So I have an 1987 SE with a DOHC 3.4 swapped in. Brakes are stock but I would like to upgrade them. I know typically guys go with Grand am or all out with Corvette.
I happen to have an 1989 Firebird Formula parts car with the nice PBR 4 wheel disc brakes. Anyone ever swap these to a Fiero? Or are there issues besides mounting them up. Obviously I would need to change bolt pattern or modify rotors to fit the fiero to get them on. Thats fine. I'm mainly wondering if anything else would need to be done. Changes to Master Cylinder/Brake booster?
I haven't looked up the bore diameters of the calipers (front/rear), but most cars run a substancially smaller rear caliper than the front to obtain the vast majority of the braking bias front/rear. All fieros use the same (or nearly the same) caliper diameters front/rear and use the combination valve to adjust the bias.
So if you just swap on a set of calipers with larger front bore, smaller rear bore you will increase the braking in the front while reducing it in the rear, which isn't a good idea. Once you get past the caliper issues, then you need to look at the depth of the rotors... almost any depth will work in the front, but the rears are very tight. I have made a 2.10" deep rear rotor fit the rear of an 84-87, but it required some clearance work to do so. The C4 rotor that most use is about 1.97" deep.
As for the hubs, anything with the 4 3/4" bolt pattern has a larger rotor pilot than the Fiero, so you will need some concentric rings of the appropriate thickness.