# Planning a Sunbeam Alpine conversion.



## rfengineers (Jun 2, 2008)

I have a 1962 Sunbeam Alpine sitting on my carport waiting to be restored. I am considering an EV conversion. This will be my first conversion, so please excuse me if I say something obvious as if it were a revelation. 

Here is what I am thinking; Tell me if I am crazy:

Motor:
I want to mount a TransWarP9 in the space formerly occupied by the transmission. It will fit, but I may need to provide forced air cooling to the motor. 

Drive System:
The turbo400 should couple easily to the propeller shaft with close to the same angle as the original equipment. The differential is a 3.89:1. The manual specifies 17.3mph per 1000rpm.

Batteries:
The batteries can be distributed to three areas. Under the bonnet, behind the seats, and under the boot (where the fuel tank used to be). I should be able to carry 600-700lbs of batteries without over-stressing the suspension or brakes.

Goal:
I hope to end up with a 2-seat convertible with 40-miles of range and a top speed of around 60mph. Primary use will be around town and on country roads. No freeway use is intended. Rapid acceleration is not a requirement. I am trying to compromise between simple and inexpensive so I think I am tied to lead-acid technology for the moment. 

Questions:
Is the direct drive system a reasonable idea?
The TransWarP9 direct drive makes things simple. Can I operate at 72V to keep things inexpensive or will low Voltage give me low-speed torque problems?
If 72V is too low then what voltage should I use?
What am I overlooking?


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## joseph3354 (Apr 2, 2008)

that is a sweet little car for an EV conversion.with the low starting weight of the vehicle it should be a fine candidate for a direct drive system.eliminating the transmission should save quite a bit of weight to use towards batteries.i would shoot for at least 120v.check out the beetles at evalbum.com they are close to that weight.


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## xrotaryguy (Jul 26, 2007)

Having owned lots of 20 and 30 year old Japanese cars, and having owned a couple of 30 year old British cars, I would like to respectfully point out that your Sunbeam has a pretty decent resale value  One of the reasons that we want electric cars is that they're reliable. British cars aren't reliable. They're light, cute, fun (when they're actually running)... and that's about it. If you really want a small old car with no roof, you might look into a Datsun roadster. The British auto industry didn't go out of business because they didn't feel like selling cars anymore. They went out of business because the Japanese showed the world how nice a reliable car could be.


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## joseph3354 (Apr 2, 2008)

xrotaryguy said:


> Having owned lots of 20 and 30 year old Japanese cars, and having owned a couple of 30 year old British cars, I would like to respectfully point out that your Sunbeam has a pretty decent resale value  One of the reasons that we want electric cars is that they're reliable. British cars aren't reliable. They're light, cute, fun (when they're actually running)... and that's about it. If you really want a small old car with no roof, you might look into a Datsun roadster. The British auto industry didn't go out of business because they didn't feel like selling cars anymore. They went out of business because the Japanese showed the world how nice a reliable car could be.


reliability should not be an issue,the ICE and transmission being removed and replaced with an electric drive system would increase reliability.british wiring has a bad reputation,but rewiring a small car of that type is not a huge undertaking.also increasing reliability.


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## onesojourner (May 6, 2008)

joseph3354 said:


> reliability should not be an issue,the ICE and transmission being removed and replaced with an electric drive system would increase reliability.british wiring has a bad reputation,but rewiring a small car of that type is not a huge undertaking.also increasing reliability.


X2 all the junk that breaks is taken out. One of the main problems with british cars is wiring and leaky oil both of witch should not be an issue.


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## Mastiff (Jan 11, 2008)

As long as the suspension, steering assembly and the differential are in good condition it should be fine.

My only problem with your conversion is that you're placing a Warp9 on a car that originally had less than 100HP in it's engine.

This means the Warp 9 at high power could easily destroy your differential.

I would be very careful about accelerating in that car especially because you'll be adding a lot of weight with the lead batteries meaning more stress on the differential.

I myself would limit the maximum amperage on the motor controller to a conservative amount, otherwise you could ruin the vehicle.


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## joseph3354 (Apr 2, 2008)

what mastiff said.you can reduce costs also by using a smaller motor which could also be used with a less expensive controller.you could still hit the 120v mark as well.


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## rfengineers (Jun 2, 2008)

Thanks to everyone for the advice. You raised some questions that I hadn't considered.

