Z06

MJSPEED,
Great info.

Has anybody noticed what the drop is between gears on a GT3,
I will not be driving my car until May,
New insurance mandatory minimum 2 months no driving coverage,

MetalSolid

On Rockit's graph power falls off very quickly after 7400 rpm. This isn't consistent with how it feels on the track/street, feels like the engine has immense power all the way to redline, more like or better than Porsche's graph.

Bob Rouleau

Interesting thread. FWIW, the 996 race cars all have much shorter gearing than the street versions. Of course they have no EPA issues nor if fuel economy a factor. Viken changed the gearing on his 993 and reported favorably. At my favorite track the GT3 is perfectly geared, it has more grunt out of the esses and bridge turn than my GT2 which is "in between gears" at the asme place. Needless to say 6th gear is useless but 5th is needed on the back straight. For Z06, I saw nearly 255 KPH at Mosport.

Regards,

bob_dallas

Looks to me like they stopped testing around 7400 on Rockit's graph - not surprising. I can guarantee that the power doesn't drop off like that!

Shifting at or very close to redline keeps you in the max powerband on this car.

Bob Rouleau

Bob - I agree, the car pulls hard til 8000. I like the fact that the broader power band means that for some tracks I don't have to shift to 4th and back to third. The extra revs compared to 6800 on my GT2 makes a difference. Still if I could wave a magic wand, I'd go for the shorter gears and have even more torque mutiplication. The Cup cars accelerate harder and while they are lighter most of them have shorter gears - as Z06 observed, I don't know of a track where I could get to anywhere near 190 MPH. The best I have seen is about 155 MPH. I know we can change individual cogs in the GT3 but I wonder if a higher numerical ring and pinion is available. We could do burnouts in 3rd gear

Z06

MetalSolid, All correct dyno charts will have torque and hp equal at 5250rpm, if you look at Rockitmans dyno they are equal at 5250, now how Porsche found that dyno is interesting.

I started a thread @ the Performance and modification da area on this forum with the previous posted info i found on a search and Bill Verburg had different #'s.
https://rennlist.com/forums/showthre...62#post1204562

Bob, That's a good mph, is that with the GT2? ..........I usually run at Shannoville and Cayuga.........I tend to like pushing it and Mosport is not so forgiving.

I think because of the computer cam adjustment it makes for a very wide power band, and i can see it not loosing allot of HP, for a few rpm after peak hp.

rockitman

That is correct Bob, they stopped the test at approx 7400. They felt the car had achieved max power at that point, so there was no point going to redline...Were they wrong??? Was there some power left on the table???

GrantG

Alain Prost's recommendation is applicable to the very close ratios in his formula cars. With the wider spacing of the GT3, shifting at or near redline is the way to go...

MJSpeed

Actually it's applicable to saloon cars as well, you want the engine to be at its optimum power and torque points so that it can constantly be giving you the max it's got to offer...either way try it and only "your lap time" will tell ...just my $.10

Bob Rouleau

Interesting observation about HP and Torque curves at 5250 RPM..makes sense since HP = torque x RPM/5250. At 5250 RPM, HP=Torque x5250/5250 or HP = Torque.

ZO6 the 255KPH was in the GT3 - The day I ran the GT2 it was raining. I agree with you view, Mosport is a very dangerous track and in the rain caution is advised.

Regards,

bob_dallas

I doubt seriously that power was left on the table - peak power at least. My point was that it's not an accurate depiction to guage shift points from because power doesn't drop off that abruptly at 7400.