The "right" Transaxle

[Russ Noble]

If you opt to go the used route, there's the Audi 016 5 speed which is marginal at the power levels you are discussing (although some people swear they can handle 450hp with ease). Cost on these vary but are typically under 500 bucks.

Here you have the various flavors of used Audi gearboxes, the 01E, 0A2, 01X etc.
The only gearboxes I'd recommend for 400hp and up are the 0A2 or 01E.

There's the upgraded and re-manufactured 5/6 speed Audi 01E's, which start at the mid 2G's and up.

3K and up is your used Porsche gearboxes in various configurations.

Ken,

Just be aware that contrary to all the other trans mentioned the Audi must be fitted with the input shaft above the driveshaft line since it can't be inverted. Hence you have an undesirably high engine position. For a low priced option the Renault is maybe a better proposition.

 

[ken1939]

Truthful and to the point lol. Well that and sorting out this long box business which I think I get. Based on what I am reading I think the G50, 1988 to 94 version seems to still be the best direction for me.. The Colt 45 vs the Luger argument.

Heck a Ford guy I know is says the 302 would be nice, but a big block or a modern cammer would be even better. I think he does not understand the space restrictions we are dealing with here, and well the 302 will be potent enough with todays technology to get 400 out of it.

One thing for sure, I do love the learning curve.

Sometimes all the work, fabrication, and figuring out the problems are most of the fun in doing any car. Once you are past that, sometimes "just" driving them is well soso. The how of execution I guess.

My advice would be to do exactly what you have said but sorta tongue in cheek. Spend twice the money on the remaining power train than what you spend on the motor itself.

$10K on power train and $5K on the motor is a good starting point. No matter what you decide install or choose a box with a limited slip. I believe that a proper LSD is the most important performance option you can put in a GT40. They are right up there with very good brakes in my opinion.

I know this sounds a little extreme but I assure you that if you do the gearbox right the first time you won't be re-engineering the car later to change the gearbox type. Mid engine cars ARE THE GEARBOX! No fun with a bad one and better than sex with a good one. I like a G50, Quaife TBD, taller 1st and 2nd gear and stronger side-plate. But this is not to say it is BETTER than a ZFQ or some of the others. It's more the availability and service ease for me that anything else. Lots of people in the US to help you with parts and a few good re-builders spread out across the US.

Put it behind a 350HP 302 and sort it all out. Adding more power on the other hand is really pretty easy. Later you can put in another 100HP when you feel the need and the rest of the car will be ready for it.

 

[Erik]

Answer for Jac Mac: I will have to look into the options available for the ZFQ with regard to a plate-type ramping differential. I am not sure yet what is currently available.

You bring up a good point, but it should be noted that the reason for my like of the LSD vs the TBD made by quaife is not in the craftmanship, it is simply in the operation. I like that the LSD offers lock up on the Decel side of things. It is normally the preference for racing applications, however, it is really a judgment call that varies from driver to driver. I am sure you have seen many people here who love the Torque Biased Option and would actually prefer this to the sometimes more expensive LSD options that are out there.

Howard: I could not agree with you more. If you are going to build a really specialized car, you should do the gearbox correctly the first time around. Get one that will more then handle the HP and Torque that you wish to run, that way if you decide at a later date to up the anti on your engine, you will not have to worry about the gearbox being able to handle the additional Hp and Torque. Budget is always a concern, but I will echo your post here and recommend that you not cut corners with regard to the gearbox, you will almost always pay for that mistake in the future, often times it will cost more then if you would have made the jump first time out.

Great Posts on this subject. Let me know if I can help answer anything else.

Warmest Regards, and happy building

Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell

 

[flatchat(Chris)]

I have to agree with Howard and Eric in this lot :thumbsup:

Once again -- I've seen more broken (Ford) motors than G50s

 

[ken1939]

Have to say it one more time, a truly helpful and informative thread! Not one that ran in circles.