Increasing Negative Cambers
10-16-2017, 06:05 PM
#47
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Thanks TRAKCAR. My 991 GT3 is the first 911 I have had that wasn’t a 70s. I am having difficulty getting used to the low speed understeer. It is so different in that regard from my GTU 911, based on a 1972 coupe. I take it that I will have to deal with it by staying as far out in the low speed turns as I possibly can. I have tried weight jacking. Of course the penalty for this is pronounced understeer the other way!
i appreciate you tuning in. I will leave my camber alone for now.
i appreciate you tuning in. I will leave my camber alone for now.
10-16-2017, 10:59 PM
#48
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My 991 GT3 is the first 911 I have had that wasn’t a 70s. I am having difficulty getting used to the low speed understeer. It is so different in that regard from my GTU 911, based on a 1972 coupe. I take it that I will have to deal with it by staying as far out in the low speed turns as I possibly can.
10-17-2017, 11:22 AM
#49
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Manifold, thanks for that. I have been working on my trail braking timing. After 25 yrs, no track driving, I get it right about 1 out of 3 or 4 times! What seemed to work best on the old 911 GTU was about 2psi lower in the front. Last time at the track, I was trying that, but with about 1psi lowerthan LF in RF. The track is AMP in Georgia and it is primarily ccw. So this setup helped with the small LH carousel (about 40 something mph) on which I stayed as far out as I dared, with the fence really close. But it was a mess on the RH hairpin—serious understeer, as you would expect. I realize the MPSC2’s are different from the racing slicks of the 70s and 80s— I ran much lower pressures, then. But if I get down as far as 30 on the MPSC2’s, the temp is lower in the center. About 32 in front the temps are pretty even. With 32f and 35r, am I in the ballpark?
10-17-2017, 08:33 PM
#50
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Manifold, thanks for that. I have been working on my trail braking timing. After 25 yrs, no track driving, I get it right about 1 out of 3 or 4 times! What seemed to work best on the old 911 GTU was about 2psi lower in the front. Last time at the track, I was trying that, but with about 1psi lowerthan LF in RF. The track is AMP in Georgia and it is primarily ccw. So this setup helped with the small LH carousel (about 40 something mph) on which I stayed as far out as I dared, with the fence really close. But it was a mess on the RH hairpin—serious understeer, as you would expect. I realize the MPSC2’s are different from the racing slicks of the 70s and 80s— I ran much lower pressures, then. But if I get down as far as 30 on the MPSC2’s, the temp is lower in the center. About 32 in front the temps are pretty even. With 32f and 35r, am I in the ballpark?
10-17-2017, 09:06 PM
#51
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Thanks, guys, for your help! I’m going to start with 32F and 34R, leaving the camber at 2.36F and 2.52R. I’m due a new set of MPSC2’s, which I will probably have put on at the track Thursday. I’m still running lateral acceleration of 1.35G, but I’ve backed off a bunch because I’m running out of rubber on the fronts. With fresh tires, I run around 1.55G on a good day. There may be more, but I’m sneaking up on it! :-)
stay safe!
Dave
stay safe!
Dave