JasonAndreas

Before you waste a few thousand ($8k'ish) regearing a GT3 you might want to try some performance simulation programs (Bosch Motorsports freely available Lapsim is one example) to compare a regular GT3 with a regeared GT3. The results are very similar to running the cars next to each other in real life.

38D

There are far fewer options to change the R&P in a porsche than there are for front engined cars with a "rear end"

NJ-GT

LapSim is really helpful with a data logger, but a simulation with a short final gear with similar results to the stock final gear is far from real. That will be truth if the torque curve was flat, but it's far from flat.

Below 4,000rpm this car is weak, above 6400rpm the car is pretty strong. I've been at the track with quite a few other GT3s and the difference on the straights is evident. The 996 GT3 Cup has different gears for a reason, and the 997 GT3 Cup got them even better.

At the track I expend most of the time in 3rd-5th gear. On the stock GT3 3rd-6th gears are very close to each other. At the same speeds on the stock r&p I would be running 2nd-4th, the spacing between 2nd and 3rd is not good.

Anyone that has installed a shorter R&P on any car will support this real life facts.

I've been playing with LapSim for almost a year, it's pretty helpful to simulate the effect of weight reduction on lap times. That's one of the support reasons I work on weight rather than power on my car.

JasonAndreas

So in this situation (mostly a street driven GT3 with a few DE's) you would recommend someone spend ~$8k for a regear that will see them at most a few feet in front or even behind (obviously depending on the speed, how quickly someone can shift, etc.) the exact the same car with stock gearing? The lapsim (it was the first program that came to mind) times won't be exact but they'll be closer to reality than the performance claims made by a lot of vendors and mechanics. If I was racing professionally where a few feet makes all the difference than I (agree and) would definitely regear for every track but otherwise...

Z06

In the end of all this teck talk I did the regearing of my GT3 and I am glad it was done.. the car is a joy to drive, it has alot of jump.. it's much quicker.. I go by my old 420 rwhp Z06 and keep even with my friends GT2.. so to me it's worth $8k Can..that includes the single mass flywheel and all parts, shipping, everything complete.

One thing I recomend is doing some homework on the proper gearing.. match the gearing to the tracks you run.. top gear hyway cruise rpm, top mph. rpm drop between gears, get a chassis dyno, check the cup car gearing.. also compare it to the ferrari CS and you will be suprised how wide the gearing is in the stock GT3.
there is a little bit of work to get it right.. but it's worth it.
If your serious about doing it send a pm and I will give you the specific's on max gains.