i cant find anything that specifies the differences in caliper # of pistons and rotor size on here. maybe i just missed it. the pinned thread with all the specifics on the changes in years wasnt really specific about these things. i was wondering if the 88 GTU has the same calipers as the TII. i havent had a chance to look yet.

thanks

 

If I'm not mistaken, the GTU and TII have different sizes..but then again, I am not the best choice for answers.

 

The 88 GTU model had the same brake calipers and rotors as the TII's. The S5 GTU models had different brakes than the TII's.

 

There were 2 different types of brakes; small and large. The 86-87 base, 88 SE, 89-90 GTU, and most of the 91 nonturbos (there were no NA trim levels that year) have the small brakes, which consist of a single piston caliper up front and a non-vented rotor in the rear. The 86-88 small brake cars were 4 lug, while the 89-91 small brake cars were 5 lug, but the brake calipers themselves were the same, and the rotors were the same diameter, just drilled differently for lug pattern.

Everything other than the above models got the 4 piston front/vented rear big brake setup. This includes all turbo, convertible, gxl, and the various "sporty" models throughout the years.

 

thanks kevin

 

That's not entirely true, the 5 lug 4 piston brakes use the same front rotors as the 5 lug single piston breaks and the 5 lug 1 piston cars also have larger rear rotors than the 4 lug cars.

 

By what...like 1/4"? What does it matter...for all intents and purposes, they are the same thing. Here I am trying to simplify things for people and you're complicating matters for them.

 

If switching an 86 base from the solid disk to the vented disk, will the same rear calipers fit?

 

No, because obviously the disc is wider, the pads are teh same thickness, so the caliper needs to be wider as well.

 

It does matter when you're looking to buy parts and get all confused when there's no small 5 lug rotors.

 

I dont know about you, but I would certainly consider a thin, non-vented rotor to be "smaller" than a thick, vented rotor, as well as the different calipers that accompany them. But that's just me.

 

The fronts then.

Anyway, the point is that they're different, plain and simple, there's not really much point in arguing over how much difference it makes.

 

Well, let's see. There's 4 main parts of the brake system we're talking about. Front rotor, rear rotor, front caliper, rear caliper. OF those 4 parts, 3 of them are small on one version, and larger on the other. To me, that sounds like a "small version" and a "large version" even though one part does in fact cross over.

I stand corrected, I guess.