# 4-5:1 gear ratio trans anyone know?



## booksix (Aug 26, 2008)

I take it you're building a front wheel drive car? If not, the rear end in the car will do a large part of the gearing. With two 9's you should be fine will gearing in the 3-4:1 range (atleast that's what's working for others, mines not done yet


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## Bowser330 (Jun 15, 2008)

RWD...

I was going to go the route of the Tango with 2 motors connected to each of the rear wheels through two reduction gearboxes...but without cheaply available reduction gearboxes (for each wheel) I dont see this happening...

I wonder if i installed two differentials one of the front axle and one in the rear and connected two DC motors if that would be an option...the front of the car would use the suspension from a rear of the donor car but im sure with some modification it would work out fine...

Connect a warp-9" to the rear axle (144V 500A max) and connect a sepex motor (84V 425A max) with Regen to the front axle...

Warp-9" = 1700
Curtis = 1500
Sepex package (motor and controller) = 1400
Cost of one extra "front" differential = ????
Total = 4600

Alternative style:

Siamese style:
Siamiase motor = 5750 
Zilla 1K = 2750 (if you can even get one...)
Total = 8500


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## booksix (Aug 26, 2008)

Two diffs would be great, it'd give you AWD. I've pondered that but it'd be a LOT of work. Suspension geometry can be tricky.

As for two mismatched motors, everything I've read says it's a bad idea. A matched pair would be excellent though, that's what I'm planning now; eventually with 2 controllers


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## madderscience (Jun 28, 2008)

BMW 1600's, 2002's and 320i's and probably others have divorced differential units with gear ratios ranging from 3.9:1 to 4.77:1 depending on the car and its options. The units are fairly compact and have one input flange, and two output flanges so they could fairly easily be adapted to almost anything with independent suspension.

Having had a bmw 1600 that had a 4.77:1 in it, I know that ratio was fairly rare though because all the 2002ers were chasing me around with wrenches wielded.

many older import cars also have rear ends in the 4:1 range.

Good luck.


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## TX_Dj (Jul 25, 2008)

Pair of pullies and a kevlar belt, ala NGV or motorcycle?


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## dogstar74 (Dec 6, 2008)

You may want to check out Metricmind.com His website about the no compromise conversion is about using two different gear ratios for a front and rear drive system to get the best of both worlds in torque ratings. In other words, the front and back are purposely geared differently to get the benefit from the two motors' torque curves. 

I know I'm not essssplaining this very well, so jump over there and give it a read. Also, I'm not sure the nuances of an AC vs DC setup. 

Good luck,
Aaron


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## Bowser330 (Jun 15, 2008)

would the pair of gears/pulleys and a kevlar or chain actually work? is it that simple as machining those pieces and mounting it?


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## TX_Dj (Jul 25, 2008)

Works fine for the millions of vehicles that use that configuration, yes... not even counting the millions of devices like conveyors and such that use the same setup.


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## Jason Lattimer (Dec 27, 2008)

You are over thinking this too much. If you are using a rwd vehicle like I intend to use, you can get drag racing diff. with different ratios. My Ford diff. 7.5 , 8.00 , and 9" rear ends can be bought with or without posi and you can get ratios that go all the way up to 6.00 to 1 in some racing applications. Just thought this info might be of some help. Also, if you have a front driver, a lot of them already have high ratios, my exs Taurus has a ratio of 4.10 to 1 in the front axle.


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## Racetrack (Oct 27, 2008)

The idea of going with a fixed gear ratio for front and rear wheel drives is attractive because of its simplicity. There is a blog detailing an "advanced electric conversion" with a similar approach. This guy found that Toyota had differentials on some of its trucks and sport ut's that could fill the bill.

However, these units are almost as heavy as some of the lighter fwd transaxles. If you don't want to shift gears, you could still use a couple of these and just leave them in the gear which works best for your motors and the speads you will be traveling.

