Building a 986 S for SCCA CS Autocross for National competition

[thstone]

Originally Posted by SCCA_AX

Normal autocross typically has a turn right off the start to attempt to minimize launch advantage. You also can start at your leisure, because you have to break the start beam to start the clock.

Pro Solo has an actual drag tree and at minimum 100' before the first turn. Timer starts when the light turns green, reaction counts.

Pro Solo is kinda like autocross on cocaine.

That is awesome! I have done a couple of road course races with a standing start - when the whole field does a drag race its pretty exciting!

[lawren]

I have my first autocross (SCCA STR Class) in a few weeks. I was wondering if someone could give me some tire pressure recommendations for:

1998 Boxster Base Model (2.5L)
Stock 17"x 7" fronts and 17"x 8.5" rear wheels
Bridgestone RE71Rs (225/45-17 front & 255/40-17 rear)
Front LCA (this is my only suspension mod at this point)

[SCCA_AX]

Originally Posted by lawren

I have my first autocross (SCCA STR Class) in a few weeks. I was wondering if someone could give me some tire pressure recommendations for:

1998 Boxster Base Model (2.5L)
Stock 17"x 7" fronts and 17"x 8.5" rear wheels
Bridgestone RE71Rs (225/45-17 front & 255/40-17 rear)
Front LCA (this is my only suspension mod at this point)

I wouldn't sweat it too much, the RE-71R is pretty pressure agnostic. Start at 35-37 square. Too much pressure (40+) and they get a little too sharp / antsy. Too little pressure and they just burn off the shoulders quicker, but aren't really any faster or slower.

If you go further down the STR rabbit hole and start running lots of camber you can probably start dropping down to the low 30s, especially in the front, and see time gains. Gotta test though.

FYI, if the tires are brand new, they tend to take an event or two to really hit full grip. Street miles don't speed up this process. Then they're pretty consistent until the tread is almost gone, as long as you don't cook 'em at a track day.

Good luck.