# Planning 1968 Chevy Corvair



## Xrayguru (Jul 14, 2012)

Car weighs 1750lbs


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## EVEngineeer (Apr 11, 2012)

Hey sorry, I do not have any suggestions, since I have not built an EV yet myself, but to save the time I will ask you the questions the people who have not responded yet need to know.
What is your budget? What is your absolute max budget?

Here are some links to get you started with ideas on parts and stuff.
http://www.diyelectriccar.com/forums/showthread.php?t=73869
http://www.diyelectriccar.com/forums/showthread.php?p=304549
http://www.diyelectriccar.com/forums/showthread.php?t=8451
http://www.diyelectriccar.com/forums/showthread.php?t=75703

I do not know how much you know, but with AC the price is high and regen breaking is possible. With DC the price is much lower, but regenerative breaking in harder to achieve. Also, if you live on flat land regen breaking isn't worth it. Lucky for you though your range requirement is going to give you the option for cheaper Lead Acid batteries or for the high price of Lithium batteries.


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## TomA (Mar 26, 2009)

One nice thing about an electric motor is that it doesn't need 4 speeds. If you're on a budget, the Corvair guys hate the Saginaw 3 speed manual that came in early 'Vairs, and you might actually get one for free from somebody really into these cars, which is where you should also start looking for a differential and driveline parts. Yes, you'll want to keep all the stock stuff, unless you're a good fabricator and already have or can get workable components that will be cheaper than Corvair parts. That's pretty hard to do, though, as 'Vair parts are still cheap and work well.


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## TomA (Mar 26, 2009)

I've never seen a 1750lb Corvair. Corvair.com lists a '68 coupe at 2500lbs, and a complete motor at 310-325. Given you'll be dumping the battery, spare tire, jack, exhaust and fuel systems, your glider should be around 2050.


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## Xrayguru (Jul 14, 2012)

I can only go off of what the weight scale said. It was at a rock landscape place so it should be accurate scale. I have another corvair buddy looking at a 1980 corvette rear end for me tomorrow. The pictures look promising, just hope the frame and wheel base match up somewhat close. I want to direct couple the Dc motor to rear end and not have a transmission. Is that doable? I am green to EV but not to fabrication.


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## mizlplix (May 1, 2011)

Direct drive is a tough nut. Twin motors is a toughie also from a money standpoint. So would be putting a Vette rear suspension in a corvair.

My $.02.....

Corvair 3 speed transmission/suspension.
If you wanted an AC system, an AC50 kit.
If you wanted a DC system, a 9" motor/ Soliton Jr controller.

The heart of your car will really be the traction pack. 

Your 40 mile tripper/day is easily do-able. (Even lead/acid)

If you went DC, 3 speed, 100AH cells, 9" motor, I think you wouldnt be unhappy. (ok, AC50 too)

Remember, keep it light weight. It will be a nice car.

Miz


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## Xrayguru (Jul 14, 2012)

Thx for the info Miz. I have plenty of time to research as I will be restoring the body to perfect condition and then moving on to the drive train portion. Just wish I didn't need a transmission as I would rather not have a clutch and more moving parts added to the system. I don't know what kind of power a DC motor can put out from starting out to full speed going down the road without a transmission. Can one controller handle 2 DC motors?


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## TomA (Mar 26, 2009)

Xrayguru said:


> Car weighs 1750lbs


Understood, but what else is missing? The complete engine with gearbox and diff weighs 430-460lbs. If the half-shafts are gone, that's probably another 30+ lbs or more each, so something north of 500lbs is gone with the driveline. Is the interior complete? Got all the glass? Spare and jack?

If you're at 1750lbs, that's great, but you'll need to add back the things necessary to operate the car. Since you don't have the heavy half shafts, you can save some weight with aluminum replacements without thowing out perfectly good parts. If you don't have seats or they're shot, light racing buckets would save more weight. All in, I still think you're going to have over 2000lbs of glider in stock trim. If lots of parts are missing lighter replacements are not such an expensive upgrade. Drag racing seats would probably cost less than restoring a much heavier pair of Corvair front seats, for example.

