower to turn._
_Next he replaces the pressure regulator spring with a tired one out _
_of a high mileage unit. With the weaker spring, line pressure drops from _
_about 110 psi to about 85 psi. High pressure is hard on seal rings and lips _
_seals, and causes pumping losses that eat up power. To compensate for the pressure drop, he opens up the second and third gear apply oil passages to get more oil to these dynamically shifted clutches faster._
_Last, He only uses three frictions in the direct clutch. This _
_substancially reduces viscous drag, because plate to plate clearence is _
_increased. To keep total clutch stack clearence within specifications, he _
_uses the thick, 375 direct clutch piston._
*Other, More innovative methods have been tried to reduce horsepower **drain at the front pump. A few years ago, a racer replaced the front pump **with a crankshaft-belt-driven power steering pump arrangment. With this **semi dry sump system, the case was tapped, and high pressure, steel braided hose carried the fluid to and from the pump. However it was later **determined that the horsepoweer drain at the crank pulley was as great as that at the front pump, resulting in zero gain.**More recently, racers have tried replacing the front pump with a **low draw electric pump. Combined with an external oil source, this has **proven more satisfactory at reducing pumping losses.*
_Another recent development has been the use of a solenoid to _
_control line pressure. With the solenoid, Line pressure can be kept high _
_untill the 2-3 shift occurs, then reduced once direct clutch lockup has _
_been completed. Archie Beattie at ATI says this modification alone is often __good for 1/10 second in a car running the quarter-mail in 9 seconds or __less._

*So more or less I believe I am on the right track!  We shall see!*


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## JRP3 (Mar 7, 2008)

You might also be interested in this thread: http://www.diyelectriccar.com/forum...s-why-automatic-gearboxes-work-evs-29101.html


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## fugdabug (Jul 14, 2008)

I was thinking much the same (i think...) along the lines of a controller, a pressure switch, inline such that the line to or from the pump senses a set pressure minimum/maximum and activates or deactives the pump,.. thus 'automating' the process and eliminating guesswork. I think the who thing with the Torque Converter removal could be accomplished with something akin to this (maybe a small reservoir could be incorporated for proper hydraulic function). Afterall that is where the greatest amount of inefficiency is to be found in an automatic tranny. (at least that is what I remember...),.. however I gotta 'stick' for the present time with a stand-by stick-shift.


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## Racetrack (Oct 27, 2008)

Instead of having an auxiliary pump, part of an automated starting procedure--after you first turn the key on--could be for your main traction motor to spin up just long enough to charge a hydraulic accumulator--tapped into the high pressure gallerie through the plug hole in the transmission case used for testing pressure. Your low threshold pressure sensor would have to be calling for pressure as well. The accumulator would have to hold enough volume to maintain pressure through several manual shifts from Drive to Neutral to Reverse.

This, of course could only be allowed to happen with the transmission in Park or Neutral--a starter interlock, just like on any IC engine/transmission setup--and would take only a second or two. From there on, a healthy transmission would hold plenty of pressure with the help of a small accumulator. This would keep the transmission clutches engaged with the motor not turning while stopped in gear, waiting for lights, etc.

A second safety interlock would not allow the transmission to be shifted into drive or park without minimum pressure in the accumulator.

Maintaining this pressure while stopped is important. For a nasty sample of what driving from a stand still with no line pressure is like, try by-passing the neutral safety switch on your automatic transmission, put it in gear and then start the engine--makes quite a violent bang, and can't be good for the transmission or any other part of the power train--*THIS IS DANGEROUS AND* *COULD EVEN BREAK SOMETHING.* *WARNING! MAKE SURE YOU HAVE A FOOT ON THE BREAK AND NOTHING IN FRONT OR BEHIND YOU TO HIT!!! On second thought, don't do it. Take my word for it. Clutch engagement is violent.*

The other strategy, already mention, would be to have a pressure switch and separate electric pump--probably a bit more expensive and more weight, but maybe more reliable with a worn transmission. I believe some GM hybrids come with transaxles equiped with just such a pump.

Cheers,

Racetrack


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## fugdabug (Jul 14, 2008)

Racetrack said:


> Instead of having an auxiliary pump, part of an automated starting procedure--after you first turn the key on--could be for your main traction motor to spin up just long enough to charge a hydraulic accumulator--tapped into the high pressure gallerie through the plug hole in the transmission case used for testing pressure. Your low threshold pressure sensor would have to be calling for pressure as well. The accumulator would have to hold enough volume to maintain pressure through several manual shifts from Drive to Neutral to Reverse.
> 
> This, of course could only be allowed to happen with the transmission in Park or Neutral--a starter interlock, just like on any IC engine/transmission setup--and would take only a second or two. From there on, a healthy transmission would hold plenty of pressure with the help of a small accumulator. This would keep the transmission clutches engaged with the motor not turning while stopped in gear, waiting for lights, etc.
> 
> ...


