Inverting Audi Gearbox

I'm trying to find info on inverting a Audi gearbox and flipping the ring gear. I know this can be done on the Porsche box but I can't find where anyone has done this with the Audi. I want a more correct drive shaft angle and lower center of gravity than an upright gearbox. I'm even willing to deal with the shifter problems if I can get the crank height and drive shafts correct.

Thanks
 
good luck, not the same as the porsche, i looked at it for a while, did not look even remotely possible, and im pretty adventurous. If driveshaft angles are what you want, buy a g50, look around, they can be had for $1200-$2000 if you look long and hard enough, and they are way stronger (not that alot of audi's are breaking). The money you would spend on building the audi like you suggest, would be better spent. And if your particular car only supports the audi box, it will be alot easier to modify your frame, as opposed to flipping the box.
 

Neal

Lifetime Supporter
Not sure how inverting the gearbox would lower the center of gravity as the spool is fairly low in the standard position. Here is a picture looking at the bottom of the box...

Jul29_01_34.jpg
 
I'm wanting to lower the engine as it has the most mass getting it lower will make a bigger difference than the relative light gear box. The main thing I'm after is the motor low in the chassis and the drive shafts near parallel to the ground. With the gear box in the upright and normal location it raises the engine a good 4 inch’s from the original or if the engine is mounted in the correct place the drive shafts are at some crazy angle because of the high input shaft to output shaft offset. With the Audi box upside down I can mount my engine at 2.5 degrees and the drive shafts are near perfect and the crank is very close to the bottom. I of course wanted to use the cheaper gearbox and save some money for other things, if no one has done this conversion or knows of anyone that can, then I better start looking for a Porsche gearbox now.
 

Neal

Lifetime Supporter
Interesting idea Mark. I'm not aware of anyone doing this with an Audi. One thing to be careful of is oil pan clearance. My Milodon road race pan is level with the lower frame rail. It's comperable to most wet sump pans in height. Cheers.
 
Well I wanted to go with a dry-sump set up and use a late model Ford V-10. The crank is higher in the block than the old style Ford blocks so this would allow getting the engine in lower because of the crank center line it can almost have a flat pan now if the transaxle would corporate.
 

Fran Hall RCR

GT40s Sponsor
I think the torque output from the V10 engine may well be you eventual downfall with this transaxle regardless of transaxle orientation..
 
The Audi transaxle probably is marginal in the torque department, but the Ford only has about 300ft lbs. I was hoping to get the bugs worked out of the car and then maybe save up for a Porsche transaxle.
 
I belive Ultima use the Audi 'box inverted. I posted a picture of it on this formum some time ago, a search may dig it out.

Hope this helps.
 
I believe Ultima use the Porsche gearbox. G50 and variations and the 993 Getrag Porsche box.
Mark
The significant difference between inverting the Audi (and the Reanult) compared to the Porsche, is the ring gear needs flipping in the Audi and Renault. It does not need this doing in the Porsche, because the Porsche normally sits in front of the Porsche engine, whereas the Audi and Renault sit behind the Renault and Audi engines. For our application with the box behind the engine the Porsche is easy - you turn it upside down and back to front, so maintaining 5 forward gears. If you turn the renault or Audi upside down you get 5 reverse gears, hence the need to flip the ring and pinion, which will be a pain. I have heard of a Renault which was done a few years ago in UK, but from what I've heard it was definitely not easy.
 
Back
Top