I'm with Miz on the drivetrain. A Corvair is just too heavy to go direct drive without a big motor and very high amperage- and the transmision options are very good for your application. The Saginaw 3 speed is robust and has good enough synchros that, (provided you weren't intending to shift quickly or really go for the very quickest acceleration,) you could go clutchless, even with DC power- but drive somebody else's clutchless EV first if at all possible. Its not for everybody having to wait a couple of seconds to change gears. 

Anyway, time to talk about range. Let's say you can get it on the road at 2750lbs (Glider at 1950, motor, high and low voltage wiring, controller, adapter and charger all in at 225lbs, and batteries and boxes at 575lbs- which is 45 180Ah cells.) You could expect the car to consume 275Wh of energy per mile, probably a little more because its not particularly aerodynamic or small, and the stock bearings are hardly low-drag modern units. Call it 325Wh/mi worst case.

Anyway, your 45x180Ah pack is rated at 25,920Wh, of which you want to use only 80% regularly to maintain battery cycle life, so you'll have 20.7kWh full to empty. At 325Wh/mi, you'll have nearly 65 miles of range, and if you only actually use 275Wh/mi, you'll have an honest 75 mile range. 

That would make a dandy EV Corvair, but the components are going to cost nearly $16-18k, of which over $11k is batteries.


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## RE Farmer (Aug 8, 2009)

Another drivetrain to consider is the Powerglide (PG) automatic transmission. PGs for the corvair can be picked up quite cheaply as their not popular for circle racing as are the PGs such as Miz has in his. However, they are 2-speeds which can work well with EVs. Miz can give you info on running a PG w/o the torque converter thereby saving ~40# in the driveline.

Corvairs also are very light in front end (at least the early '60-64 ones) and might benefit from adding some battery weight in the relatively large front trunk. The very light, quick steering is one of the things that gave the 'vair a bad name.


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## onegreenev (May 18, 2012)

The Corvair is like the VW Bug. You have a transaxle so you really have no choice but to retain your original transmission. You can however have it re-geared to better suit a fat DC Series motor. The Corvair is heavy. 2500LBS. You do have a choice of transmissions. I am not fully sure how the trans attaches to the axle but it is not conventional. direct drive is not an option. 

Good choice. 

http://www.evalbum.com/3304/


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## mizlplix (May 1, 2011)

Electric motors have tremendous ability, but have some limits. Both AC and DC have those limits.

1-A motor alone without a transmission is a tough cookie to do. It needs the proper gearing, a large pack and excellent cooling. 

2-A motor alone can be geared for acceleration, but will have a low top speed because it runs out of RPM. It can be geared for cruise speed, but will draw a huge current getting there and will need good cooling.

3- Cars like the Tesla can be single speed because they are geared for decent acceleration and low current draw. They also can do 12,000RPMs to get a decent cruise speed. These motors are expensive.

EXAMPLE: My car has 7.80-1 in low and 6.14-1 in high gear. With a 32" tall tire gives me 55-60 in low and 105-110 in high gear. I can get by with this set up because of a good pack and my car weighs about 2,200#.

Yes, your car would be really cool with a powerglide. With the torque converter removed, a direct drive coupler made and an external charge pump installed, it would be unique.

Yes, you could use 1 large controller for two DC motors. But you would need a HUGE pack to support it and you would still have the gearing issue,(low current draw and low speed operation...or high current draw and decent cruise speed?)

YES, direct drive is possible by replacing the trans with a I.R.S. type diff. (corvette) and retaining the corvair suspension. But, not desirable in My opinion.

Miz


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## CrazyAl (May 9, 2011)

Xrayguru said:


> Hello all.
> 
> I am picking up a 68 Corvair this weekend and it currently has no drive train what so ever. I thought electric would be a great way to go. It is a rear wheel driven car and the motor is normally in the rear. I am not sure if I should go two motors in the back independent or connected or just one. Does it need a rear end? Transmission? Would like some ideas from some people on what they would do. My range would need to be a minimum of 40 miles which is round trip to work. I am good at electrical wiring and mechanical. Good at fabrication also. Was thinking of using an AC motor and possibly regenerative braking if possible. Other than that I am not sure what else would be a good fit for my project. The car stock weight is 2500lbs roughly but with all drivetrain out I am estimating it to weigh 1900 pounds. Any suggestions anyone???


