How come they arent allowed? There are turbo cars in T2 (EVO,WRX) and cars with more HP in ST and T1, I'm almost positive that one could compete in T1 with a 996 turbo (and probably win some with an x-50) based on the the modifications list:

ECU
Exhaust w/out cats
Rear Wing
Removal of AC and related components
Racing Seat
Camber (up -2*)
H&R Springs
Hoosiers
Roll Cage
Steering wheel
Brakes ducting


Not to mention the weights of the turbo are a hinderance anyways and they could always adjust them

 

SCCA wants to avoid specials that aren't available to the
general public so in various specs they require cars to
have been made in certain quantities. In autocross,
it's 2,000 per year at minimum, so the turbo fails, and
is slotted as an SP car right off the showroom.
Joe

 

Not arguing here but the Ford GT is in Super touring and I thought Generation II Vipers were only made at 1800 per year, also the 996 GT3 is in the T1 class as well and I would bet more turbos have been made than GT3's.

 

I'm with you... There must be some other reason (too?) I
am not naive or even offended about the political clout of
American car contingents in SCCA. In autocross it seems
there is always a class where every remotely recent Corvette
will be competitive.