Performance Friction’s Killer BMW 135i Brake System. Track Tested, Street Durable!
By Mike Kojima, photos by Jeff Naeyaert
In a Time Attack car, the brake system is just as critical for a winning car as the engine. The same is true for a street car but under differing parameters. A successful race car has to slow down rapidly and repeatedly from high speeds. A street car has to do the same but for 100,000 miles with little maintenance.
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| The Performance Friction kit is very complete with all of the parts and hardware needed for installation. |
The Berk Technology Time Attack BMW 135i is definitely a race car; it was designed and built to be a rolling test bed for Berk’s line of high performance parts. The car is a terror in Redline Time Attack’s Street class. The rules are such that a car run in Street class is still legal for highway use. To emphasize this, Street class cars must have a valid license and registration. The Berk car is actually quite streetable and if it was not for the roll cage would be a very well mannered uncompromising machine on the road.
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| The caliper body is forged from aluminum billet to near net shape for superior grain flow and alignment. This gives the best strength and stiffness by working the alloy. The calipers are a monoblock design with a large bridge which also aids stiffness. FEA was used to make the caliper body as compact as possible for the lightest weight and best wheel clearance. The large diameter piston caps shown here help equalize the pressure on the the brake pads and protect the pistons and seals from dirt and heat. |
Although the BMW’s stock six-piston Brembos were indeed quite good brakes, the team wanted more as the car continued to become faster. With the addition of extra stick from some Andrew Brilliant designed aero, in competition more braking power became desirable. From a marketability standpoint, in keeping with Berk’s philosophy of having everything on the car something they could stand behind with street customers, designing an upgraded brake system became a challenging engineering task. A new brake system had to not only work better than the stock brakes but also be fully streetable, compatible with the car’s electronic nannies and not require extra maintenance in highway use.
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| Perhaps the most interesting feature of the calipers is that each caliper uses 4 small brake pads, one for each piston. This stops taper wear and gives better initial bite. We will be using Performance Friction’s proven 01 compound for track use. |