Have you considered an Emrax Motor? Very light weight at 26lbs,
Peak power (1 minute) is 80kw which is 108 hp.
Power (2 minutes) is 50kw which is 68hp.
Continuous power is 30kw which is 40.8hp.
Exterior dimensions is like less than 4" in length and it is less than 10" in diameter.
More details at http://www.enstroj.si/Electric-products/emrax-motors.html

It is an AC motor so can have regenerative braking (if controller supports it). Someone in my Electric Car Club bought a few of these motors and they are quite compact.


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## TomA (Mar 26, 2009)

mizlplix said:


> EXAMPLE: My car has 7.80-1 in low and 6.14-1 in high gear. With a 32" tall tire gives me 55-60 in low and 105-110 in high gear.
> Miz


Not to go off topic, but are you sure about that low gear ratio, Miz?

If you have a 1.82:1 1st in your glide, that's 11.17 final in low, which would line up better with your reported speeds in gears.

Just guessing, but I don't think a 1.82 first PG/3.89 rear is deep enough gearing for this heavy a car, which would be only a 7.35:1 final drive in low. To go deeper is going to cost real money for non-standard ratios, where the stock Saginaw 3sp is cheap and offers a better spread with the deepest stock differential.

Since the Corvair is going to be at least 50% heavier than your A-bone, the Saginaw 3 speed is probably a better spread with the deepest 3.89 Corvair diff. I'm not sure what ratios are now available for the Corvair 3 speed used, (stock spread was 3.50/1.99/1) but that stock box combined with the optional stock deep diff (versus the more common 3.27 or 3.55) would provide three apparently useful drive ratios, (13.61:1, 7.74:1 and 3.89:1) especially with the stock tire height of 24.5". The more common and cheaper 3.55 Corvair differential gears might be an even better choice...


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## Xrayguru (Jul 14, 2012)

I have been reading up on the PG and would like to use that. Not having a torque converter sounds interesting. I would like more info on that if you have it. I also want to machine up some aluminum half shafts to lighten things up a bit. I also heard you can get the rear and front hood in fiberglass which would also help on weight. what DC motor would be a good fit for the PG/Corvair?


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## Xrayguru (Jul 14, 2012)

If I was going to do the corvette rear it would have been with the suspension as I would gain disc brakes. Do you have a design for using a DC motor direct coupled with the PG? Is there such a thing as an external charge pump? That would have the same effect as a torque converter? Miz do you have a Corvair project?


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## TomA (Mar 26, 2009)

Xrayguru, you would really benefit from reading Miz' build thread:

http://www.diyelectriccar.com/forums/showthread.php/1930-model-roadster-build-59659.html

It might take you a couple of days, but its a terrific example of a carefully planned and executed build, and what happens along the way.

You need more people to weigh in on gearing, but I just don't think the Powerglide is going to work for you, because you can't get sufficiently deep gears for the differential. 

Looking into it a little, there's more to the Saginaw 3 speeds in these cars than I thought. The early ones with the deep first gear don't have first gear synchros, so you are going to have to figure some things out, but there are choices. Join corsa.org and check out their forums. You'll get lots of help on everything from parts selection and sourcing to shedding weight there. BTW, their international meet is in Sturbridge, MA in two weeks.


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## Xrayguru (Jul 14, 2012)

I have read all of Miz's thread and would like to say he has done a wonderful job and shows that anything is possible with time and money. Not forgetting determination. I did learn quite a bit from his epilogue and know also from him doing his project there is some things you just have to do for yourself in person to get the answer/results you need. I first will be contacting my insurance agency to see if I can get insured. That will be my defining green light. I then will complete the body and find a rear differential and power glide. Hopefully that all will be done by next year and then see what options best fit my needs. I would like to pull the max range out of my car but would settle for a work commuter.


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## TomA (Mar 26, 2009)

I think if you go with a stock PG and any stock diff, your drive ratios will be 7:08 in low and 3.89:1 in high, or 6.46 in low and 3.55 in high, all of which is really too tall, but I'll stop saying it now. 

