vincent ashton

Will J55 brakes calipers and bracket fit on an 85? Would I need some other type of adapter too?

leesvet

Nope...

First you will need 17" wheels and possibly spacers depending on the wheel.. You also have to have the bigger rotors.
THEN you can look at adaptor brackets, abutment brackets, calipers, all the new bolts and hardware.
After that $1000 worth of stuff...get yourself some stainless steel lines for all corners or the works been wasted. Last, a new master cyl (w/booster $350) because the old one does not move enough fluid to compensate for the MUCH larger caliper piston space in the C5 brake calipers with dual pistons (Z06) or J55. Many folks complain of a brake pedal that is lower and runs out of travel before good stopping power comes up. It just takes moving more oil to the bigger caliper. It is worth doing though,...its just not simple as bolting the new calipers on.

BADDUCK

I have J55's on my Z51. They aren't anything to brag about. I would just invest in the best pads you can find and turn or replace your rotors. Also stainless braided lines will help as well.

rodj

J55 calipers clear factory 16 x9.5" Enkei rims fine (without adapters )

calvinlc

Hmmm....I just replaced my rotors and pads on all 4 corners this weekend and flushed with Motul RBF600 fluid. I guess I think they do pretty damn good. In comparing it to my 2001 Audi S4 with $2,000 Stoptechs, I would say these stop within a few feet of those. Now we will see what happens when I take it out to the track, but I am optimistic. I am running the Stoptech pads which I have found work very well for a driver/track car (340 HP, 3550 lbs), even on a 2.5 mile track. Just my opinion so far.

--Calvin

leesvet

yes, Enkei of a specific casting...not all.

one is conical and the others are not. The amount of extra space is only a couple MM....Thats why everyone goes to 17 so they can have some other options.

rodj

In 10 years , never seen anyone with Enkeis state they can't fit a J55 caliper


And the supply of aftermarket 17" rims with correct offset for early cars is limited and not everyone wants to run adapters

gerardvg

I have fitted ZR1 13 inch front disc rotors and twin piston calipers
with adapters. You can use the early master cylinder,
You will need an adjustable brake proportioning valve to stop the rear wheels locking up. Or change your bias spring in the master cylinder.

The 88-96 master cylinder i purchased for the job did not fit as the 85 had a extra brake line port.

I set my adjustable brake proportioning valve and all is good,

I already had the 17 inch A mold wheels on my car before the brake upgrade.

LaVidaLoca

I did this a number of years ago. Here is what I found out:

1. I used some 17" A mold wheels with the proper offset. The stock wheels would not work. Not sure what others might work.

2. The brake caliper has to move outward to allow for the larger diameter rotor. It also has to move laterally because the rotor is also thicker. This is complicated by the larger caliper size needing to rotate slightly.

3. You must replace both the rotor and the calipers.

After having done this mod I would advise against it unless you can get the caliper / rotors REALLY cheap. Better to go with an upgrade package that will just bolt on. The stock 85 brakes are really weak. Going to the J55 plus a 9.5" front tire was a huge improvment.

Look at my Flickr account. I show the brackets I machined to do the job and some pics on how I did it.

http://www.flickr.com/photos/1757654...7602879432548/

There are some adapter brackets you can buy to do this but it adds about $200 to the cost of the project.

gerardvg

I got my ZR1 brake disc's calipers and adapters for $190 on ebay Australia a few years back Like new discs and calipers
Well we can be lucky some times, people did not notice they were the 13 inch brakes I snapped them up pretty quick smart

leesvet

huh? 99% of aftermarket rims these days come with the correct offset. For those that want to remain pure to the breed, various other Corvette rims like the sawblade need an adaptor. Thats just something you have to get over if you want that wheel. In 24 years of owning C4s I've never seen a sawblade clone.......but I've seen a thousand 84,85,86 & 87 owners upgrade to 17" and the sawblade was the obvious choice for almost all of those years.

rodj

I was referencing 17" aftermarket rims for early cars.
In recent times ,only AFS made rims with the correct 38mm offset to suit these.

leesvet

I think its the spoke ZR copies that I see ready to roll...Like I was saying elsewhere, I thought it was a law that they make no other wheel than the 5 spoke of some sort.. and seems like everyone wants to have ZR1 wheels..persoanlly, I am not a fan of the spoke.