I’m doing a light brake upgrade on the Fiero per http://myfiero.oceanmoon.com/how-to/brakes/the-easiest-fiero-brake-upgrade
This is a nearly bolt-on upgrade and involves using a caliper from an early 90s Beretta/Grand AM and some modifications to the OEM rotor/hub (pre-’87 Fieros have the wheel hub and brake rotor as a single casting).
I’ve taken some photos of the machining I did on the rotors. All work was done using a lathe.
For this rotor I had access to a large lathe so I grabbed the assembly by the rotor and used a parting tool to remove the inner hub from the rotor. There are other ways you would go about this on a smaller lathe (holding the part would probably be different, and possibly a different operation to separate the parts).
This picture is the rotor still in chuck after removing the inner hub.
Here is the inner hub right after separating it from the rotor above.
I used the smaller lathe in my shop to turn down the diameter of the inner hub to fit inside the Beretta/Grand AM rotors.
Here is the original hub after being turned down to the appropriate diameter. I also decided to face a few thousandths off the outer mating surface to clean up all the rust and old paint and make sure it was perpendicular to the spinning axis. It also makes it nice and shiny…
Here’s the original hub being set inside the new rotor.
Original hub fully seated in new rotor. I had about 0.005″ clearance. We’ll see if I regret that after a couple years of rust and racing…
New hub installed on the car, without wheel studs or the new rotors.
Preliminary testing indicates that facing off the outer mating surface just a few thousandths moved the rotor close enough to the heat shield that the rotor just barely rubs on the shield. So I guess some tweaking will be required there…