Originally Posted by Dirty25RS
Whats your local AutoX track like?
track length (time, distance)?
number of turns?
I'm a little surpised you can heat up the 285s quick enough given the cobalt's mass.
I was planning on running that width on my BSP STi, which i think is a little heavier than a cobalt.
First! IT FITS LIKE A CHAMP!!! About 1/4" clearance between the most inner part of the tire and the strut -- it rubs against the lining rubber a bit, but the 285s have always done that even with the 8.5" wide rims -- I've got 20mm of positive offset (better then the 15 I had before) --and I'm not rubbing against any metal (a little up front - a strup about 3" long, but I dented it in and it's no longer a problem).
Track lengths are SCCA norm -- but regionally about 1 mile to 1.25 miles -- +or- a bit. About 55-70 seconds in DSP trim. We mostly use Pikes Peak Raceway and Dick's Sporting Good Park parking lots -- very large, very flat, very wide open.
Surface is mature asphault (although we used to use a concrete parking lot at Denver International Airport -- about 1/2 mi X 1/2 mi and very sticky. The airport lot was as big as the Nationals, Pikes Peak Raceway has hosted SCCA regionals, and we hosted an SCCA National Tour Event in Aspen last year (airport, concrete).
The local Porche and Corvette clubs also run on the road-race course at Pikes Peak (shorter than the parking lot courses) and run at Mile High dragstrip course area.
Turns are based on SCCA rules -- 'unprepared' (stock) cars shouldn't exceed the state speed limit of 75 mph top speed, no turns should allow more than 45 mph top speed. You can look on the rmsolo.org website for the Rocky Mountain SCCA data and I think there are some examples of track layouts. Probably, on average - including slaloms, at least 15-20/course to keep it to less than 75.
How to heat Hoosiers:
#1, I use a co-driver to help heat the tires -- just like about everybody else -- he drives first (#65) and I drive 2nd (#165) so I get to run near the end of the runs to watch the competition.
#2, I can easily light the front tires up at start.
#3, After about 2 runs, I'm usually spraying the tires with cold water to keep them cool -- Hoosier A6s like to be between about 110 and 120 degrees temp.
#4, The tires come home melted...