bretcopsey
01-04-2008, 08:42 PM
I picked up a set of four calipers for a 2002 Trailblazer at a price considerably less than what C5's have been going for. The front calipers are twin 45mm pistons. Should these be comparable to the C5 stuff?
bretcopsey
01-05-2008, 05:41 AM
Can they work?????
My initial tinkering with them seems to indicate so. They fit the 13" C4 rotor, and I should be able to fabricate a bracket to attach them to the spindle.
Apogee
01-05-2008, 02:24 PM
I'm not sure what you mean by "comparable", but they are a PBR Slimline caliper, gravity cast instead of pressure cast, and have the larger 45mm pistons as you already mentioned. I believe the Trailblazer/Envoy (2004-ish) front rotors were 29mm thick new, so that's probably the maximum thickness for the caliper/PAB combination you have. The13" C4 rotors are 28mm, so probably not a bad comprimise.
My question would be why you would want to use such large pistons on a relatively large diameter rotor? The larger pistons will give you more clamping force and therefore brake torque with less pedal effort...but that only helps up to the point that your tires lose traction and start skidding. Smaller pistons give better pedal feel and feedback to the driver, thus explaining why the C4 Corvettes are 38mm and the C5/C5 'vettes are 40.5mm pistons. Even the 98-02 F-body calipers are 43mm but they're being used on 12" rotors, so the brake torque is actually much closer to that of the C5/C6 setup.
Congrats on thinking outside the box though. Hope it works out for you.