These transaxles using a transverse engine mounting have the virtue of not having hypoid gears, because the motor rotation is already in the same orientation as the half shafts turning the wheels. This saves a lot of weight and improves efficiency in the transaxle, as opposed to hypoid gears which have to turn the rotation 90 degrees, run in very heavy (80 or 90 viscosity) hypoid or gear lubes, and just can't be as efficient as gears running on the same axis.

Now that (maybe?) I have made you think about using a couple of light transaxles wouldn't it be worth working out the clutching and shifting problems in order to make use of all the gears available? There are some real advantages to this:

1. Starting from a stop in 1st gear multiplies motor torque and gives acceleration equal to a fixed gear motor with three to four times the torque. 

2. The motor(s) use(s) a lot less current from you batteries to accelerate if it is kept at rpms closer to its rated power rpm, resulting in much better range.

3. With the gearing in these transaxles, you can get the performance you want with smaller (and cheaper) motors.

Good luck with your project!


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## Bowser330 (Jun 15, 2008)

so essentially have one shifter connected to two shift linkages and making sure it all connects/aligns perfectly, that seems to be do-able..

Another option is using transfer cases from 4x4s and replacing the gears inside to whatever gear is best...

144V 9" FB1 motor (1500$) can be connected to a transfer case that has a 5:1 ratio..., then use one of the half shafts to connect to one rear wheel...Cap off the other half shaft port...make 2 of these setups one for each rear wheel...

144V 1000A max controller (hopefuly no more than 1500$) need two of them...total 6000$ motor+controllers+TCs and gears (1000$ for 2), total 7K$....

FB1 motor at 144V and 1000A = 250ftlbs torque and 100hp.

2 of them side by side in the rear would give, 500 ftlbs and 200 hp...

0-2000rpm(0-25mph at 5:1 ratio) = 500ftlbs (190hp?)
3000rpm (35mph) = 290ftlbs (165hp?)
4500rpm (60) = 100ftlbs (85hp?)

Can we use the horsepower formula?...(Torque X rpm)/5252 = Hp?

5:1 ratio makes FB1 at 144V efficient in a large rev range...
4.5K-6K rpm = 90%+efficient (speeds of about 60 to 70mph) 
6k-8k rpm = 80%+ efficient (speeds of about 70 to 100mph)
3K-4.5K rpm = 80% efficient (speeds of about 35-40 to 60mph)

35mph to 100mph is at least 80% efficient....


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## DaElectric (Jul 26, 2007)

Try looking at the way that the Tropica did it.
http://www.getmsm.com/ev/tropica/default.htm


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## Bowser330 (Jun 15, 2008)

Twin 6.7" motors at 72V, each with its own belt driven reduction gear setup...

hmm...i wonder how two 6.7" motors at 144V would do...

i think making a chain or kevlar belt gear box is entirely possible...probably cheaper than the transfer-case idea...but would take more fabrication skill....

thanks!


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## Racetrack (Oct 27, 2008)

Bowser330 said:


> Twin 6.7" motors at 72V, each with its own belt driven reduction gear setup...
> 
> hmm...i wonder how two 6.7" motors at 144V would do...
> 
> ...


Hello Bowser330
I followed the link for the info on the Tropica last night--fascinating, and a fabulous project for 10 years ago. Unfortunately, following the history of one of these vehicles through a little less than 10,000 miles made it quite apparent that this vehicle was loaded with reliability issues. One of the wheel motors was burned out (I believe) on three occasions. There was also a belt issue with one of the motors, which reminded me that belts, while quiet and light weight, require proper tensioning and maintenance, and are limited in their torque handling.

The whole car appeared to have been built from the ground up, which allowed the builders to design for a huge back bone battery tray which must have weighed more than the rest of the car. Maximum range appeared to be about 20 miles. I was not able to find a price for this vehicle, but considering that it was almost a hand-built vehicle, it must have been pricey.

Given all of the above, plus a huge number of repairs that I have not recounted from the owner's blog, I would run away very fast!!!

