I've had this car for 25 years. Until this year, I ran nothing but tires and wheels on it that were stock sized or close.
For the entire time I drove it that way, I'd say the brakes were OK but not great. The pedal was soft feeling relative to other cars. But since they were factory you just think that's just the way they are and you live with it but I never liked them.
What really made it evident that the brakes were lacking was my wheel and tire change that I did earlier this year. I put a set of 16X8 GTA wheels and a set of pretty grippy tires on it. 235/55R-16 front and 255/50R-16 rear. After test driving with those new tires, it immediately became apparent I had to make a change. I could not lock the tires up at all in a panic type stop. Your instinct is to press harder on the pedal which then makes you notice you can push it nearly to the floor with a feeling that can only be described as mushy.
The first thing I did was buy a kit from Powerstop that gave me drilled and slotted rotors, new powder coated stock calipers and brake pads that they highly tout.
What garbage that was. The pads came apart on me during the brake-in procedure they gave me and I followed to the letter. I changed the pads back to a regular metallic but then I was back to no better than when I started.
So the next thing I did was buy a set of Wilwood cast metric calipers with oversized 2.75" pistons (versus the stock 2.5"). They were only slightly better than the stock ones but I still couldn't lock the brakes and still felt mushy when trying. It was at that point I put on the 11" booster and 1" bore master That didn't help at all. In fact it just made the brakes feel more mushy than before. Even tried a 1 1/8" master and that didn't help anything either.
At this point I tried this test. I used vice grips and clamped off the front brake hoses close to where they go into the calipers. I then started the car and hit the brakes. Got a very high and rock hard pedal. Couldn't be pushed down to the floor (or even close) no matter how hard I pressed with my leg. I gave it everything I had!
This told me the problem wasn't in the rear brakes or master. It was all in the calipers. What I believe is that metric calipers flex once the pedal pressure reaches a certain point. You just can't get much stopping power with them. More pedal pressure just makes them flex more.
So it was then I started doing this LS1 brake project. And yes, now I get a very high, super firm pedal that will lock up the brakes with ease. Feels just plain great!