As far as the Sunbeam having more value as an original, well... I want the car for me, not for someone else. I have delayed beginning this restoration for several years because I just did not want to put that damn British tractor motor back in the car. I really like the EV idea. The reliability issue has been well answered by others, but let me add this:

_"Why are British auto mechanics so mean? 
Because they drink warm beer. "

"Why do British auto mechanics drink warm beer? 
Because they have Lucas refrigerators! "_

Another point in favor of the Sunbeam, it sits on a true chassis which can be easily beefed up if needed. (see Sunbeam Tiger)

If I destroy the rear end I have quite a few options for replacing it. (Again, see Sunbeam Tiger)

I think the way I am going to proceed is this:
Install the TransWarP9.
Build boxes that can hold enough batteries to go to at least 120V.
Install 6 12-volt batteries and use a 72-volt controller that I borrowed from a friend.

After I test drive the car in this configuration I will have a better idea what I need to do to get to my target range & speed.


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## Manntis (May 22, 2008)

rfengineers said:


> _"Why are British auto mechanics so mean?
> Because they drink warm beer. "
> 
> "Why do British auto mechanics drink warm beer?
> Because they have Lucas refrigerators! "_


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## xrotaryguy (Jul 26, 2007)

onesojourner said:


> X2 all the junk that breaks is taken out. One of the main problems with british cars is wiring and leaky oil both of witch should not be an issue.


You used the word brakes...  What are you going to do about those Giring brakes? Just curious. Also, I'm sure you plan on using the differential. I learned to rebuild a differential while I was a British car owner. The diff only had 88k on it. I have never had to rebuild a differential on any other car let alone at only 88k.

In short, removing the engine and transmission does not eleminate all the British parts. 

I don't really want to discourage you from building this car. As you're well aware, the car is already super light, so it has huge potential as an EV. You sound like you know what you're getting into. I'm sure this will be a fun car.


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## rfengineers (Jun 2, 2008)

xrotaryguy said:


> What are you going to do about those Giring brakes? Just curious. Also, I'm sure you plan on using the differential...


The brakes are a concern. Does anyone have a suggestion?

Except for the steering box, this is the same car that carried a small Ford V8 as the Sunbeam Tiger. I have the shop manual for the Alpine, but not the Tiger, so I don't know what changes were made to the suspension, brakes or differential. Web research has not answered those questions either.

I plan on building this in stages. First is a minimal 72-volt system to evaluate acceleration and top-speed. Then I will make a decision on the next step(s). This is a learning experience!!

While I am mostly thumbs (I'm an electrical engineer) when it comes to this type of stuff, my wife is a pretty good welder and body-work gal. My brother-in-law, who is helping me design and build the conversion, has been designing and building race-cars for 35-years. So I think we have a pretty good team with most of the necessary skills and knowledge.


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## joseph3354 (Apr 2, 2008)

sounds like you are off to a good start.please keep us posted on your progress.this will be a very interesting project!


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## avn-tech (Jun 16, 2008)

RFengineers,

I would recomend you look at selling the Sunbeam and using the money to build a different car. If you like the two seat convertable, try an MGB (they are much more common, although an MGB owner would cry sacrilige). There are very few Sunbeams left (Alpine or Tiger).

While I understand that you are building the car for yourself, life will go on and the car will be here when we are gone. At that point someone will probably want to return it to near original condition.

I have had this talk with friends in the past (Shelby GT-350, Piper Airplane). Both have come back later and said they were sorry and wished they had listened. The Shelby was sold for Apprx 1/2 of what a near stock car would have sold for. The piper is currently fo sale, at 1/2 of what was spent on the restoration and upgrade (he was ging to keep this one forever).

Ultimatly you will decide what is best for you. (I listened to people who said they wished the had kept their car from high school. I kept mine a 1969 Firebird Convertable, all original and needing a complete rebuild for the last 25 + years)

Good luck
Avn-Tech


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## DVR (Apr 10, 2008)

Mastiff said:


> As long as the suspension, steering assembly and the differential are in good condition it should be fine.
> 
> My only problem with your conversion is that you're placing a Warp9 on a car that originally had less than 100HP in it's engine.
> 
> ...


It all depends on what controller you want to use.

Grassroots couple the warp9 to different controllers for different output.
eg:
*Similar in power to a four cylinder gas vehicle*​ *War P 9" Motor $ 1,670.00*
*Logi144AFX 750amp Controller $1,345.00 *



*Similar in power to a small block eight cylinder gas vehicle.*​ *War P 9" Motor $ 1,670.00*
*Z1K-HV Controller $ 2,550.00*


So unless your planning on running a Zilla at 144V I think you’ll be OK.


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## Bottomfeeder (Jun 13, 2008)

I am about to buy the motor and controller for a Triumph Spitfire conversion. At first I had planned on using the transmission, but after multiple Spitfire forum members suggested I go with direct drive, I started looking into it. The more moving parts I can remove the better!

I haven't done to much with differentials and gearing, etc. So, I'm curious how to calculate what the top speed of the Spitfire would be. I suppose I'll need to know the top RPM of the TransWarP 9" as well. The spec graphs go up to 5,000 RPM. Is that the safety limit for these things?