Available technologies have improved immensely over the past 11 years, which is, in my opinion, the most practical way to "role your own",as follows:

1. Start with the donor car of your choice.
2. For an every-day driver, use a front wheel transverse drive transaxle with adapters for your motor.
3. Use one of the high voltage (340 volt nominal) AC drive systems--75 HP should give good performance using the stock gearing in the transaxle, which also reduces battery draw on acceleration, thus improving range.
4. Use one of the Li battery systems which are becoming available.
5. Use an ultra capacitor to provide extra current for acceleration and to absorb re-generative braking current. This will reduce wear and tear on your very expensive batteries, extending their service life.

If you want a HOT ROD, which will put most carbon fueled cars to shame, put a second power train in the rear for AWD. Another nice thing about this is it gives you the possibility of balanced regenerative braking, front and rear, and twice the acceleration (or deceleration) without spinning the wheels--especially great in wet weather!

The power train and storage I have listed is pricy, but considering the reliability gained and money saved by eliminating major repairs every 200 miles might even allow you to break even on the dollars.

When (and if) Eestor makes good on its promise of a 52KWHr energy storeage unit that weighs about as much a a full fuel tank and takes about the same amount of space, you can swap out the lithiums and have yourself a 200 mile highway capable cruiser.

If Eestor does come through, you will be able to buy whole electric power train kits from Zenn Motor Company in a couple of years.

I can dream, can't I?

Cheers


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## Bowser330 (Jun 15, 2008)

http://www.tropicaev.org/#sticker

Here is the info for price and components...

From the pictures I've seen the motors were geared on this flimsy looking belt...I think this may have contributed to the burning out and other problems.

A proper chain drive or kevlar belt with plenty of teeth would be used in a setup I would consider...

The link claims a range of 60-80 miles but I am not sure how accurate it is...although the T-125 have about 120AH at a 1HR rating..

the batteries used originally were 12 x 66lb ea. = 792lbs of Trojan T125s

lets not hold our breath for eestor...

the plan you have sounds good..getting a nice AC system that is worth the money is another challenge... So far severeal people are unimpressed with the solectria systems both the AC-24 and AC-55, over priced, overly heavy, and underpowered is what ive been hearing...


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## booksix (Aug 26, 2008)

I've been thinking about the transfer case idea for a while. I'm running two inline 9" GE's and was personally thinking about coupling them to a standard 231 case (2:1 low, 1:1 high) and then on to my 3.15:1 rear resulting in roughly 6:1 and 3:1 gear ratios. To make it fit better, I was thinking about removing the chain drive to the front shaft, cutting the housing in half and closing it back up for a small 2 spd box that would fit under the trans hump of my bmw. I'd also want it to be electronically actuated from inside the car, most likely steering wheel buttons...

Anyway, could be an option. I have yet to see if they can be shifted from low to high while cruising and if the case can be cut in half while retaining high/low etc...


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## Racetrack (Oct 27, 2008)

Bowser330 said:


> http://www.tropicaev.org/#sticker
> 
> Here is the info for price and components...
> 
> ...


Thanks for the link to the Tropica info. The sticker price seems amazing. If the weight given includes the batteries, that is amazing too. Their 60 - 80 mile range claim apparently was not expenienced by the owner whose blog we were linked to--he experienced 20 mile range? 

Anyway, the aluminum frame and plastic body sounds great! If one had a chance to acquire one of these it would be tempting even if the plan was to completely re-power it.

Yes, the AC systems are extremely pricey at the moment. Hopefully when some of these systems reach a mass production point, the price will go down. I would personally like to repower something like a 2000 Regal GS--cheaper than a BMW--and end up with an everyday driver.

Re: Eestor, you are right, and I am not turning blue either, but wouldn't it be nice?

Cheers,

Racetrack


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## Bowser330 (Jun 15, 2008)

it sure would be nice...range that can truly compare with the current ICE setups...and ethen imagine if you have a little propane genset onboard for emergency...


