I am running 205/50/15 on 15x7 wheels. I run track days, but don't know what pressure to run. Some people tell me as low as 32, some as high as 40. So far 40 cold is what i run, but feels like crap. And the air pressure, should that be checked cold or hot? Road racing 94 civic coupe. Tires 615 azenis.


Modified by Tarmac Junkie at 4:19 PM 9/30/2006

 

I assume that when you say "track days", you're talking about a real racetrack, i.e. not a dragstrip.

40 cold is probably too high.

The best pressure depends on what kind of tires you have, and a bunch of other things. I'll give you a few examples.

On my Integras (Type R and GS-R), the stock pressures recommended by Acura in the car's owner's manual (35F/33R), measured cold, seem to work well for street tires used on the track. Keep in mind, though, that both of these cars are designed to be sporty cars, with performance in mind.

I have heard that base model Integras recommend pressures 6 psi less than the ITR and GS-R, ostensibly because those models place more emphasis on ride comfort than on performance, so even those models might be best at the higher pressures recommended for the ITR and GS-R.

With R compound track tires, the tire manufacturer often recommends a particular pressure, measured hot. For example, Toyo recommends 38-42 psi, measured hot, for their RA-1 track tire. For track use, I generally set my RA-1 tires around 31-32 psi cold all around, and it seems to work well. I don't bother measuring them when they heat up, but they're probably getting to Toyo's recommended 38-42 range.

Yokohama A032R (R compound track tires) seem to like lower pressures, and I was setting those around 28 psi cold all around.

As usual with tire pressures, these are starting pressures. If you don't like the results you get, you can play around with them and adjust them until you think you're getting the best results. You can use a pyrometer to measure temperatures; the optimal pressures will give uniform temperatures across the tread. You can also ask anyone who's using the same tires as you are, preferably with the same car, too, to see what they're using and how they like them.

In the absence of any more specific information, I think setting tires in the low thirties, measured cold, will probably give decent results, and then you can adjust from there.

 

Any other thoughts??