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Discussion Starter #1
Hello all,
I have been wanting to build an electric car for a long time and have been putting it off. Well now is the time but I need some guidance. I have a 1972 Cutlass that used to be my ever day driver up until 2013. I couldn't justify destroying the planet to drive that old car. But then I saw the Tesla model s and its whopping 4000 lbs go from 0-60 in just a few seconds. I want to convert the Cutlass into an electric. I know its an extremely heavy car which means more cost but it will be my everyday driver when I'm done so I might as well think of it as a new car payment. My first questions is, would a muncie 4 speed be a good transmission for an electric motor?
 

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Hi
Your best bet is to get a crashed electric car and try to use all of the bits

Including the motor/transmission unit
 

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I want to convert the Cutlass into an electric. I know its an extremely heavy car which means more cost but it will be my everyday driver when I'm done so I might as well think of it as a new car payment.
The Tesla Model S is heavy because it has a heavy motor and a huge battery. It isn't even heavier because it has an aluminum unibody designed specifically for the battery. A 1972 Cutlass is a car, too... and that's all it has in common. Realistically, what are your performance (acceleration, range) targets? They will need to be far short of Tesla Model S performance.

I hope that you realize that a new car payment is what the project will likely cost each month, for the year or two that it takes to do the conversion.

My first questions is, would a muncie 4 speed be a good transmission for an electric motor?
First you would need to decide on your layout of engine, transmission, and final drive (differential). If you choose to keep the car's original layout - just replacing the engine with an electric motor connected to a transmission in the stock location and a lot of battery - then the Muncie would probably work fine: manual is preferred, four speeds is enough, and any transmission used with the 455 engine would be strong enough for any reasonable electric conversion.

Your best bet is to get a crashed electric car and try to use all of the bits

Including the motor/transmission unit
Generally a great idea... but in a Cutlass? Given the rear-wheel-drive and live beam rear axle, using any production EV drive unit would mean a complete replacement of the rear suspension and major modification of the rear floor of the body. It's possible, but unreasonable for most DIY builders, let alone a first-timer.
 

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Discussion Starter #4
I originally though about taking a Tesla model S and attaching the sub-frame to the rear of my cutlass but the frames don't line up quite right and I don't have enough experience to fabricate that sort of connection. I want to go with something a bit simpler, though its still going to be pretty complex.

That's true, the Tesla's battery pack alone weighs 1200lbs. But removing the engine, exhaust, gas tank, automatic transmission(slightly heavier than a manual), the coolant system, and any other odds and ends will lighten the load to about 2500 lbs start out. And I want to go with a couple 120 lb motors, though I'm having trouble finding a quality forklift motor near me.

My thoughts on the drive system is to keep it as close to original as possible so leave it a rear wheel drive car with a manual tranny and two dc forklift motors in the engine bay surrounded by batteries. The other batteries will go in the trunk and where the gas tank currently resides. My car is currently an automatic but I want it to be a manual and I know that works better for electrics anyway.

Thank you for your thoughts!
 

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Might be worth comparing the dimensions of your transmission tunnel with the transmission of a Lexus GS Hybrid (or the equivalent Camry). These are RWD and have two motors built-in, totalling about 400bhp, which is probably slightly or plenty more than the stock V8, and may have better low-end torque.

You can use the stock Toyota/Lexus power electronics:
https://openinverter.org/forum/viewtopic.php?f=14&t=205

Here's Damien (username Jack Bauer) using this powertrain in a BMW 7-series: https://openinverter.org/forum/viewtopic.php?f=11&t=96

If you can fit the GS gearbox far enough back, you should be able to hit a good weight distribution with your battery pack split between the rear of the engine bay and the space where the 20 Gal. fuel tank was.

This idea should let you keep the car's original suspension, you'll just need a new driveshaft and some custom gearbox mounts.
 

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Using two forklift motors is a good idea - but with a heavy car like that you will want two 11 inch motors - and they are about 220 lbs each not 130 lbs
 

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Discussion Starter #7
Oh wow, I didn't realize how heavy a forklift motor was. I'm having trouble finding information on old forklift specifications. I found an old electric clark but the guy doesn't know anything about it except that it is heavy. I also found an old yale electric but they also don't know anything about it. And I found a couple 40hp GE motor but it looks huge and they said its rpms are 1750. But no specs on if it's an ac or dc motor.
 

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In the "Electric Motors" section there is a long thread about using a forklift motor - I know it's long and a bit repetitive but it's worth going through it first before wasting time and money
 

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Discussion Starter #9
I read the thread and it did offer alot of good information. It look like I will be needing either a 9" or an 11" motor. For what I want I think 2 11" will work best due the the massive weight of my car plus batteries. Something I am wondering, and this is probably a dumb question, but when referring to a 9" or 11" motor, does that number represent the length of the motor or diameter of the motor? Its hard to judge based on photos with no scale.
 

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It's the diameter

My 11 inch Hitachi is 11 inches in diameter and about 14 inches long - and 103 Kg
 
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