Ebay Item number: 270321834010

electronic shift transmission from Ford truck...should work...although that does open yourself up for potential failures, a nicely styled, manual shifter wouldnt be a bad idea...

how are you liking your inline 9's? what controller(s) are you using? how many amps are you using while cruising on highway? Whats your overall setup?

I say dont cut anything out, just let the other end "freewheel" or if you wanted to get complicated you could attach another alternator or generator to act as a regen system...maybe...


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## Racetrack (Oct 27, 2008)

Bowser330 said:


> it sure would be nice...range that can truly compare with the current ICE setups...and ethen imagine if you have a little propane genset onboard for emergency...
> 
> 
> Ebay Item number: 270321834010
> ...


 
Sorry Bowser330, I don't have a project under way at the moment, although I do have a Valkyrie with one of those gas guzzling v8's in my garage awaiting a complete re-build. My knowledge of ev's comes from research and the fact that I am an Electronic Systems Technologist, so you could slay that I have a foot in both camps.

Re: your suggestion on letting the end with no drive freewheel, this could become a safety issue during braking if you are using rear wheel drive. The ideal is to blend your hydraulic brakes to work progressively with your regenerative breaking. This should be very do-able if you are driving the front wheels. If you are only driving the rears, and doing significant breaking--renenerative--on the rears, you could find your rear end coming around on you--severe overstear. Even with moderate rear wheel only regenerative braking on the rear with no braking on the front, the rear end could break loose in slippery conditions.

Re: using add-on alternator or generator to the un driven end for regen, I don't think this would be worth it, as even a 200 amp alternator can only soak up a little over three horse power. To get an idea of how much braking this would give you, try to imagine how long it would take a 3hp motor to accelerate you car. The other thing is, you would have to go through mechanically connecting your alternator or generator to the undriven wheels--more weight, more complications. If you were going to go to this trouble, I would be inclined just to put the same power train on both ends. You could actually use smaller motors at each end.

Good luck!

Racetrack


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## Bowser330 (Jun 15, 2008)

good point..ok so no regen...

here is a questions...let me try to describe what Im talking about...

so say you want more power to the rear, more than one motor can offer...

so you get two motors, and 2 rear ends...yes...two rear diffs...

you set them up so the main shaft is connected to the motor and the half shafts goto the wheels, have the diffs side by side...the other half shaft, instead of capping it off, is actually connected to the other half shaft....

could this connect of the diffs help make the acceleration more even? because the motors are now connected where as if you used caps they wouldnt be?

your thoughts?


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## Racetrack (Oct 27, 2008)

Bowser330 said:


> good point..ok so no regen...
> 
> here is a questions...let me try to describe what Im talking about...
> 
> ...


Wow! You are really thinking outside of the box! If I understand you, you would like to put two rear diffs side by side and connect the inbord axel drives together. This would actually work, but there are a few serious problems with this:

1. You are adding a lot of weight with the added diff. Why not just use one larger motor?
2. With your suggested setup, each motor would be bucking the other. If one has even slightly less torque, it will end up slowing down to an rpm where its torque does match the other motor, and your differential spider gears will be running continuously to compensate. Ug!
3. This would also shorten the half shafts going to your rear wheels a lot. This will result in more extreme angles in your U joints as the suspension move up and down.
4. You are adding a lot of complexity to your car without any proportionate benefits. Remember, sometimes less is best, and simple is beautiful.

If you want to add another motor, I think the ideal approach is to add your second motor and differential to the front and drive the front wheels with it. With all the front wheel drive cars around these days, the parts would be easy to find.

