Next week I will be attending the first autox this season. I have a 08 997 c2 with 18" wheels, mounted with trip 8's , f 225 & r 315. I will mark the sides of the tires with chalk to see the roll over. But not sure what pressures to start with. I was thinking of 36 f & 41 r.

I ran a Boxster S in prior years with RA1's at 38 f & 41 r, depending of the time of year.

You experience would be appreciated.

Thanks,

Harvey in MD

 

this may not be the popular opinion, but I think the tire pressures you are starting with are too high. Those would probably be my target hot temps

 

I would start out with lower pressures by perhaps 5 lbs. or so. Determine if you are having understeer/oversteer issues and adjust pressures accordingly. Understeer= increase front tire pressure. You might want to go down a little on rears but not much.

 

Hi Harvey,

I hope it is the Chesapeake Regions autox you speek of. I'll be there with my new ride! Stop by and see me and we'll talk. I'll be there early (7am) setting up a great course.

Joe

 

Start with 31f 35r. Also the narrow 225 front with huge 315 rear will really make the front push/understear and will be hard to get the car to rotate. Have fun though and keep the tires hot at around 38 all around.

 

Yea, does sound a bit high for cold temp.