[scottj]

The SL6 (1.62/1.12/1.12) piston area = 4.03 sq. in
The SL4 (1.88/1.75) piston area = 5.17 sq. in.
That should give the SL4 more clamping power. Although, the smaller bores in the SL6 may give it the edge in rigidity over the SL4.

I went with the Wilwoods also but I used the 6-piston GNIII caliper with a 13 x 1.38 rotor in front and a Forged Billet Superlite (1.25/1.25) with a 12 x 1.25 rotor in the rear. I also used dual masters and a balance bar. I use PFC 01 pads, Castrol SRF fluid, and air ducting to the fronts. Obviously, the faster you're going and the harder you're braking the more heat you're going to generate. I went through a couple of brake setups before this and found them to be unable to handle the heat after 2 laps. Lighter rotors are of no benefit it you can't slow down. This is the only setup that I've been able to run 30 minutes all out without fade.

Scott