Here are some of the advantages:

1. Easy balancing of regenerative breaking for all 4 wheels. 
(I noticed in your earlier correspondence that your were really quick to dispense with regenerative braking. I strongly believe this is a mistake. Regenerative braking adds a lot of range in stop and go driving and is one of the atributes of electric cars which help make them GREEN. It could even allow you to reduce the size of your battery pack slightly, and this translates into better acceleration and range, etc.)
2. Doubles your acceleratiion without introducing more wheel spin.
3. Gives you a much better handling and accelerating car, expecially in slippery weather, as you are spreading the available torque of your two motors over four wheels giving you the best of both worlds--the added power you wanted without increasing torque to the rear wheels. This results in more even tire wear front to back.
4. Improves the weight distribution (front to rear) of you car as you are adding the weight of the extra diff to the other end of the car.

Good luck,

Racetrack


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## Jimdear2 (Oct 12, 2008)

booksix said:


> I've been thinking about the transfer case idea for a while. I'm running two inline 9" GE's and was personally thinking about coupling them to a standard 231 case (2:1 low, 1:1 high) and then on to my 3.15:1 rear resulting in roughly 6:1 and 3:1 gear ratios. To make it fit better, I was thinking about removing the chain drive to the front shaft, cutting the housing in half and closing it back up for a small 2 spd box that would fit under the trans hump of my bmw. I'd also want it to be electronically actuated from inside the car, most likely steering wheel buttons...
> 
> Anyway, could be an option. I have yet to see if they can be shifted from low to high while cruising and if the case can be cut in half while retaining high/low etc...


 
Booksix and others,
I'll bring this up again, 

The transmission of choice for the RWD drivetrain you describe is a modified powerglide. it has a 1.8 to 1 low gear and a 1 to 1 high gear and a reverse in a very light and Very Very Very strong transmission. You can build a glide to hold up to a 1000 foot lbs, of torque. Other low gear ratios up to 2.2 to 1 are available. 

With a 3.2 to 1 rear axle, just about exactly what you want.

For a manually shifted unit, what you would want is a short tailshaft powerglide with the bell housing removed (you can buy this kind of case and all of the internal parts new) you would use the available direct pump drive (this unit eliminates the torque converter), used by circle track racers. Further modifications would be a manual shift valve body and an auxillary pressure pump that would run and maintain pressure in the trans only when the traction motor was not running. This auxillary pump would prevent lag on take off from a stop. With an aluminium valve body we are talking about a transmission about 14 inches long that weighs around 45 lbs.

For a fully automatic you would retain the long tailshaft and governor. You would still use the direct pump drive and the auxillary boost pump. Some minor re-calibrating of shift points to match the electric motor requirements and a ported vacuum source hooked to the throttle for the modulator.

Everything I describe above is available OFF THE SHELF right now. Just see a racing powerglide builder. I guanentee you will find at least one builder in every major city. Plus speciallity builders are all over the net.

Jim


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## DavidDymaxion (Dec 1, 2008)

I love the out of the box thinking! Something like this would look really neat on a show car, like a hot rod. It's probably more weight and trouble than it is worth for performance driving, though. What the NEDRA guys are doing is to just direct drive a single diff, sometimes with 2 motors. You could also copy what "Gone Postal" did with 2 rubber drive belts (that wasn't very reliable at their power levels).

Now a response to a comment by Racetrack "[FWD] Doubles your acceleration without introducing more wheel spin."

That is absolutely true in slippery conditions. Since we are in the "Performance" Forum, I'll add a refinement. A RWD sportscar transfers weight to the rear wheels as it accelerates (the extreme case being a drag car that does a little wheely), so it accelerates faster than you might think.

It also takes an inordinate amount of power to exploit AWD at road racing speeds. For example, a 300 hp AWD will destroy a 300 hp RWD in 1st gear. It'll be about even in 2nd gear. In 3rd gear the RWD is faster do to lighter weight and less drag. It takes about 450 hp for the AWD to dominate in 2nd gear, and about 700 hp for it to dominate in 3rd gear, and about 1000 hp for it dominate in 4th. Now something really intriguing would be a 1000 hp AWD A123 car... It could actually be done... Anybody want to give me $200k for the batteries and 4 motors and 4 controllers?



