Caffeine-induced transaxle idea

[Eric]

This is probably a hare-brained idea generated by too little sleep and too much caffeine, but here it goes. Why couldn't you take a differential out of a RWD car with independent suspension (say a Corvette) and an American manual transmission, marry the two, and make your own transaxle? To oversimplify the idea, take the tailhousing off of the transmission, take the front off of the differential, put the pinion on the output shaft of the transmission, and fabricate a coupler to mate the two housings. Obviously, there is a bit of engineering here, like perhaps shortening the transmission output shaft and figuring out a way to put the pinion on it, but I can't think of a reason the theory is unsound.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
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Why would you do this? After spending hours reading through the threads in this transaxle forum, there seems to be more or less a general consensus that the European transaxles have gearing more suited for smaller engines, not V8s, and in many cases need to be upgraded to handle the higher horsepower/torque applications. Additionally, it also seems clear the supply of these boxes is dwindling (and prices increasing). The above idea allows you to take a transmission geared for a V8 and marry it to a differential geared for a V8. Additionally, you can go to the boneyard and pick up an American manual transmission for a couple hundred bucks (USD) and a complete independent suspension for a couple hundred more. Even if you ended up spending $3K or $4K on the whole conversion, you'd still be ahead of the game with the gearing and that would be less money than upgrading a European transaxle. Plus, a Ford transmission and clutch assembly bolts right up to a Ford engine, a Chevy to a Chevy, you get the idea. The aftermarket for performance parts, at least here in the U.S., is nearly unlimited for U.S. transmissions.
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This idea seems so basic, I'm sure I'm not the first one to think of it. So, why has this not been tried? If it has, why has it not caught on?<o></o>
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All thoughts are welcome.<o></o>
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Eric

 

[Bram Boekestein]

It has been tried : http://www.gt40s.com/forum/gt40-tech-powertrain-transaxles/28921-850-qc-transaxle.html

You say 3k or 4k, for that you have g50's, 930's etc. even reconditioned if you're lucky. A Audi box with LSD and gearing to suit is also in your budget, even cheaper. I live in europe so audi's are easy to get for me a few hundred buck's.

Why go through all that trouble and have something you don't want? The diff will be behind the gearbox according to your story, this is very unpractical for use in gt40's and other mid-engine users. The wheelbase will increase by approx the length of the whole assembly. Something like this with the diff in-front of the gearbox could be interesting, but this will be 100 times more complicated to fabicate.

Bram

 

[Lynn Erickson]

Already been done. they used a corvette engine with C5/C6 transaxle without the drive shaft in between. these have been used in some mid engine drag cars/ wheel standers. In a mid-engined sports car the engine would be about 18" further forward then with a normal transaxle.

 

[Ian Anderson]

Eric

I would think that your Engine / gearbox / diff unit wold pt the driveshafts to far rear for a GT40

It has been done though - doa search for the Giant
It used that type of design then kevlar belts transferred the power back towards the front of the vehicle to get the drive shafts at a better angle

See
http://www.gt40s.com/forum/gt40-build-logs/16306-progress-giant-one-off-large-gt40.html


Ian

 

[Russ Noble]

This idea seems so basic, I'm sure I'm not the first one to think of it. So, why has this not been tried? If it has, why has it not caught on?<o></o>
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All thoughts are welcome.<o></o>
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Eric

That's what the T44 was! But in a suitable configuration with the diff ahead of the gearbox and all combined in a new housing.

It was used in the Mk2s and Mk4s and Jcars. A Ford 9" diff mated to a toploader through a set of drop gears.

I think they are still available if you've got the dollars, but apparently the price makes the Euro transaxles look cheap!

Several people on this board have tried/are trying to build something similar. Some are well documented on here. See for instance the TRT thread.

Some are alluded to in peoples signatures, keep an eagle eye open. There is a guy quietly beavering away at one now. But with too much attention his signature might change!

 

[Eric]

Thanks for the replies. I knew I couldn't have been the first person to think of this. The only stumbling block that I could see would be the length and, indeed, that does seem to be the issue, at least as far as a GT40 is concerned. Still, it would open up some interesting possiblities, as I alluded to earlier.

Eric

 

[Jac Mac]

If Caffiene wont do it RUM might! As an indication since the pic attached was taken those patterns have probably absorbed another 30 odd hours of 'fudging'.

 

[Russ Noble]

Some are alluded to in peoples signatures, keep an eagle eye open. There is a guy quietly beavering away at one now. But with too much attention his signature might change!

Hmmm..... that didn't take long!

 

[wanni]

if i answer i am accused

 

[BruceA]

If Caffiene wont do it RUM might! As an indication since the pic attached was taken those patterns have probably absorbed another 30 odd hours of 'fudging'.

Jac, are you tempering the woodwork with the woodfire??

Ohh, and Wanni, nice to see you again - your thoughts and experiences always appreciated.

 

[Russ Noble]

Wanni,

Maybe..... Don't worry about the wowsers! Good to see you back :thumbsup:

I always enjoy your tech, although sometimes it loses a little in the translation. Nevertheless your English is miles better than my Italian so full credit to you.

 

[Jac Mac]

Jac, are you tempering the woodwork with the woodfire??

Ohh, and Wanni, nice to see you again - your thoughts and experiences always appreciated.

Rambo, nope, trying to make the 'poxy' epoxy go 'off' quicker! & there have been times when the whole shebang has been close to going in the woodfire.

Say what you like Wanni, Us Kiwis have thick hides & selective deafness at our disposal.

 

[Russ Noble]

Say what you like Wanni, Us Kiwis have thick hides & selective deafness at our disposal.

Why is it that only Kiwis have shown support for Wanni on this thread?

Maybe we're more laid back than the rest of the world.... Ross Nicol certainly is!!

Go Wanni!!

 

[Bram Boekestein]

Support from europe to!

 

[roaldin]

Go for it Wanni! (hope that translates properly!)


Tim from Aus'.