Wow nice explanation of workable implementation. I kinda figured the fluid would have to be 'live', otherwise you have a number of valves in the wrong place at the wrong time (unpressurized). Wow! Again, thanks for that.


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## Jimdear2 (Oct 12, 2008)

Racetrack said:


> Instead of having an auxiliary pump, part of an automated starting procedure--after you first turn the key on--could be for your main traction motor to spin up just long enough to charge a hydraulic accumulator--tapped into the high pressure gallerie through the plug hole in the transmission case used for testing pressure. Your low threshold pressure sensor would have to be calling for pressure as well. The accumulator would have to hold enough volume to maintain pressure through several manual shifts from Drive to Neutral to Reverse.


Racetrack 
Many automatic transmissions are very sensitive to fluid level. Adding a 1 or 2 quart accumulator to the system would make it very difficult to maintain control of fluid level, e.g. level too low when accumulator charged, level too high when accumulator discharged. In many automatics a 1 quart overfill can cause severe foaming leading to trans damage.




Racetrack said:


> The other strategy, already mention, would be to have a pressure switch and separate electric pump--probably a bit more expensive and more weight, but maybe more reliable with a worn transmission. I believe some GM hybrids come with transaxles equiped with just such a pump.


Racetrack,

THe electric boost pump would be the best overall way to make either a converterless or a converter included automatic work seamlessly with an electric motor drive. The OEM engineers chose it over an accumulator for reasons that are pretty obvious.

One reason that I've heard DIYers seem to favor an accumulator was less energy consumption. Think about it, where does the energy come from to charge that accumulator?

Just some thoughts.


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## E DAKOTA (Mar 13, 2009)

I have had good results with a toyota p/s pump, with ports tapped into the front pump and a check valve in the pressure side. I am running th350 converterless setup. also have a pressure switch on the mainline port, set on at 45 & off at 55 psi.

I used B&M's govonor springs to raise shift points.


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## Racetrack (Oct 27, 2008)

Jimdear2

A really good point about the accumulator idea causing problems with excessive changes in fluid level . I hadn't considered that. At the end of the day, I agree that an electric pump running on demand is the best way to go.

Racetrack


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## Caddyfanatic2 (Mar 12, 2009)

Wow, Ok, It may have been cold here, But I couldn't help it I Had to get out there and play with my auto Th400. I rounded up a bunch of parts and got a plan laid out.

Ok I have an old compressor motor that will drive the PS pump. I have no idea how to regulate speed yet though.

And I have decided against using the test port, I figured that I could just run the trans on its own individual motor, so that line pressure is always ideal.

i am doing away with the torque Convertor & Making a straight adaptor.

So I am going to put two line ports in the front pump. I have already checked everything out and it seems like there shouldn't be a problem.

I am going to epoxy the whole Pump part, & have it machined at the machine shop before i put it back together. that way instead of pumping it will act like a wall & the PS pump will take over the pumping duty Wish me luck & here is some pics.

If you have any insight, or Questions feel free to ask.

http://c1.ac-images.myspacecdn.com/images02/92/l_f46ef504446944a2ae7b9ee46c1bb4fc.jpg
lol, oops, I meant to put for high pressure and low pressure hose on the image. Cuz one is high, other is low  I'm tired so give me a break. 

Let me know if you cant see the images. THANKS!


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## Jimdear2 (Oct 12, 2008)

Everyone following this thread needs to do a bit of research in some of the other sections of this site.

In the Technical Discussions section go to the Why Automatics WILL Work in EVs. In the EV Conversions section ,go to Powerglide Secrets Evers Should know.

You will find that 95% if the questions and concerns you've all expressed have been solved or answered.

With automatics just like the stickshift guys, there is, other then the concerns of which vehicle to use as a donor, one major decision to make. 

With or without converter.

Each way has pluses and minuses . . . just tike the clutch desicion.

There are already pre made couplers/adspters for some transmissions or you can make your own.

This huge concern about efficiency is so much bushwa. Anybody who buys an ICE automatic knows in advance it's not as efficient as a stick. They are willing to pay that penalty for the convenience. The same point holds true for an EV.

YOU JUST PLAN FOR/AROUND IT

If you need/want the range and efficiency you have no choice . . . stickshift (maybe). If you want the convenience you can go automatic. A lot easier to get the other half interested in EVs if it is something she will enjoy driving.