Bowser330 said:


> ...
> so say you want more power to the rear, more than one motor can offer...
> 
> so you get two motors, and 2 rear ends...yes...two rear diffs...
> ...


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## Racetrack (Oct 27, 2008)

This is getting really interesting!

First to Jimdear2, I agree that the two speed powerglide with the mods you listed is definitely the way to go. Three and four speeds are wasted on an electric, and the low weight is fantastic.

To DavidDymaxion, your comments re: weight transfer and the diminishing returns for AWD at higher speeds are all right on. I believe that the AWD option for electrics makes a lot sense if you like to use that extra power around town for pulling away from stops signs, etc, especially in the wet. That and the ease of getting balanced regenerative braking at all speeds are very persuasive arguments for AWD.

What do you think of modulating the proportion of power to front and back motors according to acceleration? i.e. hard acceleration from a standing start generates weight transfer to the rear which would innitiate reduce torque demand to the front motor. On regenerative braking, torque to the rear wheels would be reduced in proportion to the amount of weight transfer to the front wheels. This would be very easy to do!

Cheers,

Racetrack


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## DavidDymaxion (Dec 1, 2008)

That's a great idea. The same accelerometer could bias the front to rear balance for both acceleration and braking.


Racetrack said:


> ... What do you think of modulating the proportion of power to front and back motors according to acceleration? i.e. hard acceleration from a standing start generates weight transfer to the rear which would innitiate reduce torque demand to the front motor. On regenerative braking, torque to the rear wheels would be reduced in proportion to the amount of weight transfer to the front wheels. This would be very easy to do!


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## Bowser330 (Jun 15, 2008)

as far as regen braking goes, what motors are you guys thinking about?

I think we need some people to re-work these forklift motors and actually purpose build them to be EV motors...and im not talking about paint and brushes like Warp motors...

Im talking convert them to perm magnet motors or something...like Electric Louie does...


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## Racetrack (Oct 27, 2008)

Hello Bowser330,

AC induction motors are by far the simplest and most rugged motors built. They have no brushes and many turn incredible revs--13,000!

The AC150 from AC Propulsion is set up for regen. The specs say it will generate about half as much braking torque as acceration torque. I know this is pricey, but it comes with the controler, and integrated high power charger, which can even be used as an emergency power source for your home if the lights go out. BMW has just made a deal with AC for 500 of these units to power a demonstration fleet of 500 Mini's which will go in California and (I believe) Washington DC.

There are other industrial motors and controlers out there--Seimens used to produce these, but the supply seems to have dried up.

UQM builds high quality permanent magnet motors with regen torque equal to accel torque, but these are very expensive, are heavier than a comperable horsepower ac induction motor and don't turn as fast. 

I know of no one who is converting DC motors to permanent magnet and if there was, a completely different controler would be required, because power to the coils on a PM motor have to be timed according to the armature position, although I suppose the original comutator and brushes could do that.

Cheers,
Racetrack


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## booksix (Aug 26, 2008)

I like the idea of the powerglide, but it sounds much more expensive than a modified transfer case. Any reason a transfer case, bolted up just like you'd add an overdrive/underdrive unit, wouldn't work? How much would a full manual shifting powerglide run?


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## Bowser330 (Jun 15, 2008)

Racetrack said:


> Hello Bowser330,
> 
> ....I know of no one who is converting DC motors to permanent magnet and if there was, a completely different controler would be required, because power to the coils on a PM motor have to be timed according to the armature position, although I suppose the original comutator and brushes could do that.
> 
> ...


Someone out there has got to be doing this....somewhere....


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## Jimdear2 (Oct 12, 2008)

booksix said:


> I like the idea of the powerglide, but it sounds much more expensive than a modified transfer case. Any reason a transfer case, bolted up just like you'd add an overdrive/underdrive unit, wouldn't work? How much would a full manual shifting powerglide run?


