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On track experiences and video's 991 GT3 only.

 
Old 07-22-2014, 07:55 PM
  #106  
Macca
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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...
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Old 07-23-2014, 12:10 AM
  #107  
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Originally Posted by Macca View Post
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.
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?
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Old 07-23-2014, 05:40 AM
  #108  
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Originally Posted by SamFromTX View Post
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?
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
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Old 07-23-2014, 05:46 AM
  #109  
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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.
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Old 07-23-2014, 06:02 AM
  #110  
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Originally Posted by Macca View Post
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.
Thanks Macca...I will certainly do so and report back. This car feels so good out of the box. I was blown away with its neutral attitude and specially how little understeer it has which gave me so much confidence to carry more speed into the corners that I ended up going in too hot on couple of occasions, then had to readjust my lines. It took a little while to get used to this amazing feel. Said that I completely agree that we should make only small changes at a time to learn how it effects the car and hopefully learn from one another comparing notes. I too and like you am planning to use the car for street driving as well as track and I really don't want to make drastic changes that can effect tire wear and feel on the street. Boy am I glad I stuck around and did not opt out. I love this car. Mark
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Old 07-23-2014, 12:05 PM
  #111  
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Originally Posted by mqandil View Post
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
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
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Old 07-23-2014, 02:44 PM
  #112  
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Originally Posted by SamFromTX View Post
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
Sam what tires are you running on your car?
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Old 07-23-2014, 02:51 PM
  #113  
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Originally Posted by YOCOHO View Post
Sam what tires are you running on your car?
Stock Michelin PSC2
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Old 07-23-2014, 04:26 PM
  #114  
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Originally Posted by SamFromTX View Post
Stock Michelin PSC2
I was thinking about running a set of Hoosier's just not sure if we can on the 991? Have you heard anything about running on the track Cup's or Hoosier's?
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Old 07-23-2014, 04:40 PM
  #115  
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Originally Posted by YOCOHO View Post
I was thinking about running a set of Hoosier's just not sure if we can on the 991? Have you heard anything about running on the track Cup's or Hoosier's?
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...
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Old 07-23-2014, 04:44 PM
  #116  
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Originally Posted by YOCOHO View Post
I was thinking about running a set of Hoosier's just not sure if we can on the 991? Have you heard anything about running on the track Cup's or Hoosier's?
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.
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Old 07-24-2014, 03:15 AM
  #117  
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Macca any vids of u driving your 993 on track for comparison sake? Mike
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Old 07-24-2014, 03:53 AM
  #118  
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Originally Posted by 996FLT6 View Post
Macca any vids of u driving your 993 on track for comparison sake? Mike
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...
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Old 07-24-2014, 04:19 AM
  #119  
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Looking forward to your 993 video. Thanks. Mike.
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Old 07-24-2014, 06:26 AM
  #120  
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Originally Posted by SamFromTX View Post
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
Thanks Sam. Very useful info. We have a relatively short track in Portland, and very little straight away to be able to get the car to higher speeds except for a short spurt, so it takes at least couple of laps to gain 6 psi's even if you are going hard, but your point is well taken about starting much lower pressures as sometimes we don't have the leisure to be able to stop and adjust the pressures.

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
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