Performance improvements

[Guest]

While many of us have talked about lowering; reducing weight; turbocharging; supercharging; better suspension, etc.etc., but no one has mentioned different gear ratios. Is this a viable alternative to improve 0-60 and 1/4 mile performance as well as top speed? :rolleyes: :eek:

[umn]

Hi Don,

I hate to break the news to you, but you can't change the gear ratios in your box. This is because the gears for first and second are fixed to the input shaft and the gears for third to sixth are fixed to the output shaft, i.e. can not be removed. Also, neither Porsche nor GETRAG (who make the box) sell you any spares. NB: this is not true for the G50-derived boxes in the GT2/3 and TTs.

Even if you could change the gears, I don't think you would be able to improve 0-60 or top speed. As 0-60mph (or 0-100km/h) is such a common measure in consumer magazines, most sports car gearboxes are designed with that in mind. If you look at the G96/00 gearbox diagramm, you'll see that you hit 100km/h close to the end of second gear (about 6500 rpm), which is what you want. And you reach top speed at 7000 rpm, which is where the engine has its maximum power output and again that is exactly what you want.

It might be possible to improve quarter mile performance with a shorter box, I don't know.

Cheers,

Uwe

Edited February 12, 2004 by umn

[Guest]

Oh....Thanks for the lesson! :)

[umn]

Oh....Thanks for the lesson!  :)

Didn't want to lecture ... :oops:

[JimB]

Actually I've heard that there are a few places doing work on the 996 transmission. Apparently many of the gears and syncros are the same as the G50 or other older boxes and a couple of shops have popped up that will cut off the welded pieces and replace them. The shop where I have my racecar worked on recently had the input shaft rebuilt for a guy. Hopefully this will become more common or better yet Porsche will wise up and start building a serviceable tranny. The engine replacement program makes perfect sense to me but the transmission program sucks.

As for whether or not it should be done, at least for track use a higher first, a lower sixth and tighter ratios in-between would be fantastic. I don't think it would be of much value on the street though.

Jim

[dj996]

You can change the ring and pinion in a 996, I have seen the parts advertised. However, the tranny itself can't be serviced,how stupid is that??

That is very good news Jim, what shops are doing it?