To make that work well in a car over 2500lbs that seats 5, you're probably going to need an 11" motor, 1400-2000A liquid cooled controller, and a big turbo blower to cool the motor. Even 200Ah prismatic cells will be overstressed at the amperages you'll routinely see, so you'll have to supplement them with some A123 cells to absorb the transient current loads. Everything is getting heavier fast because of the high amperage requirement, aggravating the problem, and multiplying the costs.

You'll also be making some monster torque in this configuration, stressing your direct-driven nested 'vair PG input shafts, which may not be up to it, particularly if you don't seriously slow the rate of power onset in the controller. Lastly, since you won't have any damping between the motor and the transmission, road shock (like wheel hop while going over a shabby rail road crossing under brisk acceleration) may well snap the transmission shafts when fully laden.

Enough of my precautionary concerns! Everybody should build what they want, by all means, and with the right amount of care and money it could work well- even the hard way. More and deeper gears would be so much easier, though...


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## TomA (Mar 26, 2009)

Sorry, that was a lot of conclusions without any reasoning. Here's what I really mean:

The torque converter in the Powerglide isn't just a fluid clutch, its also torque multiplier. That's why the 'glide can use taller and fewer gears with the same motors as other stock Corvairs. When you remove the torque converter, you now need to generate a lot more torque in the motor to get the same performance.

The transmission isn't designed to accept that much torque without the dampening effect of the fluid clutch, (TC) so its input shaft will be stressed much more by the higher, and especially the instantaneous torque your electric motor dishes out, both when you stomp on the throttle and from transient on-off traction situations.

The Powerglide is a neat EV transmission, but it isn't a panacea, and with the compromised input system of the Corvair configuration, in a heavy car with a relatively tall differential, I don't think its a good choice.


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## mizlplix (May 1, 2011)

For this car, I still stick to my very first post on page 1.


> My $.02.....
> 
> Corvair 3 speed transmission/suspension.
> If you wanted an AC system, an AC50 kit.
> ...


Either with a clutch or clutchless, depending on the drivers needs.

I like a clutch with a cut-down flywheel. I have owned two door slammers/clutch/lead -acid. They were both daily drivers about 3,000# and got about 40 flat land miles per charge and with new batteries could do 65MPH. The batteries eventually tapered off after a couple of years to half that. I had driven about 15,000 miles by then.

I should expect the same from your car.

Internet speculation is just that and is good for intellectual stimulation, Real-world, Hands on experience is just that also (Providing you trust the supplier)

Good luck with your car, it sounds like a good project.

Miz


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## Xrayguru (Jul 14, 2012)

Trying to attach a picture of the car. we shall see if it posts.


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## mizlplix (May 1, 2011)

I always thought of those as Mini Camaros...Lol

I used to have a 1963 Spider rag top.(I have a long list of ustas)

Your car will be doubly satisfactory because of all the extra body and resto work.

Miz


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## Xrayguru (Jul 14, 2012)

That's my bigger little brother in the picture helping me. He has never hauled a car before. Miz I believe the camaro got it looks originally from the Corvair body style. 
So I have some specs to share from my research. My overal tire size height wise will be around 24". 

The rear end I have three ratios to choose from (3.27:1) (3.55:1) (3.89:1). 

The Power glide ratios are low gear (1.82:1) and high gear (1:1)
Stall on torque converter is (2.6:1)

The original motor specs are [email protected] rpm and [email protected]

I am not a mathematical genius so with all that I am unsure if I need the PG or direct drive is still feasible. I want to keep that height of tire for good stability and looks. 

Miz you have proven to have RL advice and I trust your opinions. How does one go about matching up an electric motor with enough umph to match what the ice motor did or better?


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## mizlplix (May 1, 2011)

Xray: First of all your requirements are determined by where you live. Hills, heat/cold, average daily milage needs.

On paper, a warp 9/soliton controller,3.89 gear, 24" tire, adequate pack size, looks really good, with a 3 speed transmission. It would MPH out at about 100 or so in 3rd gear at the motor max. RPM. 

Go here to try combos: http://www.rocky-road.com/calculator.html

As stated, I like a clutch. (others do not) Try to drive a stick shift trans a little without using the clutch. Start out with clutch, accelerate, off throttle-press shifter gently, it will go to neutral, press gently, it will go to second with a 2-3 second lag. 

