GiroDisc Titanium Brake Pad Shims 2004-2021 Subaru STI

Description:
These Girodisc titanium shims are placed between the back of the brake pads and the pistons to keep heat from transferring into the pistons and fluid. Available for the front and rear calipers for the 2004-2017 and 2018-2021 Subaru STi models. Sold as a set for front or rear. Purchase includes four shields.
The problem of brake fluid boiling is simply traced to heat transferring from the rotors and pads directly into the fluid through the caliper pistons. When brake fluid boils, it releases air that is normally part of the molecular structure of the fluid. This air is compressible of course, and the brake pedal goes to the floor instead of moving the caliper pistons. Production cars tend to suffer from this on track days more as they don't usually have the extensive cooling duct and exotic brake materials as true racing cars.True racing only brake calipers generally come with titanium caliper pistons for one reason. Titanium as a material, has low thermal conductivity. This means that it is very bad at transferring heat. Which is good if you are trying to keep your fluid cool.
The Girodisc solution to help prevent fluid boiling is to use a thin titanium shim placed between the pad back and the pistons, to keep the braking heat from transferring into the pistons and fluid.Here is a comparison of materials and their relative thermal conductivity ratings:

Features:
- Full Set of Shims Per Location either Front or Rear
- Aids in preventing fluid boiling by using Titanium Shims
- Water Jet cut to exact size, no cutting, grinding involved

Specs:
- Titanium 6AL-4V 6.7 W/mk
- Steel 52 W/mk
- Aluminum 130 W/mk

Applications:
2004-2017 STI Front = TS-1001
2004-2017 STI Rear = TS-0961
2018-2021 STI Front = TS-1365-4
2018-2021 STI Rear = TS-STI-R