With a torque converter, smaller more efficient high rpm motors can be used. One thing about converters no one in this thread seems to have mentioned is they not only allow an ICE to idle at stops, they also multiply torque, up to 250%. Think about how that could be used with small high voltage motors.

There is a whole new world for DIY EVers to work with. Some of them are already doing it.

My thoughts for whatever they are worth.


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## Racetrack (Oct 27, 2008)

This huge concern about efficiency is so much bushwa. Anybody who buys an ICE automatic knows in advance it's not as efficient as a stick. They are willing to pay that penalty for the convenience. The same point holds true for an EV.

YOU JUST PLAN FOR/AROUND IT

Hello Jimdear2 and all,
Some really good points made early in your post regarding the proper use of this group; i.e. use the other threads as a resource and don't re-invent the wheel.

Regarding your efficiency is "Bushwa" comment, sorry, I don't agree. Efficiency is supposed to be what EV's are all about. Since getting the practical range of a DIY EV into the every-day usable range is a primary objective of this whole exercise, efficiency makes some big differences in performance. Translated into Range, picking up 20% efficiency means needing less battery power for a given range, and the reduced weight translates into still more efficiency due to lower rolling resistence and less mass to accelerate, so we now have a better performer, or possibly a smaller motor for the same performance--oops, smaller motor means less weight and guess what? More weight reduction, still higher performance and more range. So, I say again, efficiency is not "bushwa".

Re: torque converters, they are the biggest source of inefficiency in an automatic, the heaviest single component in the transmission, and should be avoided at all costs. The Planetary gear sets in an automatic are very efficient. Torque converters also impose an unnecessary (to an electric motor) flywheel mass, which reduces acceleration (and deceleration) because it takes torque to get them turning and to stop them--torque that does not make it to the drive wheels when accelerating and braking. 

As you have pointed out, it is not hard to eliminate the torque converter and some parts are available for some transmissions off the shelf. Yes, converters provide torque multiplication, but even second gear combined with common rear axel ratios give you plenty of torque multiplication, and of course, traction motors, both AC and DC seem to be capable of generating maximum torque right from zero RPM.

As I have said before on this page, I find Front Drive Transaxles very attractive for EV conversions. One reason is that their final drives are more efficient than hypoid gears in a rear axle. The Second is that since the drive wheels are on the front, regenerative braking can be more robust, since on all cars, even mid-engined super cars, do most of their braking on the front due to weight transfer during braking.

Best of luck to all with your projects,

Racetrack


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## Jimdear2 (Oct 12, 2008)

Racetrack said:


> Regarding your efficiency is "Bushwa" comment, sorry, I don't agree. Efficiency is supposed to be what EV's are all about. Since getting the practical range of a DIY EV into the every-day usable range is a primary objective of this whole exercise, efficiency makes some big differences in performance.


I disagree with you in principle on this point. Range and efficiency are not the be all, end all of building an EV. They are important, but for some people, quiet, comfort, power, just to be different or moral position on envirement are the standards they go by.

What I am trying to say is there are other reasons to make an EV. Every since I joined this forum I have heard efficency banged on as the ONLY reason. IMHO it is not, although "IT IS" important to the future of EVs. But it is only one of the maney things.




Racetrack said:


> Translated into Range, picking up 20% efficiency means needing less battery power for a given range, and the reduced weight translates into still more efficiency due to lower rolling resistence and less mass to accelerate, so we now have a better performer, or possibly a smaller motor for the same performance--oops, smaller motor means less weight and guess what? More weight reduction, still higher performance and more range. So, I say again, efficiency is not "bushwa".
> 
> ]Re: torque converters, they are the biggest source of inefficiency in an automatic, the heaviest single component in the transmission, and should be avoided at all costs. The Planetary gear sets in an automatic are very efficient. Torque converters also impose an unnecessary (to an electric motor) flywheel mass, which reduces acceleration (and deceleration) because it takes torque to get them turning and to stop them--torque that does not make it to the drive wheels when accelerating and braking.


You should review some of my other posts I am a preponent of converterless automatics (see powerglide secrets). It's just that I don't want to close off an entire branch of the power transmitting process just yet. We are still new at this, some genius might turn us all upside down about how to use torque converters.

I pretty much agree with all of the remaining things you find as positive except the stress on efficiency and the single track thinking that there is only one right way to do things that so many people seem to be locked into.


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## Racetrack (Oct 27, 2008)

Hi Jimdear2,

I think is is safe to say we agree on most things. I don't consider myself stuck in any one mode, and yes, it is a mistake not to keep an open mind. My comments were based on what I know now, but everything can change. I think the best that we can do is to put forth ideas and opinions for others to consider and comment on. We are putting a bunch of ideas into a pot and seeing what bubbles to the surface. Let's keep that going.

