dirtdoc

I just had TRG replace the R&P, LSD, LWFW... and from my first driving impressions it was certainly worth the price of admission. Acceleration is noticably improved throughout, although first gear is somewhat useless as it is really short and will spin the tires without carefull throttle application. It took a little adjustment getting used to the new shift points (speed vs. rpm) but anticipate a nice decline in lap times. Can't wait to get it on the track.

A big thanks to Austin and the folks at TRG. See you out at SP on the weekend.

RS Patrik

Well,
not exactly. I changed the final drive to 8:32. This means all gears are lower. Don't know the effect on the top speed, I stopped at 295km/h and it was stilling pulling hard.

This procedure was the best mod ever. The car is so much better than before, just wish this was available from the factory.

Highly recommended.

NelsonF

While changing final drive or r&p does improve response, it still does not improve the signifcant gap felt from 2nd to 3rd and 3rd to 4th. So I would advocate changing to closer ratio gears (3,4,5 and moving the orginal 5th to 6th) for more optimized spacing. Above 4th, the car will be north of 120mph and the impact of spacing is less problematic on most tracks.

NJ-GT

I agree that changing gears is a better choice.

However, I think the 3rd to 4th ratio is good. The 3rd to 4th upshift lands at 6,400 rpm. Below 6,400 rpm, these cars don't produce as much power. The sweet spot for the 996 GT3 is between 6,400 rpm and 8,200 rpm. A 1,800 rpm gap between 3rd and 4th is very close IMHO, and it matches the powerband.

Look at the power curve in my dyno graph below. In my specific application, the lowest gear I use at any of my local tracks is 3rd, so my car works pretty well. I also run autocrosses, so the shorter 2nd gear is a benefit.

However, if the car is not going to be used for autocross, new 3rd, 4th and 5th, and replacing 5th into 6th is a better choice.

NelsonF

Does anyone know if they've adjusted the gear ratio's in the 997 GT3's to address the situation? I hear that they have closer ratios but given the larger tires they are running it might be a wash. It will be interesting how close ratio 996 cars compare with the new ones one the track. My sense is that it will be close.

NJ-GT

They've adjusted the ratios, but the ugly gaps between 1st, 2nd and 3rd are still there.

996 GT3 / 996 GT3 RS: Ring & Pinion Gear: 3.44:1 (295/30R18 25.0")
===================================================
Gear Ratio---Gear --- RPM drop on upshift --- Max Speed at 8,200 rpm (8,000 in 5th and 6th)
===================================================
3.82------------1st---------------------------------46 mph
2.15 -----------2nd ----------4600 rpm----------82 mph
1.56 -----------3rd-----------5950 rpm----------114 mph
1.21 -----------4th-----------6350 rpm----------147 mph
1.00 -----------5th-----------6800 rpm----------173 mph
0.85 ---------- 6th ----------6800 rpm----------203 mph (8,000 rpm)

997 GT3 / 997 GT3 RS: Ring & Pinion Gear: 3.44:1 (305/30R19 26.3")
===================================================
Gear Ratio---Gear --- RPM drop on upshift --- Max Speed at 8,400 rpm (8,000 in 5th and 6th)
===================================================
3.82------------1st---------------------------------50 mph
2.26 -----------2nd ----------4950 rpm----------85 mph
1.64 -----------3rd-----------6100 rpm----------116 mph
1.29 -----------4th-----------6600 rpm----------148 mph
1.06 -----------5th-----------6900 rpm----------172 mph
0.92 ---------- 6th ----------6950 rpm----------198 mph