Your pack size requires more info. go here and read at bottom of page.
http://www.evolveelectrics.com/Netgain Motors.html?gclid=CIWUvcuAorECFSUbQgodr279jA

More later.

Miz


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## Mark C (Jun 25, 2010)

Subscribing. 

I love the second generation Corvair coupe body style. Yours looks to be a nice example to restore. It was great your finding a '68 {'69 is good too, but harder to find} as I prefer the added standard safety features that started appearing in the late '60s. By '68 all were required to have dual reservoir brake master cylinders, energy absorbing steering columns and shoulder belts. Having survived some stupidity {aka car "accidents"}, I kind of like some safety equipment on board. 

Sorry I don't have any EV building experience to offer, but I was thinking Warp 9 HV and Soliton Jr would make a sweet combo.


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## TomA (Mar 26, 2009)

mizlplix said:


> As stated, I like a clutch. (others do not) Try to drive a stick shift trans a little without using the clutch. Start out with clutch, accelerate, off throttle-press shifter gently, it will go to neutral, press gently, it will go to second with a 2-3 second lag.
> 
> Miz


Also, keep in mind that an electric motor is both easier to shift clutchless, and easier on the synchros over time. That's because an electric motor has less rotational mass than an ICE, and no pumping resistance to overcome, resulting in far lower resistance for the synchros to overcome as they equalize the shaft speeds inside the transmission.

It still takes time, though, and 2 seconds is a long time to wait for the shifter to fall into place if you aren't used to it and planning ahead.

Also, if you delete the clutch, its critically important that you get a later Saginaw Corvair 3 speed with synchromesh gears on all 3 speeds, not one of the earlier units with synchros only on second and third gears. You'll only be able to downshift an early gearbox into first at rest without grinding it, making it unsuitable for clutchless operation.

With a DC motor, a clutch is also a safety feature, as DC controllers can fail shorted, which results in full power that can't be turned off. If you can't pull in the clutch, you'll have to break the high voltage circuit under max current to stop the car. You should of course have a system (contactor, "Oh, Scheisse" switch, etc.) to do that anyway, but the clutch is actually more reliable and easier to think of in an emergency. AC controllers don't fail in full power mode, so its not an issue is you go AC. 

Lastly, I don't think the Soltion Jr. (or Curtis) controller is going to be satisfactory with a curb weight over 2600lbs, and a gross weight well over 3000 loaded. The extra 50% more current of a Soliton 1 is going to be very useful getting your car moving. Once you go to 1000A, you'll be much better off with 180Ah cells, which won't be nearly as stressed or sag as much as 100Ah cells at the current the Soliton 1 can draw. (5.5C versus 10C with 100Ah cells.) If you want anything like stock performance, 650A is going to feel slow.


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## hjackson3149 (Aug 29, 2012)

Good morning all

I to am planning a corvair conversion with a PG tranny
mine is a 69 moza
the information I have found about the diff ratios is that
there are several available

3.08, 3.27, 3.55, 3.89 and 4.11
also the PG diff can be made into a possi unit

I am planning to use
1) warp9 motor @ 144v
2) soliton1 contoller
3) Calb cells 48 @ 70ah (second pack to be added)
4) existing 12v system and battery at first
will DC/DC converter if deemed nessasary

I plan on starting with the installed 3.55 and see what happens

if need be then will make changes, or possibly goto a manual

also I plan to idle mine for simplicty's sake and possible A/C

mine is currently running and it runs real well for testing

will be following this thread intensly, and will start my own as soon as I get to the purchasing stage

any and all comments and suggestions are much appreciated

thanks
Hank
in south fla.


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## mitchhodge (Oct 1, 2021)

Hi, just joined this forum. the electric motor and gearbox appear to be an ideal fit for VW/Corvair engine/transaxle replacement. Simply put, they both connect to axles out each side. I'm researching converting my 63 Rampside to electric so any input is appreciated.


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## remy_martian (Feb 4, 2019)

You can pretty much ignore everything in this thread as the choices now, vs what was available in 2012, make it all pretty much obsolete.


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