Spec Boxster build @ ATLspeedwerks

[toddlamb]

Yep that's pretty much what we found too, except in SCCA T4 we expect to have weight added and a restrictor, so it would push it into the 1-3/4" category.

Having said that, for SPB 1-1/2" is more than plenty for the weight of the car, based on 15+ years of hundreds of Spec Miatas racing at 2350-2450# with 1-1/2" .095 resulting in zero tubing failures, and that's with only 8 allowed attachment points.