# Planning Chevrolet Caprice Classic Conversion



## KrisWood (Apr 24, 2009)

Hi everyone! My father today gave me the old caprice classic wagon (1987 I think) that's been sitting in the garage since he bought it. He only starts it up once every few weeks to make sure it still does start up and back down and up the driveway. Now that it's mine I can't help but think that the thing's a tank and is going to drink a LOT of gas! That got me to thinking, why not electric?

The main thing I'm trying to find out now is how much a conversion costs, because if it's more than the cost of a new car I don't think I'll have the funds (or want to dump them on this particular car) to go through with such a project.

That said, here's the info the sticky said I should put here


I am moderately skilled with auto mechanics and fabrication.
I will not be using more than 30 miles a day with this vehicle, but more is always nice.
Level of performance: Point A to point B without needing to be towed back to point A.
How much money you are willing to put into your project: As little as possible, no more than a few thousand but preferably under a thousand if possible.
Parts? It needs battery and a motor, beyond that (including which ones will work for me) I'm clueless
Please have mercy on my noob-ness! Thanks! 

Edit: after reading through the forums searching for cars like mine I've discovered a few things:

1: Yes it's possible to use the current automatic transmission but it's a lot of work and inefficient
2: This is a VERY heavy car and will not perform well as an EV. That said since it's mine now I'm perfectly happy to strip it down to the frame to get better performance out of it.
3: I neither need to go fast nor far, simply safely. The farthest destination I am likely to visit is my uncle's farm 13 miles away and I can plug in there. I also don't need a lot of power as long as I can accelerate safely enough to get into the slow lane on the freeway.

So what it all comes down to is, can this be done on the cheap? What is the bare minimum to get 30mph and 30 miles total range?


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## ZeroGasoline (Jul 30, 2008)

KrisWood,

You will have a very difficult time trying to accomplish what you're looking for on such a budget. The Caprice is a very large, very heavy car. The larger and heavier the car, the more expensive it becomes to convert it to an EV - if you have to push more weight around, it takes more energy and more energy means more batteries and more expensive electronic components.

My conversion:
94 Tercel
1950lbs pre-conversion (roughly the same post conversion)
Top speed 55mph
Range 20 miles on a good day
Total cost: ~$5500

Search Google for "forkenswift". I forget the mans name but he did a conversion for under $1000. Again, he converted a Geo Metro and I don't believe he ended up with the performance that you're looking for, but a low cost EV can certainly be had.

If you can get a hold of a smaller, lighter car you might be able to make it happen (if you are creative, like the forkenswift project).


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## KrisWood (Apr 24, 2009)

Thanks for the reply! I was coming to the same conclusion after further research. I'm better off leaving the caprice as a gas guzzler and saving up for the EV project. I used to own a metro, was my favourite of all the cars I've had actually, maybe I'll get one again.


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## argo (Jan 3, 2013)

I know I am a little late to this discussion (ok, half a decade) but I wanted to see whatever happened to the wagon? There are options for increasing efficiency beyond electric conversion that would work well on these cars, but all require work. As a huge fan of full size wagons(esp the Caprice) I think it is worth it.

The first thing to do is tune it up. The Olds 307 under your hood (the Olds engine was used in all GM full size wagons from 86-90) is actually capable of decent efficiency if it is running right. Also, replace all 10 miles of vacuum lines to ensure the engine and the carburetor function correctly. A full tuneup with plugs, wires, all filters, PCV, and a 205* thermostat (factory is 190*) will improve it from being a full on gas guzzler to just a heavy drinker. But we are not done yet.

The O2 sensor on this car is cheap and easy to replace. That is good. The sensor costs about $30-$40. It becomes ineffective after about 30,000 miles however so it should be changed when you tune up the car. This will reduce it from a heavy drinker to a moderate drinker.

Tires are critical as well. Get a set of low rolling resistance LT tires with a high pressure capability. I use Yokohama Geolander HTS tires on my 1992 Caprice Wagon (mine is an EFI 305 powered car) in the LT-215-75R15 size and pump them up to 51 PSI. This improved my fuel economy by 1 full MPG on the highway. 

Back when I had my 89 caprice wagon it would get 23 MPG highway without LRR tires, so 1 more Mpg would have improved it to significantly better than a 2wd SUV with similar capabilities. 

Now that we have done the easy stuff, let's get into more complicated territory. Chances are the carburetor is in need of attention. The carburetor has probably seen better days. A good rebuild will net you several mph if the carb is malfunctioning even if the car runs well. That said, the electronic quadrajet is an intimidating piece of hardware to mess with. 

I have not done this personally but there are many Oldsmobile fans who have converted their carb equipped 307s to TBI. If you use a Chevy 305 (RPO code LO3) system it will work easilly and net you more efficiency than a carb rebuild and much better efficiency. The only problem is these computers will lock the torque converter clutch on your 200-4R transmission almost all the time so a toggle switch on the dash to kill the circuit around town will be needed to avoid lugging the engine.

Of course a diesel conversion (6.2L GM diesel) will help you get over 30 MPG. I converted a 1993 2wd suburban with an aftermarket computer for the transmission and a custom built 6.2 that I tuned for maximum efficiency and it will get 27.5 MPG at 60MPH on the highway with 4 bikes on a carrier mounted to the hitch, a week's worth of luggage for 2 adults and 4 children, a dog and travel crate, 4 child safety seats, and a week's worth of groceries in coolers. In a car 2000 lbs lighter and more aerodynamic and a taller rear axle ratio 30 Mpg should be no sweat. 

Now please don't everyone try to shoot me. I know this wasn't about an electric conversion, but as a fan of these cars and a fan of efficiency (electric or not), I wanted to share how to make these cars not be nearly as bad as their undeserved reputation. They are much more efficient that SUVs. It amazes me when I am driving my 92 Caprice Wagon how many people in Suburbans and Excursions and Tahoes and Durangos comment on how much gas my car must use. It is no Prius but it gets 26 mpg on the highway (26.2 round trip from Dover DE to Disney World and back at 70 mph with the air conditioner on in June). In fact, it did 1/2 mpg better than my brother's 2012 Honda Oddessey, much to his dismay (he hates my "grandpa car").


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## timk225 (Sep 19, 2014)

Holy thread necro, batman! April 2009 to yesterday? The OP hasn't even been here since 2011!


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## argo (Jan 3, 2013)

I know, I know! I just wanted to see how the car turned out. I keep trying to talk Elon Musk into giving me a Model S drivetrain and battery to convert my 1992 Caprice and co-develop an "electromod" kit (in reference to the "resto-mod" nomenclature used when discussing putting modern components into older cars). So far he hasn't responded... but I keep hoping to get a response!

Sorry for "Frankensteining" this thread... I have a soft spot for these cars and I was curious about what ever happened to it.

Well, back to the crypt with you, I suppose.


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## janimani (Nov 11, 2014)

Nice work.. Did you test the car yet ?
What batteries are you planning on using ? Did you decide on a controller yet ?


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