Monday, April 30, 2012

Brake upgrade for the Cayman S

After almost a year of tracking the Cayman, I had never really had an issue with "brake fade". But last time out, I finally got to experience what I had always heard about. I was about 25 minutes into a track session at Laguna Seca with Trackmasters (, I was heading into Turn 2 (Andretti hairpin), doing about 118 mph. I hit the brakes hard, but the pedal went soft on me and I went in too fast, went waaaaaay wide, and was happy there were no other cars in the turn with me.

For those who aren't into this stuff, a quick lesson on brakes and fluid: When your brakes get really hot, they can transfer that heat to the brake fluid. Brake fluid is hydrostatic, which means it tends to attract atmospheric water over time. When water is in your brake fluid, and then gets hot, it vaporizes and puts air in your fluid. Next time you press your brake pedal, instead of having that force transferred to the calipers, causing your brake pads to squeeze your brake rotors, the pressure merely serves to compress the air that is now in your lines (air compresses, brake fluid doesn't). That is when your pedal gets mushy, or in the worst case, just presses right to the floor and NO BRAKES! Not good at high speeds.

In racing, brakes do a great deal of work, and get very hot in short period of time. To combat the heat, you can: (a) have larger equipment to dissipate heat better, (b) use materials that are less likely to heat up, (c) have brake fluid that attracts less water and/or holds up to heat better or (d) direct more air to the brakes to cool them. I decided to do (e) all the above, if only because I am a wuss and never want to be without brakes at high speed again. The other key is to replace brake fluid often, to flush out any accumulated water.

So, if you drive a Cayman S, I can say this is an easy upgrade, only takes a couple hours to complete, and works great. Here is what I got:

Larger diameter Girodisk rotors
Pagid RS29 "Yellow" racing brake pads
Motul 600 Brake fluid
GT3 brake air-flow ducts (not shown)
Tools required: Torx 55 Bit (1/2" ratchet), torque wrench, brake bleeder, lug wrench, needle nose piers, hammer.

Here is everything you need for a fun day upgrading your Cayman S brakes:

The Girodisc people provide the spacers and longer caliper bolts to account for the larger diameter rotor:

Note the small cracks on the old(stock) rotors that were developing due to heat stress. No bueno…

Installed at each corner in about 20 minutes. Brake are pads held in by a cotter pin, a rod pin and tensioner. Caliper is held on by two bolts, and the rotor is attached with two small screws (and the wheel once it is bolted back onto the axle hub):
Finished look:

The brakes work great, and stop the car so hard that they are too much for stock tires (inducing lock-up). I look forward to putting the track tires back on to test the real stopping power of these babies!

This article discusses the process for removing and replacing the brake pads:

and this article discusses the replacement of the rotors:

1 comment:

  1. That's a brilliant design... At first I wondered why you would swap OUT the drilled rotors. The Girodisc design looks awesome.