Sorry for jumping on this thread, but I'll be facing the same issues with the Spitfire. (Including the angry purists!)

-D


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## gerd1022 (Jun 9, 2008)

very interesting... i am starting a triumph spitfire conversion as well... why would you go with a direct drive for a vehicle like this?

also: @5000 Motor RPM (limited by your controller to avoid blowing your motor), with the diff being a 3.89:1, thats 1285 RPM at the tire, and with a tire circumference of about 70 inches (i think thats about what a 175/75 r13 tire is) so thats about 90000 inches per minute, or about 85 mph. I think...


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## Bottomfeeder (Jun 13, 2008)

My main reason for removing the transmission is to get rid of as much moving parts as possible. My transmission is 44 years old, and a high torque motor may just kill it. All of the spinning weight and dead weight of the tranny will only slow it down. I suppose I'm curious as to a good reason to keep the transmission. Will my performance suffer with only one gear? There is a lot about motors I don't know.

If this is being debated elsewhere, please feel free to just send me a link so I can read the pros and cons.

Thanks!


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## gerd1022 (Jun 9, 2008)

i have two reasons for wanting to keep it:

1. reverse: Instead of dealing with electronic reverse, you can just shift it into reverse no problem

2. efficiency: Ive been doing some simulations on the EV calculator (just google it), and with no transmission, it would be like running in 4th gear all the time. According to the calculator with my specs for motor and controller and all that, i go from about a 55 mile range at 40mph in 2nd gear to a 41 mile range at 40mph in 4th gear. This numbers might be a bit high, but from what ive seen, you almost always have less range using higher gears.

also: with a transmission i believe you can get away with a smaller motor and thus less cost.


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## EliteEV (May 6, 2008)

Hang in there, rfengineers! I'm in the process of converting a 1974 Lotus Elite, and am happy that it will take a few weeks to get my Warp9 and adapter because there's so much work to do to the car. And yes, that includes designing and installing a new wiring system...the existing one has been "repaired" by too many hacks. Good luck.


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## gerd1022 (Jun 9, 2008)

hmm interesting... i am playing around with the calculator a bit more, and i've found that the Warp 9 doesnt have the same large decrease of range with different gears. In fact, it is only the 9" ADC (FB4001) that has that problem...

I wonder if it has something to do with the motor itself or perhaps a typo in the motor specs.


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## Bottomfeeder (Jun 13, 2008)

The TransWarP 9" is intended to replace the transmission and motor. I had decided to use the transmission and I was just about to buy the motor, but now I'm not so sure...

Sorry again, RFengineers. I almost bought a Sunbeam for a few hundred dollars for my EV project. It looks like it will be a fun car to drive around. I think your idea to start with 72V, with plans for more batteries in the future, is great. There's no reason to overbuild the car. If it works fine for you with 72V, you'll save plenty of money that way. Keep us updated with your plans!

-D


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## gerd1022 (Jun 9, 2008)

oh... the transwarp has another transmission built in... ok that could be fine then. youd still have to worry about reverse tho...

i should stop trying to give advice when i dont understand the problem... sorry.


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## Bottomfeeder (Jun 13, 2008)

I don't think my last post was clear. The TransWarP 9" motor has a yoke so it can couple to the driveshaft, but has no internal transmission. But the motor is designed to replace the tranny. At least that's what I understand from http://www.go-ev.com/motors-warp.html.

I was thinking about using the transmission and getting a more standard motor, but now I'm not so sure.

I think the pain of electric reverse would be outweighed by the possible weight savings of the transmissionless EV. Just my 2 cents.

-D


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## rfengineers (Jun 2, 2008)

Wow, what a can of worms!

Now I have people telling me that the new "Get Smart" movie is going to increase the value of my Alpine since Max drives a Sunbeam Tiger.

I am moving slowly, since I have to work for a living. The ICE and transmission have been removed and I am currently working on the brakes and fixing body rot under the doors. 

I suppose that when I get to the point of doing irreversible modifications I will make the final decision about selling the rolling chassis and going with another car for my conversion.

I will start taking some 'before' pictures as soon as I get back from vacation next week.


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## rfengineers (Jun 2, 2008)

After a lot of thought, I have decided to wait on the Sunbeam conversion. The car is not easily replaced and I don't want to use it as my "learning experience". 

So, I have a new donor car for my first conversion! I picked it up earlier this week. It's a 1996 Pontiac Sunfire. Today the motor/tranny got pressure-washed. The motor will be coming out this weekend. Pictures to follow.


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## rfengineers (Jun 2, 2008)

Well, the learning experience is about done and it is time to get started on the Alpine!

We brought the car to the shop this weekend.