Re: the quest for efficiency, there are limits to what can be done or should be done. I like my creature comforts too. I, too, keep reminding myself that an amazing idea might come along tomorrow, which will change everything. From what I have seen and learned, one of the advantages of an electric traction motor is that it doesn't need a torque converter.(Sorry, just had to get that in there!)

I think we can all agree on, this is an exciting time to be alive!

Cheers,

Racetrack


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## Jimdear2 (Oct 12, 2008)

Racetrack said:


> Hi Jimdear2,
> 
> I think we can all agree on, this is an exciting time to be alive!
> 
> ...


Racetrack,

Amen brother, amen.

If we can keep from killing ourselves off or giving the country away and if i can make it for ten more years (getting old sucks but it beats the alternitive).

We are going to see some amazing stuff.


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## stevesnj (Apr 13, 2009)

So I have an automatic transmission Miata should I just swap it with a manual? 

Also what does Tesla use? They just press a button for P, D, R. I would love to do that...lol


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## JRP3 (Mar 7, 2008)

I think Tesla uses a single speed gear reduction and electronically reverses the motor.


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## stevesnj (Apr 13, 2009)

JRP3 said:


> I think Tesla uses a single speed gear reduction and electronically reverses the motor.


Found a pic and article on the Tesla 1 speed. Tesla Explains New Transmission

Teslas Tranny Blog with Pics!!


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## Caddyfanatic2 (Mar 12, 2009)

Why, That whole Tesla thing is pretty cool! I like the cutaway of the trans!

Ok, In other news, I hope some people are following my continuing progress on the th-400(electric) Because I am starting to make some decent progress!

I have decided for now I am going to use a 32cc 2 stroke motor that I had laying around to power the transmission for test purposes. It has a built in clutch so I should be able to connect it right to the input shaft & when its idling, its stopped like a electric motor would be. and as I rev it up it begins to spin as the centrifugal clutch engages. I know its not electric, but unfortunatly I have a budget & this is all I have to work with.

I have included a picture of the progress on the front pump so far, I have JB welded the whole pump & now all I have to do is take it to the Machine shop to get it resurfaced so its smooth & then take off the "tangs?" for the pump drive, so that when the torque converter shaft is in there it doesn't try to turn the "now" seized up pump. Plus, I still have to tap & die the holes for the Power Steering pump input & output.

Also I need to come across a gauge that reads up to 300 PSI. So i can measure the internal pressure.


Oh, and when I get a few more bucks I am going to get enough grinder blades so that I can take this torque converter apart & Make it into a solid shaft drive.


lol, If anyone is interested here is a link to my YouTube where I am running that little motor & showing how I can grab that clutch with my hand and hold it still while its idling. I wouldn't dare with it Revved up though! It would probably take me spinning with it!

http://www.youtube.com/watch?v=qnxbdFLyA_Y

Well, Untill next time!
Elijah

Oh and PS, I just wanted to throw out there, but untill its proven I cant say much, I think automatic will be one of the more efficent trans's for a conversion except for the clutchless manuals. If I can get the governors to shift at the proper speed & kickdown working right, it will always keep the trans in the ideal gear! Think about how efficent that would be rather than a manual stuck in 2nd all the time, or pulling up to 20mph in 2nd gear on a hill? this thing will always start in first no matter what automatically. Just hop in and go. Plus if you want a lower gear just drop the selector down one notch. Plus the benefits of park. Seems like a winner to me. Plus Dad, Mom, Girlfriend, Friend visiting out of town can just hop in and pop her in d & go. Much better than trying to school even a veteran of a stick to drive one without a clutch! Eh, but thats just my opinion. 

Later!


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## e-struck (Mar 3, 2009)

I should be posting this under why auto trans will work

I read that you plan to use a power steering pump , You might want to check out a electric in line fuel pump , pressure up to 115psi 12volt ,amps from about 5 to 15 depending on pressure and flow .
The flow charts are at www.inlinefuelpumps.com.
I think when wired in through a pressure switch with the the ign. on and no pressure pump runs with little or no leakdown the pump would only run enough to maintain pressure.

Wayne


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## Racetrack (Oct 27, 2008)

e-struck said:


> I should be posting this under why auto trans will work
> 
> I read that you plan to use a power steering pump , You might want to check out a electric in line fuel pump , pressure up to 115psi 12volt ,amps from about 5 to 15 depending on pressure and flow .
> The flow charts are at www.inlinefuelpumps.com.
> ...


