In trial and error I generally start cold at 29-30 PSI. Over 30 and I see 38-40PSI after a run depending on the heat.
30 is a safe place to start and you can adjust from there.
I've done a search on the board and I've found some conflicting answers.
I'm going back to Harris Hill this weekend for a real HPDE, no parade laps. I currently have Azenis, 205/??/15 on a set of Rotas.
Some drivers have said to shoot for 36 psi before each run. Opinions on cold PSI to start the day? 33-34 PSI?
Also, I have a one of these bad boys for cooking and figure I'll bring it to the track:
If I take tire temps after runs, how do I interpret that? What are general tire temps or the point where they start getting "greasy"? What about rotor temps?
Chris
91 Miata (#3), Rattle Can Grey(previous owner), Greddy Turbo @7 PSI and Manifold (Only items remaining from the kit), TDR I/C, Godspeed Radiator, RM DP, 2.5 Enthuza Bipes, BEGI AFPR, ACT, Lightened Stock Flywheel, Yellow Konis, FCM on Stock Springs, HDM2S, MOMO Wheel, Ratsback Front CF Lip, Black Rota's on EcstaXS, Corrado Rotors & XP8's on Front w/ 1.8 rears.
http://austinmiata.com/
Wishlist: Megasquirt to run 12-13 PSI, White non-spray paint job, 8" 6UL's, RX7 LSD, Evans Waterless Coolant
In trial and error I generally start cold at 29-30 PSI. Over 30 and I see 38-40PSI after a run depending on the heat.
30 is a safe place to start and you can adjust from there.
I always ran my Miata at 28 or 30 all around cold starting pressures I think.
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An IR thermometer is going to be useless at the track, First, surface temps and carcass temps aren't going to be the same (you want a probe-type thermometer to measure carcass temps). Second, by the time you take a cool down lap and come off track, your tires will have colled down substantially.
Iain
"We don't stop playing because we grow old, we grow old because we stop playing." - George Bernard Shaw
Check the Azeni website. I know that Toyo has RA1 information on their website. Generally speaking, the hotter the ambient temperature, the lower 'cold' pressure to start. For example, 95* or greater temps will put my 'cold' pressure at 28-29* start. I am looking for 37-42* hot off the track. I will start around 30-31* if temps are lower than 95*. It is only an estimate I have come up with. Some of the more experienced spec/track guys may chime in with more information.
I run 27 psi cold with 14" wheels on my NA.