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## dtbaker (Jan 5, 2008)

sounds FUN. i would vote for a modest 96 volt system with 8v batteries as a balance between range and volts and a ADC 8"... unless you want to build an electric Tiger. You'll have room for lots of batteries with space behind seats and trunk.

I had a '66 Tiger, so know for a fact that if you replace driveline with Mustang, you should handle all the HP you want. Be careful with the front xmember as they tend to rust through in hidden places; you might want to weld a plate on the bottom and add some bracing to the engine bay.

electronics are SIMPLE in an Alpine, and the least reliable part (fuel pump) you are ditching.

You will probably want to go for mustang brakes... the Alpines are a little heavy with all the steel in the body, and the original brakes are pretty marginal.


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## rfengineers (Jun 2, 2008)

We finally got some time to work on the Alpine. Started to grind on the rocker panels and found that they were solid bondo!

To make a long story short: There is a bunch of new metal from wheelwell to wheelwell on both sides! Also, patches on the floor and around the 12V battery box.

This is going to be a long project!


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## Jeff Howarth (Sep 8, 2009)

Hi RF Enginerrs,

I am interested in your project as its not common in the UK and I am a long time sunbeam owner.
I am interested to see how you progress - good luck!
Its probalby a little more eco freindly than my Tiger.

I saw you asked about brakes, the standard tiger uses the same brakes as the alpine but they both had a booster driven by the engine vacuum
An alternative is a smaller master cylinder and no booster.

regards

Jeff




rfengineers said:


> We finally got some time to work on the Alpine. Started to grind on the rocker panels and found that they were solid bondo!
> 
> To make a long story short: There is a bunch of new metal from wheelwell to wheelwell on both sides! Also, patches on the floor and around the 12V battery box.
> 
> This is going to be a long project!


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## rfengineers (Jun 2, 2008)

Jeff Howarth said:


> Hi RF Enginerrs,
> 
> I am interested in your project as its not common in the UK and I am a long time sunbeam owner.
> I am interested to see how you progress - good luck!
> ...


Hi Jeff,

Thanks for your interest. 
Unfortunately, the project is on hold due to lack of funds. I will post more information after the upcoming financial recovery!
Joe


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## RootesRooter (Sep 10, 2009)

When you get back into your project, you might want to contact Cloud Electric in Kent, Washington. They do car & boat electric conversions, and did a Series I about 4-5 years ago for a professor down in SanFran. I had a chance to look it over and talk to the Cloud engineers.

I don't remember which motor they used, but the owner kept the 4-speed tranny. The Cloud guys wouldn't say so directly, but I got the impression they thought that was a waste, given the extra weight and friction loss.

Early Series (particularly I & II) cars are the way to go if you're using a Sunbeam Alpine. In restorable condition, they're still relatively plentiful and cheap. At any one time, there are several available on eBay or Craigslist. Body rigidity is very strong; there are no real differences there between an Alpine and a Tiger. That was considered their Achilles Heel back in the day, as the extra x-bracing underneath (added to prevent cowl shake) raised the weight to about 2200 lbs and left the 4-banger Alpine less competitive on the track. For your purposes, it's perfect.

The Tiger, at 2600+ lbs, did use stronger front springs, probably recommended in your case.

I believe the Cloud Alpine used a dozen heavy-duty batteries (4 up front, 4 behind the seat, 4 in the trunk), probably weighing around 1000 lbs. Losing the piston engine would mean a net gain of 800 lbs, or around 3000 lbs total. The Girling disc/drum brakes are fine for street purposes, but you may want to add an aftermarket booster.

Someone mentioned differentials. The Alpine unit is generally strong enough, BUT, the bolts holding the ring gear have a HIGH tendency to loosen and eventually break off over time, sometimes blowing up the unit. Replacing the odd-size bolts requires a bit of sleuthing (try the Sunbeam Alpine Owners Club of America board) but with new bolts, you shouldn't have any worries in this department.


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## dtbaker (Jan 5, 2008)

The cross-member in the front has a typical place for rust right in the middle. Guys in my Tiger club often had to weld a plate underneath to stiffen them back up. I can't remember what the rear diff was, but I think it was a mustang rear end in the Tigers.... just a big 'ol live rear axle that jumped all over when you hammered it.


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## rfengineers (Jun 2, 2008)

dtbaker said:


> The cross-member in the front has a typical place for rust right in the middle. Guys in my Tiger club often had to weld a plate underneath to stiffen them back up. I can't remember what the rear diff was, but I think it was a mustang rear end in the Tigers.... just a big 'ol live rear axle that jumped all over when you hammered it.


The front cross-member looks good, but I will check it again. I did have to weld in a couple of new steel beams behind the rocker covers. They were mostly rusted away.


