View Poll Results: What are your hot tire pressures with the MPSC2?
Front: 30 or 31
30
46.88%
Front: 32 or 33
22
34.38%
Front: 33 or 34
7
10.94%
Front: 35 or 36
5
7.81%
Rear: 30 or 31
10
15.63%
Rear: 32 or 33
14
21.88%
Rear: 33 or 34
14
21.88%
Rear: 35 or 36
18
28.13%
Multiple Choice Poll. Voters: 64. You may not vote on this poll
Hot Tire Pressures on Track with MPSC2
03-16-2015, 10:48 PM
#16
Could be your camber settings? You're potentially not using the full width of the tire at higher pressures? Do you have a pryometer? Measuring outside, center and inside temps at different pressures will help dial this in. Pressure is often does as a quick fix because it's the easiest to do at the track, but it really should be done last.
03-17-2015, 04:13 AM
#17
Rennlist Member
I experimented a bit with pressures and it appears for track 29F & 31R hot is best combo. For Autocross I run 30F & 32 R hot. This car & tire does not favor higher pressures. Mark
03-17-2015, 07:32 AM
#18
03-17-2015, 10:06 AM
#19
I initially put front on loose and rear on firm but the car was unsteady at corner entry but it did great. Once I put Trofeo-Rs on, the car handled differently and I had to dial the rears in a bit so now I have the rear in mid position. I think the front needs to stay loose to reduce the car's tendency to understeer and the rears either mid (stock) or firm positions, depending on your driving style.
03-17-2015, 10:38 AM
#20
Rennlist Member
BTW: Here is my set up
Front : ARB #2 " middle"
Camber -2.3"
Caster Factory
Toe 0.5 mm out
Rear: ARB #1 " stiff"
Camber -2.0"
Caster Factory
Toe 2 mm in.
with 30 psi all around, the car is almost perfect on OE tires, and very predictable.
03-17-2015, 12:17 PM
#21
I initially put front on loose and rear on firm but the car was unsteady at corner entry but it did great. Once I put Trofeo-Rs on, the car handled differently and I had to dial the rears in a bit so now I have the rear in mid position. I think the front needs to stay loose to reduce the car's tendency to understeer and the rears either mid (stock) or firm positions, depending on your driving style.
Cool, thanks for that. Do I need to jack up the car?
03-17-2015, 06:56 PM
#22
Rennlist Member
yes, you should have someone do it for the 1st time while you observe, there is always somebody with tools and skills in the garages if you go looking
03-17-2015, 09:33 PM
#23
03-18-2015, 06:58 PM
#24
Rennlist Member
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With -2.0 cambers and alignment otherwise at factory settings, and factory sway bar settings, 30 F and R seems pretty good, based on looking at the tire wear. But this is on a track (VIR) which doesn't have many long corners with high lateral G, so the track is fairly easy on tires. There's a bit of understeer, but I need to track the car more and maybe get some tire temps before I consider changing anything but the hot pressures.
Overall, I'm impressed with the tires so far. Grip is good enough and not overly sensitive to pressure - I rode with a superb driver in his 991 GT3 with the same tires, and he showed me how fast the car is even with pressures in the high 30s! And the tires deliver this performance while being quiet and comfortable on the road ...
Overall, I'm impressed with the tires so far. Grip is good enough and not overly sensitive to pressure - I rode with a superb driver in his 991 GT3 with the same tires, and he showed me how fast the car is even with pressures in the high 30s! And the tires deliver this performance while being quiet and comfortable on the road ...