Booksix,

A manual shift powerglide can be quite inexpensive, I built the one I used in my ultralight twin engine pulling tractor for about $500.00. But that was because I wanted a valve body (about $300.00) that had the ability to lock low and reverse together so I could wind up the High Stall converter before I started the pull.

If you shop around the older dismantler yards you might find a good glide for 50.00 like I did. I just cleaned it up, put my valve body on it and ran it. It worked great until it "somehow" got filled up with water. I have to rebuild it now. opps Sorry off topic.

You can buy a completly rebuilt racing level manual shift powerglide from TCI for (last I looked about a year ago) about $1000.00 dropped at your door.

If you are willing/able you can install a manual shift kit into a stock glide valve body for around a $100.00.

Depending on your scrounging abilities, mechanical skill level and what you want, you could make your own pump drive/coupler/adapter plate/trans mount/driveshaft set up and put a used stock glide in for near nothing, after all this is a DIY site.

The auxillary pump to keep pressure up while stopped is a simple set up. There are kits available to keep fluid flow up in auto transmissions for towing purposes that might do the trick. See a good trans man for info on hookups

There are people who did without any of this and put up with a slight lag on take off while pressure built up.

A 45 pound shorty glide with all the goodies, built by a professional from all new parts might go as high as $3500.00, maybe even more when you figure in all of the extras like pump drive/coupler/adapter plate/trans mount/driveshaft set up professionaly built.

A last note to the nay sayers. Automatic transmissions WITHOUT a torque converter are at least as efficient as a manual transmission. Almost ALL of the power loss occured in the torque converter.

Have fun,
Jim


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## piotrsko (Dec 9, 2007)

Jason Lattimer said:


> You are over thinking this too much. If you are using a rwd vehicle like I intend to use, you can get drag racing diff. with different ratios. My Ford diff. 7.5 , 8.00 , and 9" rear ends can be bought with or without posi and you can get ratios that go all the way up to 6.00 to 1 in some racing applications. Just thought this info might be of some help. Also, if you have a front driver, a lot of them already have high ratios, my exs Taurus has a ratio of 4.10 to 1 in the front axle.



what he said except for: they also make gear sets for FWD to about 5.86/6.32 go look at Richmond gear online.

why not gut a 4wd vehicle and direct drive front and rear diffs'? Most Dana's can also go to 6.00. Worst case you will solid mount motors, and run the existing drive shafts with couplings. Warp even has u-joint adapters premade to their motor.


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## luch (Apr 21, 2009)

Really weird but the 91 Chevy (GEO) tracker 4x4 I just bought as a donor car has the 5.1 ratio in low 4WD (transfer case in LOW with manual locking hubs). Normal HIGH is 4.51 rear end. Its an automatic but I'm willing to experiment. The automatic is a 3 speed so I'm hoping for a miracle. I'm gonna bolt a Japanese NYK 8.5 inch separate field forklift motor and a old and moldy GE EV-1 SCR controller at 84-96 VDC and see what happens.

A guy selling on eBay converted a 4 speed Tracker 2x2 at 144 VDC with a Curtis and had a blast (He is Asking $12K). He wants to sell to build another one.

I'm going for a GE EV-1 at 84-96 VDC ($2.4K target expense) and see what happens, Yah gotta take a chance in life. The worst that could happen is, I could learn a lot and have some fun. What more could you ask for when your almost 60.


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## sunworksco (Sep 8, 2008)

Bowser330 said:


> I want to mimic the tango design and do direct drive with two curtis 500amp controllers and two FB1 9"s....yes i do realize thats 6000$ right there...yikes...
> 
> point is i need to reduce the gearing between the motor and the wheel by about 4:1-5:1.....and I could use some help to figure out ways to do this....
> 
> ...


 Use a Honda limited-slip differential with Kevlar belt drive with pulley system.Or use a Speedway Engineering differential.


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## crustycar (Aug 31, 2009)

planetary if I am understanding you do not desire a transmission


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## crustycar (Aug 31, 2009)

and you could easily differentiate electronically


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