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## dtbaker (Jan 5, 2008)

rfengineers said:


> The front cross-member looks good, but I will check it again.



might not have been stressed too much w/ an Alpine. The Tiger's engine was WAY heavier, plus the extra torque.... I ripped two motor mounts apart after 'tuning' the motor.


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## RootesRooter (Sep 10, 2009)

rfengineers said:


> The front cross-member looks good, but I will check it again. I did have to weld in a couple of new steel beams behind the rocker covers. They were mostly rusted away.


If you still have much more body rust to deal with, you might want to keep an eye out for another, less-rusty body. They're out there, especially Series II's. 

BTW, in the Cloud Alpine, the trunk floor and spare tire box were all pretty much cut out to make room for a custom battery tray, and the deck in back of the seats was also cut out and lowered.

I've yet to come across an Alpine front crossmember suffering from structural failure, and very few from significant rust. The X-frame and the front mount areas for the rear leaf springs are more likely candidates for rot underneath.

To the other poster, the Tiger rear end is a Salisbury unit.


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## dtbaker (Jan 5, 2008)

how did this alpine turn out? ever finished?

I just bought a '62 series 2 Alpine off ebay, and while it is a good runner with original engine, I bought with intent to convert..... very curious about what electric motor will fit into an alpine without breaking the drivetrain, or whether I should change to a mustang or some other drivetrain to handle torque.


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## RootesRooter (Sep 10, 2009)

Both electric Alpines I've come across in the Seattle area retained the original tranny and diff. The tranny is plenty strong. The diff probably is for all but the most 'enthusiastic' drivers. As I wrote in an earlier post in this thread, EVERY Alpine owner should replace the diff's ring gear bolts, which invariably loosen due to their soft washers, break and fall into the soup - and that's if you're lucky.




dtbaker said:


> how did this alpine turn out? ever finished?
> 
> I just bought a '62 series 2 Alpine off ebay, and while it is a good runner with original engine, I bought with intent to convert..... very curious about what electric motor will fit into an alpine without breaking the drivetrain, or whether I should change to a mustang or some other drivetrain to handle torque.


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## Guest (Mar 21, 2011)

dtbaker said:


> how did this alpine turn out? ever finished?
> 
> I just bought a '62 series 2 Alpine off ebay, and while it is a good runner with original engine, I bought with intent to convert..... very curious about what electric motor will fit into an alpine without breaking the drivetrain, or whether I should change to a mustang or some other drivetrain to handle torque.


I would not use anything less than a 9" motor. As for breaking the drive train, I think it is more a factor of how heavy a foot you have and how much your controller can pump to it when you slam the throttle. If you have a soliton you can adjust the ramp up to keep your drive train intact. 

Pete


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## dtbaker (Jan 5, 2008)

RootesRooter said:


> Both electric Alpines I've come across in the Seattle area retained the original tranny and diff. The tranny is plenty strong. The diff probably is for all but the most 'enthusiastic' drivers. As I wrote in an earlier post in this thread, EVERY Alpine owner should replace the diff's ring gear bolts, which invariably loosen due to their soft washers, break and fall into the soup - and that's if you're lucky.


very good info, I will add a differential check/rebuild to the list of conversion tasks for this one.... I have more homework to do on a couple aspects, and sure wish I could talk with any other Alpine conversion people.

Current plan would be 9"ADC motor, probably curtis 1231 controller (Zilla and Soliton are just too pricey and I really hesitate pushing more than 500amps thru anyway, so why pay for 1000 amp max), 144v worth of either 100ah, or 160ah LiFePO4.

I am wondering:

- if CanEV, or any of the other clutched design adaptor people have the Alpine adaptor in their past, or if I should consider changing to a more modern transmission like the M5 from the 2.8L v-6 Ford motors. This one in particular is popular for v-6 conversions because the motor fits in the Alpine bay, but I am wondering if there is a good tranny the would NOT require modification to the tunnel.

- if I should stick with the wire-wheel knockoff hubs, or the regular steel wheels... I have both with the car I think... although I am unsure of the condition of the wire wheels yet.


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## Guest (Mar 22, 2011)

Check out Synkromotive controllers. I guarantee you will want to belt out more than 500 amps. Curtis controllers are a main stay but are anemic. You need amps unless you plan on 156 volts or higher. Then volts become your friend. Your motor of choice can handle more amps than 400. Check out the continuous amp output too. The higher the better. If its like 250 you could be in trouble fast. Many vehicles run at freeway speeds in that range of amp draw which would push any controller to the limits. My controller is like 450 continuous. Well above my cruising range. More volts help too. More volts and more amps. Don't skimp on the controller because in the end you will buy the curtis and you will buy the Soliton1. That will cost more in the end. So buy the best first and just run your car at a lower voltage if you must. I'd go for as high of voltage as you can and the best controller you can and lithium batteries and such because in the end you will be there anyway and if you start small and grow it will cost way more. It may cost a bundle up front but I know you will want to upgrade and that means more batteries a different controller and a different charger. The cost of upgrading is expensive. Your needs dictate you don't need much but after you get a good taste of electric drive your wants will overpower your needs. Ask me how I know that one? It will take longer but you will have a better vehicle in the end. 

