Civic44

Hello,

I recently purchased a 2002 Civic hatch with a K24 swap to serve as my track car. I installed Dynamics coilovers (from the Canadian Honda Michelin Challenge series) and that's basically it suspension-wise. I have 3 degrees of negative camber in front, 1 at the back, 1/16 toe out in front, close to 0 in back. The car has no weight reduction, so weighs about 2740 pounds without driver.

I bought RE71R's in 205-50-15 because I am running the oem 15x6 wheels and did not want to invest in wider wheels yet.

My first track outing was a few days ago at a small local track (St-Eustache) which I know very well. I started out at 32 psi all around. I did a 25-minute session and forgot to check the pressures immediately, but even after a few minutes, the fronts were at 47 and 45 psi.

I had another session the next day, and dropped the front cold pressures to 26 and 28 (26 for the tire that sees more turns) and remembered to take the hot pressures after the session. They were 45 and 42 psi. This seems high to me. The car seemed to have a bit more front end grip, but did not meet my expectations from these tires.

I am writing to figure out my next move. Do I need to use a laser thermometer (I have one, never used it yet) to evaluate? If so, what ideal temps am I looking for. Should I use chalk on the sidewall? Thanks in advance for any advice.

ericroan

you should be hitting around the yellow line when running hot.
if not, then adjust the tire pressure accordingly.

Civic44

OK, thanks, I will try that with white marker

Civic44

I think I pretty much hit the mark. This was at Calabogie, started with 28 psi cold in front on both sides, it rose to 43 left, 38 right, but felt good. Sadly, I only got one dry session so not a ton of track time, but the grip was really good. I can barely feel that I don't have an lsd on the car.

ericroan

I ran around 25-30psi hot on my eg, 205-50-15 on 15x8

Civic44

Does that mean you start at like 18-20 psi cold?

ericroan

Yeah, I start at around 20 in front, rear around 24 then adjust from there.
RE71R is almost like R comp and it worked well for me running around 25-30psi hot
but doesn't mean it will work for you, so just play with it and figure out what works for you.

FormulaIntegra

Tread temperatures have always been my best indicator for correct pressure. The laser thermometer is a great tool. A tire temperature probe will be even more accurate.

Measure 3 points across the tread (inside, middle, and outside). You're looking for an even balance across. Much hotter on the inside, and your pressures are too high; outside too hot, and they're too low. Adjust the pressures in small increments to see how much it affects the temp spread. Sometimes all it takes is a 1/2 psi to dial them in.

Every car, track, and tire are different, so the cross-tread temperature is your best indicator wherever and whatever you race. Driving style will also affect tread temperature, as well. Also, check with the tire manufacturer's specs for ideal temperature and camber angles.

Civic44

I will try a laser thermometer, since I already have one (still new in the packaging). I just have to take the time to measure stuff and write it down, as I am usually instructing to get free track time, and running to a student's car instead of gathering useful data for myself. Anyway, even if I am not at the ideal pressure yet, there is no championship on the line and the tires are wearing evenly, so I will do what I can when I can. Depending on how many students I have at my next HPDE on Monday, I may have time to gather more data and post it here.