On track experiences and video's 991 GT3 only.
#106
Rennlist Member
Thanks sam + Dan - always good to compare notes. We are learning this together.
3.0/2.5 is fairly aggressive. Its the max Geo I run for my 993 on the track. I like that set up but it does wear tyres faster on the road. My 993 has cost as much as my 991 GT3 over the last 4 years to make quick on road and track and I promised myself apart from SW bypass (yes I forgot to say I have that on my car in the video) I did not want to go crazy after market with the suspension. That being said spacers are low cost option to get those settings as Sam did. Personally I feel the ideal aggressive but all round acceptable setting for this car would be -2.5 front and -2.0 rear with rear sway bar set middle hole (neutral as per factory) and front bar softened off one notch. However I have yet to try that set up myself.
YOCOHO my car is ROW Clubsport spec (carbon buckets, half cage, fire extinguisher and 6 point harness as standard).
I have been told that the car is fine on any R comp tyre but not a 100% slick one. I think this is simply caution from PAG. You could run a R6 if thats R comp dot rated. Personally myself I will run any tire I believe will give the best grip regardless of type on this car. Guys have been doing taht on CL 997.2 GT3 for years no problem and I dont anticipate any issues here...
3.0/2.5 is fairly aggressive. Its the max Geo I run for my 993 on the track. I like that set up but it does wear tyres faster on the road. My 993 has cost as much as my 991 GT3 over the last 4 years to make quick on road and track and I promised myself apart from SW bypass (yes I forgot to say I have that on my car in the video) I did not want to go crazy after market with the suspension. That being said spacers are low cost option to get those settings as Sam did. Personally I feel the ideal aggressive but all round acceptable setting for this car would be -2.5 front and -2.0 rear with rear sway bar set middle hole (neutral as per factory) and front bar softened off one notch. However I have yet to try that set up myself.
YOCOHO my car is ROW Clubsport spec (carbon buckets, half cage, fire extinguisher and 6 point harness as standard).
I have been told that the car is fine on any R comp tyre but not a 100% slick one. I think this is simply caution from PAG. You could run a R6 if thats R comp dot rated. Personally myself I will run any tire I believe will give the best grip regardless of type on this car. Guys have been doing taht on CL 997.2 GT3 for years no problem and I dont anticipate any issues here...
#107
Yes, it is a work in progress and I love to compare notes. Here is a picture of my left front (it did more clockwise than counterclockwise). I think it is wearing evenly, except for the second row from outside, which seems to be taking a lot of wear. Total miles on this tire: about 1,400. Total track miles: about 180. I think well balanced wear, no?
#108
Rennlist Member
Yes, it is a work in progress and I love to compare notes. Here is a picture of my left front (it did more clockwise than counterclockwise). I think it is wearing evenly, except for the second row from outside, which seems to be taking a lot of wear. Total miles on this tire: about 1,400. Total track miles: about 180. I think well balanced wear, no?
#109
Rennlist Member
Mark. You are on the right track here. I would start 25/29 at ambient 20C (not sure on F). You will be 32/36 after 6 laps I should think. It will increase to 37/39 before you finish the session but the chassis pulls it all together no problem. After that Id say youll only need to drop 1-2 psi front and rear over subsequent sessions. Just make sure you put air in them on the way home. Understeer increases a little as the front tyres get above 35 and start scrubbing wide a little. But its very neutral in comparison to an older 911 and the car is never a handful at these tire temps.
#110
Rennlist Member
Mark. You are on the right track here. I would start 25/29 at ambient 20C (not sure on F). You will be 32/36 after 6 laps I should think. It will increase to 37/39 before you finish the session but the chassis pulls it all together no problem. After that Id say youll only need to drop 1-2 psi front and rear over subsequent sessions. Just make sure you put air in them on the way home. Understeer increases a little as the front tyres get above 35 and start scrubbing wide a little. But its very neutral in comparison to an older 911 and the car is never a handful at these tire temps.