This sounds like a great idea. I was wondering if the transmission could be operated just on the fuel pump. The reason I am asking this is that the mechanical pump in the transmission is the last energy waster, once you have gotten rid of the torque converter. Most (all that I know of) AT's use a pressure relief valve to regulate pressure down stream of the pump. As the RPM's build, a larger and larger volume of transmission fluid is bypassed through the pressure relief valve. The wasted power is proportional to the volume of fluid X the pressure drop (Line Pressure).


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## Telco (Jun 28, 2008)

Caddyfanatic, the TH400 is a fine trans, and is just about the strongest transmission GM ever put out, if not the strongest, and is one of my personal favorites. The only way to kill them is to run them dry. They live behind 1200-1400HP engines. 

But, one must know the bad as well as the good. They are also power hungry due to the size and weight of the internal components. When you replace a TH350 with a TH400, an ICE vehicle can lose up to 20HP (not sure on the exact number) with just that swap. So, while it would be a fine proof of concept tester, I'd think twice about actually using one in a vehicle unless you are building a very high torque EV like a dragster.


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## GKnightBC (Sep 10, 2008)

On the same thread: Has anyone been able to use a variable speed tranny in an EV project? The reason I'm asking is twofold. One is that the VTs have no shifting and no gearing, yet produce great accel for torque at all speeds, and two I may have a line on a wrecked suv with VT for cheap, and I was wondering about the possiblity? 
IMO, having the VT would be a huge step ahead in tranny tech for EV projects!


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## Caddyfanatic2 (Mar 12, 2009)

I just want to say great idea on the fuel pump! I will not be able to test one for awhile, but it might work! Im just afraid of the flow rate.

Yeah, It is a little heavy, But I did manage to pick it up all by myself off the garage floor. I like the idea of STRONG because its going to eventually make its way into my 73 Cadillac Convertible, I'm thinking 2 9" motors. I'm hoping thats enough. I think the end weight of this whole thing will be around 6000lbs. give or take. I am going to buy all the components first and get the batteries last. I'm definatly going lithium.

Do you think dual 9" motors will do it? or do I need more? the original motor in the car is [email protected] [email protected] 

I am determined to make this car electric. I put up a few pictures of it. I am going to paint it dark blue & make a fiberglass removable top for it 

I figured If Neil Young could do it to his LincVolt www.LincVolt.com Even though his is a Series Hybrid I can do it to my Cadillac

Till next time,
Elijah


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## e-struck (Mar 3, 2009)

For the trial and testing, and knowing you don't need to waste a lot of money to try something out these pumps can be found at the recycle yards (pull your own , junk yards) very inexpensivly. They can be found on (Fuel injected), Ford trucks,some series BMW's and not sure of other vechicles.
If concerned about the volumn try 2 in parallel , then if you like the results I am sure a raceing pump is available with the necessary capacity. I personally think one pump will be more than adequate as it's no longer pumping a flow of oil to the torque conv., unless the transmission has a lot of bleed or bypass (wear) . 
Good luck, and keep us posted and keep the pictures cooming .

Wayne


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## JRP3 (Mar 7, 2008)

Anyone worried about the lifespan of a pump designed to pump thin fuel being used to pump thicker trans fluid? On the other hand the lubrication with the trans fluid should be better so maybe it balances out.


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## Racetrack (Oct 27, 2008)

Re: donors for electric fuel injection pumps, you may want to find one that is not mounted in the gas tank these days--most cars, I believe. In tank mounting is how they get their cooling.

Regarding pump longevity, pumping transmission fluid instead of gasoline, I agree that the lubricity of the transmission fluid will certainly be very kind to the internals of the pump. My only concern is that these pumps normally pump cold fuel. Here we will be asking it to pump warm or hot fluid. I expect it will run much cooler without the torque converter (may not even need a cooler) but this is something to experiment with, while keeping a thermometer handy.

This seems promising,
Racetrack


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## Caddyfanatic2 (Mar 12, 2009)

First off, I apologise, But I worked like 14 hours today, I am not thinking too clearly. So excuse my post if it doesn't make too much sense. lol

Well, not exactly sure if this helps at all but, my dad uses a 6psi universal pump to pump diesel fuel from one tank to the other even in 20degree weather. So I would think that viscosity wouldn't be an issue. Nor would Heat, since I believe that the unused fuel in the fuel rail returns to the fuel pump housing after the pressure regulator in most newer cars, also the #1 killer of fuel pumps in NM where I used to live wasn't the heat, It was the sand in the fuel  So I am actually really liking this fuel pump idea, especially because of the real low current draw those pumps have! I havn't been able to doo any pressure tests, but I'm estimating needing quite a large volume though  Although I am pretty sure there are countless different options we havn't even thought about! I'm going to start to think outside of the box for now on. And Thanks A bunch! I definatly came to the right place. Lots of smart people around here.

