Which kit should I choose?

[Mike Dozier]

Johan

Goran's work looks very nice....and local manufacture/support is always a big plus.
You have our permission to buy one !

The ZF trans used in GT40s usually come from Panteras,
but they are not easy to find and somewhat expensive.
However they certainly look nice for originality.
You can buy a new one from RBT in the US ($$$).

I understand the BMW M1 also used a ZF...but there are differences. The boys in the UK should have the details.

Many GT40 owners believe the Porsche G50 is a better box
for replica use since it's cheaper (than the ZF),
much more available, has large aftermarket support,
and has proven it can handle 500 hp if set up properly.
The Porsche 930 can also do the job...but it's 4-speed
and may not be quite as flexible as a dual purpose trans
as the G50.
Regards

MikeD

 

[Johan]

What about an old Olds Tornado (???) gearbox then? I don't think i'll find one here, but in the states there should be a fai amount of them! /ubbthreads/images/graemlins/smile.gif If i remeber correctly, that car came with a BB in the sixties? And it was the first (???), if I remeber correctly, FWD car at that time with FWD in the USA!?

Could atleast be something for the americans here /ubbthreads/images/graemlins/smile.gif

Another question, does anyone here have any exoerience or info about the tranny in the Porche 928? The 928 has the gearbox in the back sitting like a transaxle box, the car produces 300bhp stock and it should have an LSD stock i think... Also it's not that expensive!

 

[Howard Jones]

Olds, Huge weight and lots of engineering to fit it in. Porche 928, big problem with fitting a bellhousing to the front of the gearbox. The 928 had the clutch and bellhousing on the back of the motor up front and the gearbox/diff in the back. Again lots of engineering to make it work.

I supect both of these ideas would cost more than a "standard" G50XX setup to do and many times more than a Audi.

 

[Andy Besic]

A guy by me has a toronado BB in the back of a McClaren replica. Fits fine but the car has a 20% front 80%rear weight distribution. It goes like stink in a straight line and has a great launch but it won't stop or turn.

 

[Rune]

Use the Audi transaxle from a A6 95-97 2.5 diesel ARX it is lots of them in Sweden .and do You intend to race that hard ? The engine sits a few cm higher so what? The transaxle cost next to nothing between 1000-5000 swedish krones You can change wheels rear to a wider type , You can go for lower profile on tires to compensate. Am I right when say that most use will be on road and normal speed ?.

 

[Johan]

Most use will be on the road, tes bune /ubbthreads/images/graemlins/wink.gif But I still want a top speed over 300kmh! Is the Audi transaxle geared for that?

 

[Mike Dozier]

The stock Audi 016 is not geared for high top speed.

In the Transaxle section of the Forum you'll find a thread
by Mitch which discusses a new final drive gear set developed by German Transaxle of America which allows
a much higher top speed.

I'm not familiar with the A6 trans mentioned above...
it if has a different casing than Audi model 016 or 01E,
you'll have to have a special adapter plate made.

MikeD

 

[Bill Hara]

Guys
Have a look at the document I have attached (it is compressed), it is a combination of gear ratio speed calculator and Mark Worthington's audi gearbox info. It will allow you to calculate in-gear speeds for any RPM and wheel/tire ratio.
It will also allow you to compare which set of ratios work best for you. This is a modified version of one that I posted a few years back. Just fill in the yellow and green sections.
By the way, the 01E Audi 6 speed boxes - DQS, FRG & GAZ will give you the best top speeds.

Cheers

Bill.

 

[Ron Earp]

Or take a different approach, build a motor that can sustain and take more RPM as I and some others have done. 7500 RPM, even with a 5N the common short geared box, would give you about 190mph. Plently.

R

 

[Johan]

There's a factory tuned Ford 302 engine here i sweden that revs 9000, but the LS6 in the new corvette seems like a better alternative and that revs 6900 so /ubbthreads/images/graemlins/smile.gif I'll take a look at that calculator!

 

[Mike Dozier]

I assume there a rev limit on stock transaxles....bearing speed limit....poor synchro function... lubrication issues...something like that. How high can you run these
boxes in stock form?

MikeD

 

[Ron Earp]

There probably is a limit on paper, but if that means anything in real life is another matter. I'm sure Mazda didn't design their Miata transmission to be raced 24 hours at a time up to 8000 RPM, but it happens all over the country and seems to have zero issues. My own is a 204k original with no mods and over 39 race hours with nothing but oil changes. Shifts great!

Ditto all the other street cars racing in SCCA form which allows no modifications, coolers, bearing strengthing, etc.

On the other hand they don't deal with as much power and are not transaxles. Big difference there!

 

[Kristian Wraae]

@Cassius, sorry if this is slightly off topic.

I understand you are building a race car. Any plans on registering it for the road ?

The reason I ask is that I live in Denmark and no kitcars are (as far as I understood last time I talked to the authorities) allowed here (you have to provide a lot of safety information - calculated crash tests, emission etc).

I have seen a few kit cars on Sweedish plates. So would it be possible to register the GTD40 or the likes for the road in Sweeden ? Fingers itching to get one.......