normanvette

Can anyone tell me what the difference is between the C4 J55 brakes and C5 brakes?

pologreen1

C5 will out perform them, and I believe it's cheaper if you use them a lot in the end.

normanvette

Are the J55 and C5 the same size?

pologreen1

look at pics and threads about C5 brakes and you'll see the differences.

IMO just get C5 brakes especially if it for performance purposes. Calipers, more heavy duty rotors, better, better, better...

93Rubie

They both use 13" rotors with twin piston calipers but the C5 I think has more surface area and the caliper is larger. They will not fit under a standard C4 17" without some modifications to the caliper (grind) unless you are running an A-mold wheel. The J55 will work with any 17" Corvette wheel.

The C5 setup is superior but unless you plan to do a lot of autocross or road course track use, they are unnecessary on a street car, you will not see much of a difference. Unless you have a 84-87 car with the small 11.5 inch brakes. High quality pads are the biggest thing and good tires.

normanvette

I just purchased a 96 and plan to autocross and do track days with it so the C5 brakes sound like a good option. I am new to vette ownership so can you tell me what a "A-mold wheel" is?

pologreen1

There are plenty of threads on this, do your research. Look at pics of the rotors and calipers and you'll see.

The fronts are really all you need and some adapter brackets, the rest is pretty much the same for install.

mako41

Here's a link with excellent information and pics that show the difference between the J55 C4 & C5 front brakes. https://www.superchevyperformance.co...les.asp?ID=124

Here's an e-bay link to a forum member that sell the custom C4~C5 adapter brackets you will need to do this upgrade, http://cgi.ebay.com/ebaymotors/ws/eB...d=253707831396 His forum name is 76LS1BIRD, you might want to contact him through the forum, (Private Message) for a better price.

jaa1992

Crimeny - If you want C5 brakes go ahead and find one of the vendors that sell the abutment bracket and buy some calipers and rotors.

In my experience a 15 min session at Road Atlanta - me on J55, C5Z06 in front of me.
Both of us going 130/140 down the hill to turn 10A (look at a track map)
The Z06 is braking at about 150ft, I'm braking about 175 (I outweigh him by a few hundred pounds). We can do this over and over again. After 12 min I'm getting a little fade, the Z06 is not. We are both on Carbotech XP12 brake pads.

So going to C5 brakes costs me points, going to a willwood is the same points.
The J55 is almost as competent as the C5 brakes. Why would you got to C5 brakes vs a big brake kit?
I don't know - thats why I sold my c5 conversion brackets and am working on a big brake kit.

shakedown067

Get C6 calipers, they have the same bolt pattern as the C5, but resist spreading much better.

jrzvette

A-mold wheels are the 5 spoke wheels that came on the 95 ZR1. They were also part of the 96 Collector Edition (silver) and Grand Sport (black) option packages.

BTW, the J55 and C5 rotors were both the same diameter, but the C5 rotors were thicker; 1.25" vs 1" for the J55.

jaa1992

A strong suggestion - DO NOT CHANGE ANYTHING BUT FLUIDS AND BRAKE PADS!

Run the car that way until you have 10 - 20 hours of seat time (about 5 - 10 HPDE weekends). Then decide what class you want to compete in. Then and ONLY then make a modification plan, budget and stick to it.
Safety gear is the only exception to the "do not change anything" mantra above. A good seat, rollbar or cage, harnesses, fire extingusher will help alot.

c4cruiser

If you are just starting out, then SEAT TIME will give you much more benefit than spending money on mods right away. Do a complete brake fluid flush using a good DOT-4 fluid (ATE Super blue, Motul, and others) and install a good set of performance pads. Most autocross events don't really need anything more than stock pads or you can go with something like Hawk HPS pads or a similar pad type from CarboTech. It can't hurt to install new stock rotors as rotors and pads are maintenance items for track day junkies. Stay away from the drilled/slotted rotors; most of these will crack after some high-speed use like you will see on track days.

Make sure the suspension is in good shape too. Ball joints and tie rod ends need to be tight. Hubs need to be in good condition. Check all the bushings to make sure they have not cracked to where they allow too much movement.

As far as the "A-Mold" wheels, they are called that because that's the name of the company that made the 5-spoke wheels for Corvettes. The 95 ZR-1 and '96 Grand Sports and Collector Edition cars had them too. There are aftermarket companies that make a version but are heavier. Go to that online auction site and do a search for "Corvette wheels".

Tires can make a big difference in the performance and handling of the car. There are some very good sticky street tires that will help you for the first couple of years before you start to think about race tires. Look at the Nitto NT-05 or Kumho Ecsta XS for a low-buck/high value tire. The '96 with the Z51 suspension had the same size tire and wheel at all 4 corners: 275/40-17 tires on 17x9.5" wheels. If you go with that setup, you can rotate the tires for longer tread life.

Oh, and get seat time. Lots of it.

SEAT TIME!

mike100

I went to C5 brakes on my 91 because:

1) One of my J55 calipers needed rebuilding/replacement from previous track sessions.
2) the previous owner already purchased C5 calipers,mounting hardware and the adapter brackets leaving me to buy lines, rotors, pads and small hardware only.
3) The car already had genuine A-molds.

So for me it was economical. The one advantage of the C5 stuff is that replacement pads and rotors are nearly half the price and in-stock everywhere. They work nicely on my car, but I can't compare too well because my J55 stuff was in bad repair.

stonewall221

So if you do the C5 Z brake upgrade to your C4 the stock 17's wont fit :/ i have a set of ZR1 sawblades that i wanna use as street trim and i want to get a set of A-molds with a nice set of NT01's for the track? am i gonna have issues with wheel fitment or should i just upgrade to J55 or just keep the stock set up and upgrade to better rotors and pads? sorry guys im still relatively new to this and i want to start getting into track days at firebird. ive been looking into joining Arizona Corvette Racing but we'll see

Alan777

Your options are

1. Stick with J55 and use your street/track wheel and tire setup

2. Run C5 brakes and stick with the A-molds.

Like the guy above me said, flush your fluid, check your rotors and pads. Get some time on your stock brakes first, before upgrading.

stonewall221

alright thanks Alan, I just wanted to make sure before i went and put Z06 brakes on the car and then had issues throwin the wheels/tires back on. I really want to start getting some track time too, anyone going to Firebird in Chandler, AZ for the track days in mid Jan 2012?

radar502

The C-5s will stop you ...The C-4 sometimes will sometimes not...That's @100mph out of shape going into sharp left hander,,If you don't drive like that rebuild your C-4 stuff get a set of good pads and stanless lines help to...

stonewall221

Lol, so I was doing some more research and I think I'm gonna stick with C4 brakes, mainly cuz I want to keep the ZR sawblades I worked so hard to get (thanks to Shawn @ corvettenutz) but I saw that there are two variants of J55 callers, I really like the look of the GS J55's but are they worth the extra green? I do want to upgrade to stainless lines a dot4 synthetic fluid too but I wanna get all the knowledge first :P thanks again guys for the assists
Stonewall221