Later,
Elijah


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## Caddyfanatic2 (Mar 12, 2009)

Well the pump is done, All I have to do is pay for it & get the inserts for the hydraulic hoses put on. I think I can do that myself. Here's the pictures. Left is before machining, Right is after, notice no torque converter drive tangs & the whole pump gear set is filled in. I did get a few small bubbles when I filled in the gear set BUT I dont think they will be an issue.


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## E DAKOTA (Mar 13, 2009)

I have tried the Ford inline fuel injection pump from a ford ranger. it did not have enough volume to hold 15 psi in a TH 350.


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## mcudogs (Apr 29, 2009)

Racetrack said:


> This sounds like a great idea. I was wondering if the transmission could be operated just on the fuel pump. The reason I am asking this is that the mechanical pump in the transmission is the last energy waster, once you have gotten rid of the torque converter. Most (all that I know of) AT's use a pressure relief valve to regulate pressure down stream of the pump. As the RPM's build, a larger and larger volume of transmission fluid is bypassed through the pressure relief valve. The wasted power is proportional to the volume of fluid X the pressure drop (Line Pressure).


It may be that there would be no increase in efficiency from running the transmission from an electric pump, as the power required to pump fluid around the transmission is proportional to the pressure that the pump develops, which would be the same in both cases. THe only difference would be that with the electric pump the amount of fluid moved would be less than the mechanical pump. Taking into account the efficiency of the electric pump 90%? the difference in power required may be marginal.


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## frederic (Jul 4, 2009)

KiwiEV said:


> 1: The RPM range on auto gearboxes is set to work with the RPM range of an ICE engine. An auto gearbox would change gear too soon and too often for an electric motor to be efficient.


Being an auto-enthusiast and a fabricator, you can in fact change the shift points across a very wide range by changing the control plate and "balls" in the plate, which in turn control hydraulic pressure.



KiwiEV said:


> 2: The torque converter would require spinning even while the car is not moving to stop the fluid inside from "resting" at the bottom of the torque converter. This constant spinning wastes more amps.


Yes, that is true, however in an EV vehicle the torque converter can be eliminated entirely because there is no minimum RPM required as is the case with a gas engine. Electric motors can be "instant on".

The transmission can be pressurized by a different (i.e. smaller and more efficient) pump either driven off the main EV motor or a separate, smaller hydraulic pump much in the way an electric log-splitter does. The transmission's ability to shift correctly depends on the pressure applied... which is why a lot of luxuary cars wear out their transmissions faster than other vehicles - the controller code deliberately shifts the transmissions slowly by adjusting the pressure slowly to "mush" the shift so it's less obnoxious to the driver. While this might be comfortable, this is abuse of the mechancals. One only needs a 2 HP electric motor to make enough pressure because the flow required is not that great, if there is no torque converter. On a 120VDC system a 2 HP motor would draw about about 20 amps. Yes, that's a lot, but I would bet that's far less than spinning the main engine that drives the transmission's input shaft.

If one was "highly concerned" about this extra current draw, one could easily put a belt from the massive, main motor to a simple electric clutch off a riding mower to the back of the smaller, 2HP motor and once the main motor reaches a certain RPM (say, 1850 RPM) the 2HP motor's power is cut and the clutch engaged. Holding in a mower PTO clutch draws about 4.5-5.5 amps @ 12-14V, much less than the 2HP motor itself. When the main motor's RPMs drop below the designated RPM for the hydraulic pump, the electric clutch opens and the 2HP motor is powered - maybe this "switch" is done with a speed sensor that drives a boring SPDT relay, switching between the two devices (clutch, motor).

So in my mind, with some clever fabrication and some additional controller effort, one should be able to use an automatic transmission, especially the newer ones that are fully electronic and can be controlled by mosfets - which is how the OEM's do it.

If pressure is maintained by a separate pump and there is no torque converter, you could still use the electric motor for regeneration, by simply "downshifting" the transmission to a lower gear while slowing.


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## frederic (Jul 4, 2009)

Caddyfanatic2 said:


> Do you think dual 9" motors will do it? or do I need more? the original motor in the car is [email protected] [email protected]


Just because the caddy had those specs originally does not mean it has to have those specs once converted to electric, unless of course you are building your project so you can spin the tires endlessly.

At about 6000lbs, that weighs as much as my friend's 81 Dodge D350 crewcab which he is converting to a "hybrid". Since his crewcab has 4wd, the front spool was replaced with a differential and two "Transwarp 11" motors installed on the chassis at about midship between the frame rails on a fabricated subframe. One motor "dead center" facing rearward driving the rear driveshaft and in turn the rear axle, and the other motor mounted next to that one but more towards the driver's side facing forward, approximately lining up with the front differential, and a driveshaft installed between the two.

