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AP Racing Four-Piston Front Brake Upgrade
We use this terrific front brake upgrade on our track Impreza. The kit consists of two AP Racing calipers, CNC-machined black-anodized aluminum mounting brackets, hardware, stainless brake lines, and two aluminum-center full-floating vented rotors, 12.8" diameter and 1.26" thick. Pads are sold separately.
We used to run the STi Brembo brakes on our track car, but found that we were going through pads very quickly, and rotors were only lasting about six track days before the high heat loads cracked them to bits. We switched to this AP Racing kit and have had much better rotor and pad longevity, zero problems with brake overheating, and terrific, reliable and repeatable stopping.
An additional bonus is that the calipers included anti-knockback springs in the pistons. Knockback is when cornering loads push the pads slightly away from the rotors, which can result in a few inches of unexpected pedal travel the next time you use the brakes. If you're on the track where every split-second counts, this can be scary. Again, after switching to the AP Racing front brake setup, we experienced no knockback.
The calipers are made of lightweight forged aluminum, anodized for durability and less color-shift than powder coating when used on-track. The pistons are stainless steel for light weight and low heat transfer. High-temperature, low-drag seals keep the pistons sliding freely. Pad replacement is as easy as removing a single bridge bolt. The pads slide out like toast from a toaster.
Have you ever fought a steel bolt that seized into the threads of an STi Brembo caliper? The AP Racing calipers feature replaceable stainless steel bosses for the bolts, so that particular problem is a thing of the past.
The brake pads are a full 20mm thick, compared to 14mm on the STi Brembos.
You save a MASSIVE amount of weight with the AP kit compared to an OEM Brembo setup. The two-piece AP rotors are four pounds lighter than a stock STi rotor, and the forged aluminum AP Racing calipers are three pounds lighter than the cast Brembo caliper. That's a total of seven pounds of weight savings per corner!
This brake kit is intended for track use. The pads are a track formula, and the calipers do NOT have dust boots for the pistons. (Dust boots would quickly burn up under track use anyway.) You can use them on the street, but they'd be overkill and the calipers will require rebuilding sooner than a street caliper. Oh, and they're pretty loud.
Fits all Subaru models 2002 to present. Note that this kit will require decent wheel clearance. If your wheels fit over STi Brembos, you should be fine. If you're not sure, give us a call.
|Pad thickness comparison14mm STi Brembo pad on left, 20mm AP Racing pad on right. 60% more friction material!|