Quote:
Originally Posted by Bob Eyres
I've got a 65K mile 91' ZR-1. And it's been sitting in the garage for way too long.
We're waking it up, changing all fluids, and trying to freshen it up overall for the summer.
The brakes are all original. Only one pad replacement since the car was new. Front rotors look o.k., but the rears are worn.
While bleeding the brakes we found that the front caliper was clogged and wouldn't bleed. We're going to pull it off today and see what's up.
I'm wondering what you guys have done to rehab the brakes on your car, and who offers the best deal on parts.
Before you tell me to go out and get a set of drilled or slotted rotors and three or four piston calipers, I've got to say that I'm generally happy with the stock brakes, and their performance. And I really like the bone stock look, no flash.
The only thing I would do to change it is possibly put on stainless braided hoses, as they might give a firmer pedal. (Do they?).
I'm thinking, rehab or replace the calipers if they need it, new rotors for sure, (stock), fresh pads (what kind for normal driving?).
I do like to drag race, but don't spend a lot of time at top-end, or slamming through the twisties, (there aren't any here in Fla.) No track days either.
Who offers the best, cost effective package for the ZR-1. Cost is a factor here.
What do you think? 
Thanks in advance.  |
Hello Bob
Allowe me please to tell you something about brakes.
I understand when it's about a brake update, many ZR-1 owners don't want or can't afford to invest money in driving security. But keep certain facts in mind:
When you want a firmer pedal, with new stock or stainless braided hoses you won't get it. The reason is, especially due aging the caliper use to spread a bit more than new ones.
Some low-budget drivers suppose when they install a C5 upgrade it will become significant better, but it also isn't the case. The reason here is the C5 caliper pistons have a bigger diameter and also a bigger volume. The pedal can't become firmer due to a volume imbalance between the main brake cylinder and the caliper volume. Another point is, the C5 calipers also do spread a bit.
I have customers who did a C5 upgrade on their ZR-1 but soon changed back to stock because the result wasn't satisfying.
The solution is to go with 4 or 6 piston brakes when you consider a upgrade, and I am not talking about the C6 Z06 brakes because its piston volume is adjusted for the C5 and C6 brake system but not for the C4. These brakes are mainly good for a nice show behind big open rims.
Porsche recommend to go in high performing cars up to 500 hp at least with 4 piston brakes at the front and over 500 hp with 6 piston calipers. Additionaly a update at the rear can also be installed but that is something for those who race or have money to spend.
I wonder how people can spend alot of money in big cubic inch motor upgrades but don't care about a significant better stoping performance. Today's middle class cars have even better brakes than our ZR-1's. In my opinion it's like a playing with the fire. Some guys believe they are experienced drivers and can handle with the very most traffic situations. But the unexptected is often unpredictable and it can depend in a emergency case on just some feet or inches. The stock brakes are good for 1-2 hard stops from 60-0 and that was it.
I do work together with the german brake manufacturer Mov'it (take a look at:
http://www.movitcars.com/rahmen/corvette.htm) and we developped for the C4 a fit bolt on brake system for all 3 different stock 17 inch rim designs. You can install the 4 or 6 piston brakes without to have to replace the stock rims.
By the way: One of my clients run with sawblade rims and want to sell his black 4 caliper 322 x 32mm Porsche front brakes with about 4'500 miles on including all holders, screws and stainless braided hoses.
He is going to upgrade his brakes to 6 piston calipers (with 342 x 32 mm rotors) at the front and 4 piston calipers (with 322 x 28 mm rotors) at the rear for his new 427 engine.
If you or anybody else is interested in this kit, let me know.