In a nutshell, this allows the two motors to directly drive the four wheels without axles binding as would normally be the case with truck 4WD systems. Since this vehicle is a "highway hauler" modifying the 4WD in this manner will be fine.

Because the frame is a boring ladder frame and quite long (remember, crewcab!) there are two rows of batteries down the length of the long wheelbase on both sides. I forget how many batteries total but there were many, many of them. The truck has no problem "carrying them" because it is a D350 capable of hauling an additional 4500lbs on it's chassis because it's essentially a commercial truck shaped like a 4-door pickup.

The "hybrid" part is also not very complicated - it's a 4 cylinder honda Vtec with honda engine controller mounted on a subframe to be dropped under the hood, close to the firewall, transversely. Instead of a FWD transmission there will be a massive generator to recharge the batteries as well as provide additional current for hard acceleration if the batteries are not up the task. The subframe is partially together but the generator has not been acquired as of yet so there is much more to do. My friend was recently downsized from his job so spending cash on this project has been temporarily halted.

He chose to mount the batteries down the length of the wheelbase outside the frame rails because that's unused space and doing so centers that weight between the front and rear wheels. This also leaves the bed free for normal pickup truck use - sheet rock, tools, plywood, you know, the usual.

The one advantage his truck has over your Caddy is frame strength - obviously a 350-grade truck has a massive frame and is specifically designed to support much weight. While my friend's is a crewcab pickup, the same frame was used by Dodge to build ambulances, dump trucks, tow trucks, utility trucks and so on.

I shared this with you to give you some ideas as how to convert a land-yacht to electric, even though much of what my friend has done probably won't be directly useful to you. But, maybe you can draw ideas from it.

I am a huge fan of land yachts myself, car and truck. The problem with vehicles of this kind is they take tremendous power to move, as you probably know every time you fill up the tanks now. ;-)


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## coulombKid (Jan 10, 2009)

I've done a little reading up on candidate EV automatics. It looks like the GM 4L65E transmissions would work well without a torque converter. Its all electric and, with 5 planets it has a torque rating of 380 ft.lbs. It came in like 2005 Camaros and Vetts. Being all electric, a programer would be able to integrate its controls with an AC drive to get a really smooth drive train. With a 3.06:1 low and 0.7:1 OD the electric motor can be lighter and faster.


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## few2many (Jun 23, 2009)

Some guys seem to have misconceptions about torque converters. They arent the pump, you wont need a seperate pump or motor to provide hydraulic pressure. The ice spins the whole tc case, that spins the pump in the front of the tranny, providing the hydraulic action. Then, the drive shaft inside the main pump drive is spun by the inside of the tc. 
Also, most auto trannys can be easily converted to full manual operation, that is, the valve body is changed out with one that provides full manual control in all gears. Essentially a clutchless manual with no lag btween shifts that a manual with clutch will have. this will provide engine braking similar to an ice with a clutch. Or, for an ev, regen. Youll need a hollow adapter in place of the tc because the tranny still wants to circulate fluid through there. I would completely agree with using a gm th350, 400, 700r4 or 4l80e as the aftermarket following is great. performance rebuilds can be found for a grand or less(usd). I would advise against messing with port sizes and checkballs, they have shift kits that keep all internals in harmony. About using fuel pumps, the pressure is too low, volume too low and gas is very thin, tranny fluid is way thicker.
http://www.diyelectriccar.com/forums/showthread.php?p=127726#post127726


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## EV-propulsion.com (Jun 1, 2009)

I think this is one of those rumors that went wild...I have been using automatic transmissions since 79 for conversions- I've used fords, chryslers, and now mazda (in my miata conversions) WITHOUT ANY TROUBLE. 

see some pictures at: www.EV-propulsion.com 

Pressure will build almost instantaneous when the motor starts spinning-even low rpm. Did you ever start an ice automatic in gear without a neutral safety switch? The car will move on starter rpm. As far as shift points, if it has a vacuum modulator, just make it adjustable to set your shift points. As far as lockup, I use the Overdrive switch on the shifter for the lockup converter, but generally leave it locked up all the time. Or, any race converter shop can disassemble the conveter and weld it solid inside.
As far as being inefficient, range diffence has been undetectable between my auto and manual conversions-with the converter locked up, the only difference is the pump turning-butmust be equal to that of turning gear oil in the manual trans.
Now the secret is out!


