[Bill Verburg]

Originally Posted by VFR750

Continuing the Brake Upgrade Discussion with my thoughts and info.

Starting Point: 911SC, 2,900 lbs wet, est 215 rwhp, R888R Tires, Stock SC brakes & Hawk HT-10 pads, Motul-600 brake fluid

Problem: brakes are toast after every track day. Long pedal after cool down, Spongy and need to be flushed.

Also: frequently, I see the front bearing caps leak grease onto the wheels. Must be getting pretty hot to liquefy HT grease.

Pads look toasted too: Note the heavily checked surface, crumbling edges, and paint burnt off the back sides. (This happens after the first runs) HT-10s are very high temp pads by Hawk, not many more options except DT-60/70.


I read almost all of the Brake Upgrade threads. A lot of good info. Unfortunately, 930 brakes are no longer a cost effective option. The calipers, if for sale, are just not affordable in 2018.

Used Bill Verberg's data to see what I am getting into.

Researched the Stop Tech path, and concluded Level 1 (ST-42 caliper Front Only) really doesn't get much except a much wider front rotor. You have to jump to the Level 2, front and rear to make a real difference.

I am now thinking the Rebel Racing Boxster S/996 upgrade might just be the affordable upgrade.

The Boxster S/996 upgrade (front and rear) seems to offer a lot for about $2,400 investment: Gain 40% more pad area, 28mm wide front and 24mm wide rear rotors for heat dissipation. Need 930 master cylinder. Bias shifts forward, but can be compensated with higher friction pads in the rear.

A Hybrid configuration with Carrera rear Wide-M caliper gets the 24mm wide rotor, better bias, but you are stuck with the tiny brake pads

I color coded the parts by configuration, My SC = Yellow, etc.... And the pad area percents in yellow are the Boxster S/996 increase from stock SC area.

Mike, while I like the 996 front a full 996 setup ios still more front biased than I like to see. The main issue w/ that is it puts more of a load on the front and lets the rears loaf.

Stock SC has a torque bias of 1.491 which is right where you want it.
full 996 is 1.811
996 front w/ C3.2 rear is 1.743
930 is 1.579

Of these you stock are best except for the heat issue
to address heat
are you using A-arm scoops? Ducts tend to be too small to do much good unless they are really big.
are you using Castrol SRF?
what pads? I'm assuming you have track pads
changing fronts to the Carrera 3.2 calipers and rotors helps a little

993 can be adapted w/ not too much effort, they would use 930 rotors f & r, front caliper adapters are available and some slightly tricky but doable mods to the rear calipers bias is 1.572, you would want 16s for this