I have been told the best way to make your 964 quicker is to do just that. Change the gearing, and you won't worry about blowing the motor. After all Porsche has done just that to the latest 996 GT-3. Porsche reports a top speed of only 150mph for the 2004 GT-3 while a regular 996 C-2 has a top speed of 189mph. The GT-3 does 0-60 in 4.2 sec while a stock 996 does 0-60 in 5.0 seconds. The Gt-3 is lighter and has 60 more horsepower but it also gets better acceleration from a tighter gear ratio.

 

Sorry ,
Correction: the 996 has a top speed of 174mph.

 

Not a RS box but may be worth considering for a C2. No affiliation yada yada

http://mall.rennlist.com/scripts/fea...uery=retrieval

 

I too can vouch on the difference upgrading gears! it is night and day really... The euro G50/21 seems to be the best geared box, but they are hard to find and not cheap. Looking at the US 6 speed it looks like its the cheapest upgrade to improve 3-4-5 upshifts in relation to a US 5 speed on a 964. Comparing the ratios of the G50/20 to G50/21 it looks like the effect of improvement that i felt on my 993 with the shorter gearing should be felt with the US 6 speed on the US 964. There are a lot of people also that complain about the 6th gear been long on the US box... well 1st of all you will never ever use it on the track anyway ( even the short box) so it does not matter. When you need it is on the highway and having two identical cars with two different boxes I can tell you that if I ever shorten the gears on my cabrio which now has a stock G50/20 I would leave 6th alone! Driving my race car to the track at cruising speeds of 70-80mph 6th now is above 3000rpm with the equivalant noise so to speak. Compare that with about 2400 rpm on these speeds on the cabrio and it makes for a "relaxing' and quiet cruise so to speak. If I want to pass in a hurry a downshift or two is not that bad... So to be honest prices of the US G50 6 speeds are not that bad at all to make it a very expensive experiment so to speak... If you factor resale of your 5 speed especially...
I will not go into a selfless promo now, but I can tell you that I was asking around 2K for my G50/20 when I had it for sale at the Rennlist classifieds a few months ago.

 

FWIW, I ordered a '90 complete tranny w/ LSD, 40% locking factor, w/ appx 50K on it and it has quicker ring/pinion ratio. I stopped by Techs this PM hoping it was in...NOT, and Sebring's about 2.5 weeks away Says not to worry. Soooo.... when I get back I'll post on just how it does.
Oh, while the engines out the RS flywheel/clutch also goes in
Bill

 

No affiliation whatsoever, but I noticed this g50 for sale on ebay:G50 porsche 911 transaxle, race prepared