The Perrin master cylinder support brace for the 2008-2014 Subaru STI provides the much needed support for the master cylinder and brake booster that the stock setup just can't provide. When force is placed against the brake pedal, the brake booster and master cylinder will actually flex, and over time can fatigue to the point of failure. The designers at Perrin have devised a simple plan to fix this problem; a brace cut from 6061 aluminum that bolts to the driver side shock tower that is not only easy to install, but also inexpensive. With the Perrin brace, tension is now directed toward the master cylinder, eliminating damaging flex. This modification will produce a noticeably firmer brake pedal, without any risk of damage to the firewall.