#111
Sam, the wear appears to be fairly uniform across the tire. It looks great. What cold pressure did you start with and what hot pressures did you maintain or shoot for. I had a quick run today just to get a quick baseline. My camber is stock and is roughly -1.5 deg front & back. I started at cold pressures 26F/30R and ended up at 31F/36R hot pressure after 4 laps. Outside temp was 78F. The car felt really good and with great traction and very minimal understeer. It could use however slightly aggressive camber which I am planning to change the Front to -2 deg as Macca suggested. Next Sunday will be much hotter so I am thinking about starting with 1 to 2 psi less cold pressure all around. The car feels really good and well balanced when tire pressures below 35 psi. Today was just getting a little feel for the car stock and without any adjustments. I just wanted to establish a baseline. Mark
As you can see in my track video, I am driving the car very hard. Regardless of ambient temperatures, I always gain 9-10 PSI. I usually get tires to temp (feel it in grip) after one lap in the summer and 2-3 laps in the winter. Macca's advise to start just a few PSI below and bleed later is sound. I am too impatient so I start lower. I try to be at the rack early enough so the tires cool down, then I bleed to a rediculously low 18 F and 19R. if the stars align, I am at 28 F and 29 R by the end of the session, which I found work best for my style of driving and car setting.
Sam
#112
Mark,
As you can see in my track video, I am driving the car very hard. Regardless of ambient temperatures, I always gain 9-10 PSI. I usually get tires to temp (feel it in grip) after one lap in the summer and 2-3 laps in the winter. Macca's advise to start just a few PSI below and bleed later is sound. I am too impatient so I start lower. I try to be at the rack early enough so the tires cool down, then I bleed to a rediculously low 18 F and 19R. if the stars align, I am at 28 F and 29 R by the end of the session, which I found work best for my style of driving and car setting.
Sam
As you can see in my track video, I am driving the car very hard. Regardless of ambient temperatures, I always gain 9-10 PSI. I usually get tires to temp (feel it in grip) after one lap in the summer and 2-3 laps in the winter. Macca's advise to start just a few PSI below and bleed later is sound. I am too impatient so I start lower. I try to be at the rack early enough so the tires cool down, then I bleed to a rediculously low 18 F and 19R. if the stars align, I am at 28 F and 29 R by the end of the session, which I found work best for my style of driving and car setting.
Sam
#114
#115
The Michelin slicks for Cup cars? I've seen people running them on Turbos and so on, but they're 2.5x as expensive as the MPSCs...
#116
Last time I emailed Hoosier, about 6 or months ago, they told me they had no plans of making 20's. I suspect they wear out rather quickly if they fit.
#118
Rennlist Member
Mike yes I have some from the same albeit 3-4s slower! I'll try and get one up tommorow. The 993 Vmax is 200 on the straight compared to 231 gps verified. Traffic is a problem in the 993 but not the GT3. The 993 is almost as quick in the tight stuff but heavily modified car beyond RS spec and driven closer to the limit whereas the GT3 laps were first time on track and exploratory. 1.12 should be achievable in the GT3 without any further changes and by comparo that's the time the 996.2 GT3 cup cars do at that track in qualifying...
#120
Rennlist Member
Mark,
As you can see in my track video, I am driving the car very hard. Regardless of ambient temperatures, I always gain 9-10 PSI. I usually get tires to temp (feel it in grip) after one lap in the summer and 2-3 laps in the winter. Macca's advise to start just a few PSI below and bleed later is sound. I am too impatient so I start lower. I try to be at the rack early enough so the tires cool down, then I bleed to a rediculously low 18 F and 19R. if the stars align, I am at 28 F and 29 R by the end of the session, which I found work best for my style of driving and car setting.
Sam
As you can see in my track video, I am driving the car very hard. Regardless of ambient temperatures, I always gain 9-10 PSI. I usually get tires to temp (feel it in grip) after one lap in the summer and 2-3 laps in the winter. Macca's advise to start just a few PSI below and bleed later is sound. I am too impatient so I start lower. I try to be at the rack early enough so the tires cool down, then I bleed to a rediculously low 18 F and 19R. if the stars align, I am at 28 F and 29 R by the end of the session, which I found work best for my style of driving and car setting.
Sam
One final comment regarding front to rear pressure differential. You are only 1 psi between front to rear. I wonder how is the car balance is affected. With 3 to 4 psi differential between F/R and factory stock sway bar setting, I found the car to be very well balanced with very little understeer or oversteer. Just wondering if you noticed any change to the car neutral balance with 1 psi differential, unless you have made other corrections such adjusting the setting in the sway bars or aggressive camber changes. Just curious. Thanks again. Mark