Tire pressure.
05-26-2015, 12:10 PM
#1
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Tire pressure.
Fellas,
What tire pressures are you guys running at the road course track? What's your set up?
What tire pressures are you guys running at the road course track? What's your set up?
05-27-2015, 08:09 AM
#2
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2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
38F 37R is what the Longacre Pyrometer told me
Running Michelin PSS 245/35/19F and 275/30/19R
Running Michelin PSS 245/35/19F and 275/30/19R
05-27-2015, 06:27 PM
#3
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W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, C5 Z06 & IS300 race cars, EQE 4Matic+ on order
On the C63 coupe - my street car - I found that the R888s really come into their own at higher pressures that any other R-comp I've ever used on my P-cars of comparable weight (RA1s liked about 40 psi hot, Michelin PSC and Hoosier R6s another 2-3 psi lower that that). At ~38 psi hot the R888s felt quite loose and I ended up scalloping the fronts. On a suggestion from someone else running R888s on a 997 TT, I upped the pressures to about 40 psi cold (which resulted in about 48F / 46R hot) and they felt a tad more sliuppery than the RA1s but definitley a huge improvement over how they felt earlier. Let out about 3 psi on all four corners and was then running 44-45F / 42-43R hot (pressure indicated by the on-board TPMS during the actual run - not after the coold-down lap), which I found to be the sweet spot and they hooked up at least as good as the RA1s on my Porsche.
As a general rule, suggested pressure for Toyo R-comps on a track-driven street car is 40-43psi hot. Toyo has also indicated that he R888s like higher pressures and lower camber than the RA-1s (they sponsor CASC-OR so one of their guys is usually there at most events), so this also seems to be in line with what he said. The sidewalls are quite stiff so you don't need to worry about rolling them over (like the Michelin PSCs) with street camber.
Good luck - and let me know what you find out. If they seem too loose or squirmy, up the pressurees to 40 psi cold, see how they feel (they'll go up by 6-8 psi hot) and then you can fine-tune it from there.
As a general rule, suggested pressure for Toyo R-comps on a track-driven street car is 40-43psi hot. Toyo has also indicated that he R888s like higher pressures and lower camber than the RA-1s (they sponsor CASC-OR so one of their guys is usually there at most events), so this also seems to be in line with what he said. The sidewalls are quite stiff so you don't need to worry about rolling them over (like the Michelin PSCs) with street camber.
Good luck - and let me know what you find out. If they seem too loose or squirmy, up the pressurees to 40 psi cold, see how they feel (they'll go up by 6-8 psi hot) and then you can fine-tune it from there.
05-27-2015, 07:13 PM
#4
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It does vary between what track you're running at as well. Some left handers or right hander friendly tracks will vary what pressures you run for each tire. Even type of tires vary as well. Nitto NT05's I typically just run around 35-38psi hot.
-Luccia
-Luccia
10-01-2019, 12:12 PM
#6
Bumping this back up. Did an event yesterday and was playing with pressures. I run Michelin PSS. I was playing with 41-44 hot and was happy with how the car felt. I ran out of time and didnt get to try lower.
Anyone have experience with 37,38,39 psi on a streetable summer tire?
al
Anyone have experience with 37,38,39 psi on a streetable summer tire?
al
10-01-2019, 12:50 PM
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10-01-2019, 01:16 PM
#8
10-01-2019, 03:44 PM
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I think the sweet spot is probably right around 40 cold for PSS/PS4. A psi or two either way is just rounding.
10-01-2019, 04:48 PM
#10
10-01-2019, 06:59 PM
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Sorry you’re right. I was thinking about the higher pressure I run the PSC2’s at.
Also my first post above was referring to cold spring temps at WGI. In the summer you’re going to want to run higher pressures probably.
Also my first post above was referring to cold spring temps at WGI. In the summer you’re going to want to run higher pressures probably.
