What pressures are folks starting at front/rear when the tires are cold?

The car has or will soon have:

shortened/revalved Konis
27.5 mm torsions
375 # to 425 # rears
3/4" adjustable rear bar
targeted to weigh 2140 to 2150 with driver for end of race

tia,

tom

 

I'm assuming you're using the 215/50-13 or the 225/50-14?

Anywho...my car, 2300 pounds on 15x7's with 205's, likes about 26 psi cold. Since you're about 150 lbs less, on 6" wheels, with wider tires, I would imagine somewhere in the 26-30 psi range starting would be a good place to start, perhaps 27 front and 30 rear since the fronts will work harder and the pressures will grow more. If you can get somebody to get hot pressures for you, shoot for ~35 psi hot as a starting point.

 

should have included the tire size. i am on the 205/55R14's. The 6 inch rim is correct. With the 205's, there is very slight rubbing on the inside fender well.

may try the 225's but the tire place is already complaining about how difficult the 205's are to mount!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tom91ita &raquo;</TD></TR><TR><TD CLASS="quote">...tire place is already complaining about how difficult the 205's are to mount!</TD></TR></TABLE>

Let them try to mount 225/45/13 Hoosiers on a 6" rim and then see if they complain about 205's. I'd shoot for somewhere between 35-40psi hot, just don't get them above 40, that is the magic number, or so I've been told.

At BeaveRun in June (85-90 degrees both days w/ 100% humidity) I was starting the fronts at 30 and the rears between 34-36 and was finishing pretty close 40 all the way around.

Just my $.02.

 

BTW: My "shoot for 35 psi hot" comment was based on my pyrometer data, not just seat-of-the-pants, anything more than that and the center of the tire was hotter than the outside and inside. YMMV.