VW FINAL DRIVE

I am in the process of rebuilding my gearbox and was wondering what would be the best final drive ratio. It presently has a 3.6 and I see that a 3.9 or a 4.2 are available. I'm up here in the northeast (LRP, WGI). I would appreciate any help

jerry

Jerry,

The 4.20 (or 4.25) will probably work well at LRP, but it may be too short for WGI. You may run out of gear on the back stretch. The 3.89 or 3.94 should be fine there. I don't have any experience for NHIS, so I can't comment on that.

BTW, a 4.25 is about perfect for Summit Point, but it's too short for Pocono if they run NASCAR Turn 1.

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MARRS #25 ITB Rabbit GTI

Jerry, I have lots of experience at Lime Rock with the ITB Scirocco, and ran both WGI courses, with an excellent (0.2 off the record) time on the short course. Assuming 14" wheels, the best combo seems to be the STOCK 9A ratios (1.44 3rd, 1.13 4th) with a stock 3.67 final drive. With that totally stock box (mine just has an added Quaife), both tracks just use 3rd and 4th (as long as they use the chicane at the Glen), and there's still 2nd for making a good start or 5th for drafting that Volvo or ITS car http://Forums.ImprovedTouring.com/it/wink.gif The 3.94 (stock 2H or 4K box) seemed to hurt at Lime Rock, as a shift to 5th was necessary halfway down the straight and the back section didn't work quite as well. I can't imagine that it would be any better at the Glen.

Don't know if you're going to run NHIS. the 3.67 works better there as well than the 3.94. A 4.4 ratio worked even better than those, but it was a disaster at Lime Rock. Never got a chance to try it at the Glen.

9A and 3.9 with 13" tires .welded. fastest anywhere with legal cam. You should have to shift at LR and at the top of the hill at WGI. A 3.67 will allow to carry 3rd between 8and9 at WGI but slow up the hill at the toe.
4.22 car has NG cam at Summit. Maybe 16V??MM