Pete


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## dtbaker (Jan 5, 2008)

gottdi said:


> Check out Synkromotive controllers. I guarantee you will want to belt out more than 500 amps.



I really DONT want to be able to send more than 500 amps since I will most likely build with 144v of 100ah cells. I don't really want the ability to pull more than 5C because I don't want the temptation to suck the life out of the cells.

I am not intending to build a dragster, just a 'decent performer' minimizing cost and maximizing system life. 500amps at 144v to a ADC 9" in a 2000# car will be more than enough for a 50 year old vehicle.


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## Guest (Mar 23, 2011)

My MG is not a dragster either but it can take a good whopping 500 amps for a moment or so to get the car up to speed in a reasonable time frame to keep with traffic. I keep an eye on my battery voltage closely and see frequently close to and more than 500 amps. I am not talking motor amps either. I am talking battery amps. Yes, you will want a controller that can belt out that and keep an eye on battery amps. My synkro will monitor both the motor and battery amp draw and log them. I do not hot rod my MG. It is not a race car, it is a sports car. Somehow folks mix the two up. Yours is a sports car and not a hot rod or race car. For that you'd want a soliton1 or Zilla 2k. I just think that the curtis is an anemic controller. Some folks don't seem to think so but my little 72 volt 550 amp controller I had with my first conversion did a whopping good job. For a 72 volt system and a steel bodied Ghia it push it to 65 mph no problem. Nothing more than that but it would handle high amperage well. Better than any curtis. If you go with the curtis make damn sure you have a whopping good heat sink and large cooling fan connected. I have a picture of my 72 volt controller with the heat sink and fan. I could no longer get it hot with the sink and fan attached. 

I guarantee you will at some time or another wish you had the ability to give it more ooomph. With a synkro you can program any parameter in to limit amps too for both the motor and battery pack. You can limit throttle too. You can have RPM and thermal cut back if motor or cells get to hot. Over all a pretty nice setup. So far so good. Two years with a beta unit and a few months now with a production model. 

Pete


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## dtbaker (Jan 5, 2008)

gottdi said:


> Check out Synkromotive controllers. I guarantee you will want to belt out more than 500 amps.


ok, ok, I am leaning more toward making a really SPORTY Alpine as long as I am doing it... but still afraid of toasting motor or batteries. I'd like some way to reliably monitor motor and cell temps to prevent too heavy a foot for too long.

so, I am attempting to compare the 'higher end' 1000amp controllers to compare and contrast features for safety, durabillity, etc. Soliton, the new Netgain Warp controller, Raptor, Zilla if they ever come back.... all in the running. I will try to find the info on Syncromotive. I would you compare to Soliton for instance?

...and a related topic is whether anyone has done any testing to see just how long you can push a 9" at 1000amps, or TS/CALB cells at 10C before temperature becomes an issue?


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## Guest (Mar 25, 2011)

The Synkro does not does not fall into the same category as the Soliton1 and Warp controller. I am only stating those two because they are the only NEW 1000 + amp controllers available. There should be plenty of folks with Soliton1 controllers to give you the information you need. As for the Warp, I only know of one so far that is currently running one and that is Corbin. The Synkro is an excellent controller and I have had my controller in the 600 amp zone for over a minute with no ill effects. I have never had it over heat. It is fully programmable. I can't compare them myself because I don't have a Warp or Soliton1 but I'd like to have all three to test and compare in a car. I think it would be an excellent show or program to do a comparison of all three in their natural habitat. Maybe I can sometime during the summer. 

Pete


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## Guest (Mar 25, 2011)

Of the two biggies I'd bet my paycheck that the Soliton1 is King all the way around. So far there is no refuting that. 

I'd almost bet that they would kick the butt off the zilla too. In some areas the Soliton1 is in its own universe. It really is good. 

Pete


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## dtbaker (Jan 5, 2008)

The Soliton sure is an attractive package, but double the price is hard to swallow. I do like the stated features. It would probably run cool enough just with air for me since I would only push it at the occasional stoplight, not extended highway. I am facinated that the docs say it doesn't need a main contactor, that simplifies some things and saves a little expense!

I would LOVE to see some tests showing:
- how long a DC 9" motor can handle 1000amps until it approaches a reasonable temp limit from 'ambient'. i.e coming off a stoplight, would I have 10 seconds, 30 seconds, or a minute joyride before I'd have to back off?
- how long a TS-100ah cell can dish out 1000amps (10C) until internal temp is approaching rated limit... this would be meaningful if we had a good idea how the internal temp translated to what we could pick up at one of the terminals with a good temp sensor.


