The time has come for brakes with higher thermal capacity and less caliper twist/deflection. After reviewing several options, I chose the AP Racing front brake kit from Urge Design / Essex Parts:
This kit uses a very lightweight and stiff 4 piston aluminum caliper and 32 mm thick 60 vane floating rotors. Because the rotor diameter is 299 mm (same as stock), diametrical wheel clearance is fine. The thick caliper combined with 20 mm thick pads do interfere with the spokes on my 17 X 9.0 ET45 Enkei RPF1’s. To accommodate the brakes, I purchased TSW Interlagos wheels in size 17 X 9.0 ET63 which clear with less than a 10 mm spacer but I’m running a 15 mm spacer to maximize front track width without additional fender modifications.
This kit was impressive right out of the box with high quality hardware and nicely machined and finished rotary mount adapter brackets. Everything bolted up perfectly with no alignment shims necessary.
I installed Hawk DTC-70 pads and bedded them in per Hawk recommendations. Then it was off to Pacific Raceways for a two day NASA Time Trial event. Brakes performed flawlessly. Bias was spot on and feel was great. With the stock calipers, the pads would develop a taper due to twist in the caliper (likely the guide pin interface for the floating caliper). With tapered pads, feel is compromised as the pads don’t fully contact until the caliper is loaded enough to flex. The Urge Design AP kit had the same consistent feel from the first stop to the last stop of the weekend after nine 20-minute sessions. I dropped my fastest laptime from 1:30.3 to a 1:28.1. Pad wear was surprisingly minimal. Previously, I’d use up new pads (Cobalt XR2’s) in about 12-14 20-minute sessions.
So far, the rotors are also holding up to severe track abuse. Pacific Raceways has several high speed sections followed by heavy braking zones including slowing from 147 mph to 70 mph for Turn 2 and slowing from 120 mph to 45 mph downhill for Turn 3.
Rotors hit temperatures between 1075-1326 F according to the indicator paint.
Calipers didn’t even register on the temperature indicators with temperature of range of 300F-500F.