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## few2many (Jun 23, 2009)

I would have to agree fully with ev. Just a question, have you tried no TC and have you tried to idle the motor(i know its not neccessary, just curious if youve tried)


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## DavidDymaxion (Dec 1, 2008)

How about the tranny in the Chevy Suburban hybrid? It has the electric motors built in! You'd have to drive the motors with AC.


coulombKid said:


> I've done a little reading up on candidate EV automatics. It looks like the GM 4L65E transmissions would work well without a torque converter. Its all electric and, with 5 planets it has a torque rating of 380 ft.lbs. It came in like 2005 Camaros and Vetts. Being all electric, a programer would be able to integrate its controls with an AC drive to get a really smooth drive train. With a 3.06:1 low and 0.7:1 OD the electric motor can be lighter and faster.


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## EV-propulsion.com (Jun 1, 2009)

No I never tried without a converter-I have thought about it a while back, but with the lockup it wouldn't be needed-although it would save maybe 50lbs! I may try it on the next one-see if the weight difference makes any difference. I never tried idleing the motor, it _really _isn't necessary
Mike
www.EV-propulsion.com


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## Racetrack (Oct 27, 2008)

EV-propulsion.com said:


> No I never tried without a converter-I have thought about it a while back, but with the lockup it wouldn't be needed-although it would save maybe 50lbs! I may try it on the next one-see if the weight difference makes any difference. I never tried idleing the motor, it _really _isn't necessary
> Mike
> www.EV-propulsion.com


There has been some really good discussion and information here. One thing that I have not seen mentioned as a big plus for losing the TC is the reduction in flywheel mass. 

Many years ago, on my 289ci Ford, I exchanged the old steel flywheel for an aluminum one. The increased throttle response was remarkable. Since electric motors do not have big power pulses to smoothout, there is absolutely no need for any sort of flywheel with an automatic transmission. Manual transmissions, or course, still require some sort of a flywheel to carry the clutch assembly, so chalk up another plus for the AT. Eliminating the Torque converter, which is also a big heavy flywheel, will noticeably improve throttle response in an electric, especially at higher motor RPM's.

Good luck everyone!

Racetrack


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## few2many (Jun 23, 2009)

Thanks Mike, nice to see someone has successfully done it, instead of all the speculation that its a horribly inefficient idea! I have seen cars that have it, but no one has explained theyre build issues, computer control, throttle linkage and so on. I plan on using a gm 700r4, i have one in my jeep and i like it, small, light, overdrive and surprisingly simple for an aod. Unlike my ford superduty aod, hope i never have to open that thing up!


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## EV-propulsion.com (Jun 1, 2009)

I think the 700r4 will not be a problem, personally I have not used one in a conversion. (yet) If I am not mistaken, isn't the shift controlled by a cable? Not a kickdown cable but one for the trans to know the throttle position. (I forgot the name of that cable-was it a TV cable or something?)That eliminated the vacuum modulator-if this is the case, that cable can be set to make your shift points where you want them. Basically it is a manually controlled (as opposed to electronic controlled) transmission so it should work. The only thing that might be bad about it is its weight-I know race people years ago who swapped the 700 for a 200 trans (although they had to make internal mods to equal the strength of the 700) because it was so much lighter, thats if my memory serves me... 
If I am wrong about this trans I am sure someone will correct me!
One last thing, try to keep that jeep as light as possible-everything you have read about weight and EVs is true.....its the enemy!


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## few2many (Jun 23, 2009)

Hey Mike, one of my posts must have been misleading. My 63 wagoneer is not my ev project. It is simply too big, heavy and has a big ugly v8, its simply for weekend wheeling. I was saying i was familliar with this tranny cause Ive wrenched on them. I have yet to pick a donor for an ev, looking for a small, 4 door pickup like a nissan frontier or chevy colorado.


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## Drew (Jul 26, 2009)

If you want to modify control regimes on a newer transmission then this might be what you guys are after.

http://www.powertraincontrolsolutions.com/

I'm not sure of the details of how they work but a colleague of mine who has a fair amount of experience with Auto Trans tuning etc has been intending to use one of these to modify the shift points, shift firmness etc for a vehicle which he's done a powertrain swap for.


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## OHM (Jun 30, 2008)

EV-propulsion.com said:


> I think this is one of those rumors that went wild...I have been using automatic transmissions since 79 for conversions- I've used fords, chryslers, and now mazda (in my miata conversions) WITHOUT ANY TROUBLE.
> 
> see some pictures at: www.EV-propulsion.com
> 
> ...


Does this mean It will need to idle at a certain minimum rpm when you are stationary? 

If so what rpm, if not then even better.

When you say disassemble the converter, weld it solid inside to remove the converter all together and just leave the toothed female shaft to be welded with the input shaft?


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