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## Qer (May 7, 2008)

dtbaker said:


> - how long a DC 9" motor can handle 1000amps until it approaches a reasonable temp limit from 'ambient'. i.e coming off a stoplight, would I have 10 seconds, 30 seconds, or a minute joyride before I'd have to back off?


There's no definite answer on that because it depends on RPM, ambient temperature, how well the brushes are seated etc, but I doubt you'll get a minute. Not with ONE WarP 9". 








dtbaker said:


> - how long a TS-100ah cell can dish out 1000amps (10C) until internal temp is approaching rated limit...


Motor current is NOT equal to battery current EXCEPT when the controller is completely off (ie no throttle, no current) or when the controller is 100% on. To put it simple a controller converts power to power, but since motor voltage is proportional to RPM it means that when the motor is still the only power drawn from the pack is to overcome the losses in the controller, cables and motor.

This means:

Pmotor = Pbattery (I'm ignoring the losses here)

Umotor*Imotor=Ubattery*Ibattery

But since the motor voltage is very low at your red light but the pack voltage is what it is (a constant if you ignore the sag) the battery current must be very low even when motor current hit 1kA. So for example if your motor voltage is half the pack voltage and your motor current is 1kA your pack current will be half that, or 500A. If your motor voltage is 1/4 pack voltage, your battery current will be 250A and so on.

So even with a rather "crappy" pack you can still get 1kA out of the controller provided the motor voltage (and thus motor RPM) is low enough compared to the pack voltage.


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## dtbaker (Jan 5, 2008)

Qer said:


> But since the motor voltage is very low at your red light but the pack voltage is what it is (a constant if you ignore the sag) the battery current must be very low even when motor current hit 1kA.


this is the concept that continues to elude me... I can't follow how motor current can be higher than battery current. Is this the magic part of controllers? Basically 'pulsing' high amps chunks of current to motor?

If I AM following... it sort of means that for the first say 10 seconds of acceleration from a stop light it is most likely that if the motor amps were limited to 1000amps, the battery amps would not see 1000amps until the last few seconds.

Has anybody done any 'real life' testing with a 9" motor and cells wired with good thermocouples? starting 'cold' at summertime ambient of something like 80 deg F, and putting the hammer down for 30 seconds at 1000amps and plotting the temp rise?


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## Qer (May 7, 2008)

dtbaker said:


> this is the concept that continues to elude me... I can't follow how motor current can be higher than battery current. Is this the magic part of controllers? Basically 'pulsing' high amps chunks of current to motor?


Pretty much, yes. The controller turns on and off the current very fast and the induction in the motor and the capacitor on the battery side smooths things out so that if you have 100 Volt in and the pulse width is 50% the average voltage over the motor becomes 50 Volt despite that it's 100 Volt you switch.

On the battery side the current draw is, for example, 1kA, 0, 1kA, 0, 1kA and so on, but it gets smoothed out by the capacitor so you get an even (well, more even) current of 500 Amps.



dtbaker said:


> If I AM following... it sort of means that for the first say 10 seconds of acceleration from a stop light it is most likely that if the motor amps were limited to 1000amps, the battery amps would not see 1000amps until the last few seconds.


Exactly!

And if you want to protect your battery you can set maximum battery current to, for example, 500 Ampere and if you have a pack voltage of 100 Volt (as above) it means that as long as the motor voltage isn't higher than 50 Volt you get 1000 Ampere (since 50*1000=100*500) but when motor voltage starts to rise above 50 Volt the controller will start decreasing the motor current to keep the battery current at 500 Amps maximum. So when motor Voltage reach pack voltage (100 Volt) the motor current is down to 500 Ampere.

Of course, then you have to add voltage sag, losses etc, but, well, na. Too complicated. The Soliton recalcs everything 100 times/second anyway so you don't have to worry. 

(and yes, there's other controllers that behave the same, for example Zilla has similar parameters you can set and works in a similar way to protect both motor and pack, of course)


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## dtbaker (Jan 5, 2008)

ok, I am liking the idea of a 'modern' controller more and more for high performance... I could set motor amps to 1000a and battery to 500a, have great accel off the line and be pretty sure I won't pull over 5C from 100a cells even when at full steam for *short periods* of accelleration.


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## clivepocock (Jul 8, 2019)

Hi 

I wondered if you could update us on the progress/status of your Sunbeam Alpine please ? Here we are mid 2020 and I am considering a similar project and would love to get the benefit of your experience please.

Best regards
Clive


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## dtbaker (Jan 5, 2008)

Hi Clive, sure I'll give an update....

