Mitsubishi Evolution IX - Project Evo IX

Many companies make upgraded brake systems for Evos but we choose to stick with Brembo's GT kits to upgrade our front and rear brakes for several reasons. The first reason was engineering. Brembo is an OEM supplier and their brakes meet stringent OEM quality standards. Brembo is standard equipment for most of the exotic cars built on the road and most ultra high-performance road cars for that reason. Brembo is also one of the standards in braking performance in the motorsports world, from F1 to MotoGP. The second reason is that our car is being built to be a bit of a sleeper with all of the mods having a low visual profile from the outside. Although our brake system is eye catching, so is the stock Brembo system. The uninitiated can easily overlook our brakes.

When evaluating front brake kits we chose Brembo's top-of-the-line GT kit with a huge 355mm front rotor and huge six-piston monoblock front calipers. This is the biggest thing they could fit under our 18-inch Volk CE28N wheels. One of the best things a genuine Brembo kit has over many other performance brake kits is that the Brembo kit is engineered to maintain the correct hydraulic proportioning. Brembo matches the caliper piston diameters so that the correct hydraulic ratio of front-to-rear braking force in maintained in all of its kits. A side benefit of having proper piston matching is that the pedal stroke will stay correct as well. Many other kits simply use an off-the-shelf racing caliper, usually with more piston area than stock. This results in the brake system having too much brake bias and a mushy long brake pedal to boot. Poorly engineered kits often have significantly worse stopping distances than stock for this very reason. We once drove an Evo from an unnamed company in an Evo tuners shootout event and were dismayed to find that the fancy-looking huge brake system on the car was way worse than stock for this very reason.

Brembo calipers also feature differentially sized pistons. What this means is that the front, leading edge pistons are smaller in diameter than the trailing pistons. The reason this is done is to reduce taper wear of the brake pads. Brake pads, especially long pads like the ones found in our front calipers, tend to use and wear the leading edge of the brake pad more heavily than the trailing edge. The front leading edge of the pad bites harder and wedges itself to the rotor due to the tipping moment (or lever arm in non-engineer speak) between the wearing surface of the pad and its backing plate resting against the caliper piston. The rear area of the pad is somewhat unloaded due to this phenomenon and is also lubricated by the boundary gasses of the vaporizing pad material created by the leading surface of the pad. This results in the front surface of the pad wearing faster than the rear, or taper wear. With differential piston sizing, the hydraulic force is less in the front with its smaller pistons and greater in the rear of the pad with the larger pistons. This compensates for the uneven forces acting on the brake pads, which will now wear evenly across their face. In some cases the brakes will actually be capable of producing more braking force as well since the pad is being used more efficiently.

We chose the Brembo monoblock caliper because of its superior stiffness, which will yield a firmer brake pedal. A monoblock caliper is just what it sounds like, a caliper machined from a single solid aluminum casting. Although it is much more difficult and expensive to machine a caliper like this, the performance gains can be worth it for the serious enthusiast.