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Unread 01-25-2017, 01:25 PM
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Fair! Fair! is offline
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Join Date: Jul 2004
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Default Re: Powerbrake Big Brake Upgrade Kits from Vorshlag

The mid-sized X-Line "Big Brake" kits offered by Powerbrake use the larger X4EM 4-piston caliper. These kits are made to work as a front brake upgrade for "medium" sized vehicles like BMW 3 series, 350Z, and other sporty/sports cars that are bigger than the "Miata classes" cars.

These kits include rotor discs ranging from 330 - 356mm diameter and 32-34mm thickness. These X4EM calipers are also packaged as the rear caliper to go along with the Powerbrake 6-piston front upgrade kits.

This X4EM caliper is very similar to the Powerbrake front brake kit we used on our 2001 BMW 330Ci race car, which still fit under a Forgestar 17x10" race wheel, as shown above. You can read more about the install on our shop E46 330 starting here. Not all 17" wheels will fit over the X4EM caliper and associated rotors, but it is possible - we have the wheel fitment template for the X4EM caliper/rotor for many cars. Once again, Powerbrake recommends caliper and rotor sizes that fit the car's weight, speed, and classing needs.

These more larger X4EM 4-piston calipers are have even more thermal mass to deal with significant track abuse on heavier cars. We have beaten the absolute piss our of our E46 330 at NASA race weekends, often with dual drivers taking the car out back-to-back for nearly endurance racing levels of abuse. Driving this car at 10/10ths qualifying pace on every lap, using Powerbrake's track oriented pads, we have never been able to fade them.

The images above show the X4EM Powerbrake caliper and X-Line rotors next to the OEM front discs and calipers from the E46 330. The larger 4-piston X4EM caliper is a massive upgrade over the stock bits yet were still lighter than the original parts.

This 4-piston X4EM caliper uses the FMSI D810/D968 pad profile, which is shown in the image above at right. Powerbrake offers a number of pad options or you can use a brake pad brand you already know and trust by using this FMSI number or looking at the list of brake pad part numbers in the drawing.

Last edited by Fair!; 02-01-2017 at 03:41 PM.
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