I've been messing with my eMiata for the last couple years as a build/test platform before taking on the Alpine because the Miata tranny, suspension, brakes were all good to go. My intention shifted to working all the bugs out on the Miata, and then transplanting EVERYTHING to the Alpine. I now have 25k electric miles on the eMiata, upgraded transmission, brakes, ended up with a Warp9, Zilla 1k, 156v x 130ah CALB super fun little car that I hesitate to take apart.  With this setup, the gear ratios are too low... and what I may do is is swap in the getrag rear diff with a final ratio of 2.73 to give me a more useful 1st gear, and a nice low rpm for highway speed.

Given my experience with the need to beef up the Miata driveline to handle the torque, my opinion is that you should definitely consider a complete remove/replace of Alpine driveline, brakes, and suspension as long as you are doing it. The Alpine is so narrow, this is going to take some creative design, a good welder, and likely a decent local machine shop.

You COULD go with the stock stuff if you would be satisfied with low performance, limit the power, and have the patience to restore original to best condition possible. IF I'm going to all the trouble to convert, I wanted to build an eTiger.

so..... back to the Alpine. It's sitting in my driveway, fending of mice and tires rotting out from under it as I don't have time or money to build it while I still have the eMiata. Can't seem to part with the eMiata, so contemplating selling the Alpine and all the bits I've gathered, but will likely not have time to build with. I have a new Warp 9, and a refurbished zilla, and some other stuff.... wanna buy it all?


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## clivepocock (Jul 8, 2019)

Hi Dan

That's very helpful and what a coincidence as we have a Miata as a second car !! Unfortunately we live in the UK and thus the expense of getting all those parts over would be prohibitive! I do have a holiday home in Sanibel but my wife would kill me if I accumulated hobbies there too!

Perhaps I can pop over and say Hi once I am back in Florida

Best regards
Clive


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## dtbaker (Jan 5, 2008)

The Miata is pretty much the modern Alpine.... cheap, fun, repairable...... the eMiata drives pretty much like the '66 Tiger I had torque-wise, but has far better suspension/steering/braking. I do love the look of the Alpine, but I am much more of a 'driver' than a 'restorer/collector', so converting the Alpine is making less sense as time goes by.

If you are ok with a low power, short range..... sticking with Alpine running gear, I would still recommend swapping out the tranny from a Miata, probably from '98 or newer. Part of the reason is that the motor/transmission adaptors for Miatas are available 'off the shelf' from CANev.com. Used/rebuilt Miata trannys are available cheap, and replacement parts like new clutch plate are easily available compared to retaining an old Alpine tranny.

If you intend to go on the smaller conservative side I would still recommend:

8" brushed motor ( ADC, or Netgain )
modern high capacity controller like Zilla 1k or Soliton Jr. , which can be dialed down so you don't break things
for simplicity I much prefer the large format prismatic LiFePO4 cells rather than reworking junked high-voltage packs from OEM evs. for a moderate build, I'd go with 120v nominal (38 cells) x 130ah cells.... something high quality like CALB.
consider constructing battery boxes from 1/4 sheet polypropylene, it is not too expensive, easy to work with, non conductive, and you can get some ideas from the pix on my website envirokarma.org as I showed construction of battery boxes.
I have great luck with NO reservoir for brake booster in the Miata, using an in line sensor, SS relay. If you stick w Alpine brakes, there is no booster required anyway.
other major tips that I will share, but many disagree with is I am a believer in top balancing Lithium batteries, letting the typical charger do it's job as designed, and periodically checking cells to make sure none are getting too high at the end of charge. The most important thing is the initial top balance BEFORE you use the pack charger.... Use a revolectrix or some other little programmable charger to bring each cell up to a known 'full' state (3.65v for LiFePO4), and then do a couple charge cycles.... check as the pack approaches end of charge, and drain a little energy from any cell that is above 3.70 to enable the rest of the pack to catch up and finish closer to theoretical average vpc.

With CALB LiFePO4, max recommended voltage and of charge is 3.65. I do initial cell balance to that, and periodically (like every 1000 miles), go thru the whole pack and re-top-balance to that. Then, I have pack charger set to end charge at theoretical average cell voltage of 3.50-3.55.... this give room for cells to drift a bit and stay within safe range until next balance.

The alternative is to add either a 'dumb' BMS that ends charge as soon as the first cell hits 3.65, or a smarter BMS that includes active shunting, and balances on the fly as cells hit 3.65.... something like the Orion or similar seem to be well developed now, but weren't available when I built my cars, and add over $1k in cost.

If you do get to Santa Fe, NM, USA.... give a ring, and I'd be happy to do a garage tour and talk details!


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## clivepocock (Jul 8, 2019)

thats great - thanks Dan ...small steps at the beginning of the journey!


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