Going to Smaller Front Brakes Question?

[Jim Doak]

I thought that I'd ask here and the other forum before I dig elsewhere...

I have SN95 Mustang Cobra brakes and spindles, including the 13" front rotors on my Mark I.5 FFR. The 13" brakes require at least 17" wheels but I'm thinking about going to 15" wheels. Here's my question: Can I simply replace my front 13" Mustang Cobra rotors and calipers with SN95 Mustang GT rotors and calipers in order to fit 15" wheels? Or is it more involved than that?

Thanks.

[Mustang Man]

Jim, the SN-95 spindle is the same for V-6, GT, and Cobra-spec brakes. The GT rotor and caliper WITH caliper mounting bracket will swap right over. Perhaps you can find an owner with GT brakes looking to upgrade and swap parts for a no-cash upgrade!

HTH...
Mark

[Jim Doak]

So Mark,

Are you saying that the GT and the Cobra use different caliper-mounting brackets?

(By the way, I just resubscribed to your magazine and read your article about converting from a carb to throttle body fuel injection. That's another project I'm considering since I installed an in-tank fuel pump last year. That FiTech system has peaked my interest.)

[Norm B]

Jim, the GT uses a different caliper bracket. All the ones I have seen have a 15 stamped into the top.

HTH
Norm

[Gumball]

Jim,

I did this exact swap during my build, which has spindles from a '94 SVT Cobra and had the 13" brakes. I originally was using the 17" FFR wheels, but my build took a turn to old-school and I just had to go with the 15" wheels. I found a full set of the stock GT brakes from a guy who had them left over from his complete kit (never opened) and it was a pretty simple swap. Watch out for a little contact with the spindles, though, as a bit of grinding is necessary to clean up the castings and make it so the calipers can slide smoothly.

I didn't change anything else - the master cylinder is still the new '94 version that FFR sells and there is no proportioning valve in the system. The rear brakes remain the 11.65 units from the '94 SVT Cobra donor.

I'm very happy with brake performance, but it does take a bit to get used to the non-power assist force needed and you should experiment with pad compound to get the balance that works for you.

[Mustang Man]

Yes Jim, the caliper brackets are different, as the Cobra needs to "reach" out farther for the larger diameter rotor.

Also, the '94-'98 GT caliper is a true bolt on. If you go with the '99 and up GT caliper you'll need to do the minor grinding/clearance mod that Chris mentions in his post above.

HTH...
Mark

[Jim Doak]

Thanks guys, that's what I needed to know.

And Gumball, I like your username. (You'll see why if you open the attached photo of my car.)