Gearheadotaku

After 3 track days on my xp10's, they have worn out with an odd pattern. The top of the pad is nearly to the backing plate while the bottom is still 1/3 remaining. The car is an '88 C4 with the J55 package. The calipers and rotors were new at the start of the season, and the pads have no street time on them at all. I've seen taper from front to back with other pads, but never top to bottom. I have small brake ducts on the car. I have regular street pads from carbotech on the back.

larryfs

they call that pad taper.

94ZR1#444

That's normal for the J55. I went through 4 sets of J55 calipers in 45 events. I have have splayed out my old J55's at least 1/2" at which time they were thrown away. The pad will taper top to bottom and from front to rear. Carbotech's will wear out even faster. Get rid of the J55's and get some Wilwood's and start using PFC01's.

AUTO_X_AL

Is a GS caliper any better than a standard J55?

So far we have yet to have any issue with the GS parts but I don't have anything to compare it with.

Carolina C4 Racer

The GS caliper is more rigid than the regular J55.
A.M.

Aardwolf

Here is a page showing detailed pix of the GS and J55:

http://www.superchevyperformance.com...4calipers.html

froggy47

If you are going for a stronger/stiffer caliper, then going from j55 to j55(Grand Sport) is not going to do much. Minimal differences. Mostly cosmetic.

I never had much of a problem with my j55's & pad taper, but did not track the car that much, mostly autox.

AUTO_X_AL

We went from a 11'' single piston to the GS calipers. Big help on track at least. Don't really think it helps too much at an autocross. The big down side is the 13'' brakes are 33% heavier. Seven lbs. per rotor more. I would much rather have more brakes than 14 lbs. less rotating mass.

Sidney004

Your calipers are indeed trashed. They have dimensionally distorted. It has happened to me with both the GS as well as the J55's. Getting Wilwoods will cure the problem permanently, but at the very least install a new(or used non raced, which is what I do) J55. Otherwise, you will throwing good money on pads away; by the way the total failure mode for this condition is a loss of brake pressure and fluid when the piston seal extends beyond the bore as the caliper continues to spread, it happened to me. Also, is it a right or left caliper, I may have a spare one I will sell you for $30 plus shipping; I buy used ones on Ebay and parts FS board.

Z06_BluByU

I'm about to do the GS conversion on my 1993 coupe for a few HPDE's I'm attending.. Robeling Road with PCA the 15-16th and seattime Nov 16th.. Is that gonna be the beginning of the end for these things?!? Hate to think I just dumped all 700 bucks into something that'll be junk soon?.. is there a way to mitigate this probelm? should I have stuck with the smaller stock pads?!?

94ZR1#444

You can mount the GS calipers (basically the same as J55) on the rears when you do a Rippie Wilwood big brake setup. Check out their Wilwood GNIII/ST setup. The GS calipers wear out just as fast as J55's. The pads are exactly the same on both GS and J55.

astock165

I would say no but that is one man's opinion. I'm in my 2nd season (a/x & a few track days) with the J55 conversion and haven't had any issues.

I think using a good pad combo will help with having to overwork the caliper.

96GS#007

Once you fall prey to track days, everything becomes an expendable....engines...hubs...brakes... tires

Sidney004

A key factor to reduce this caliper spread/pad taper with the GS/J55 would be spindle ducts and the associated air ducts. I got mine from forum member ZR1 MK. These ZR1 MK spindle ducts are compatible with the Wilwoods if you elect to upgrade.

AUTO_X_AL

Air ducts are a very good idea.

I have had the brakes glowing @ Gingerman (2000*+/-) with DTC-70 hawks on them and our calipers are no worse for wear. We beat our car with very little mercy and we have yet to really see any caliper spread or excessive pad taper. Personally I like the GS setup myself.

AUTO_X_AL

We are in our second full season as well. We have found the hawk HT-10's work well all around for a 2 driver car. The DTC 70's stop awesome but the 10's are a bit lighter on the wallet. I would look at the temp range on the pads if you are going to track it. I,personally,like 1200*+ operating range on the pads. You also have to remember that some of these brakes are going to need some heat so you can't go bad @ss into the first corner and expect them to work @ 100%. The lower temp pads work good at autocrosses and often have a lower operating temp and work well when they are cold. I have heard a few people that actually prefer the HPS or HP+ for low speed events over the HT and DTC series. Makes good sense.

Again I think the GS brakes have been very effective and durable as well.

Perhaps the most important element is going to be driving style. Driving @ 100% for 20 minutes will burn em' up quick. If you feel fade, back out for awhile and let em' cool down. Driving smart goes a long way toward part(s) longevity.

froggy47

I am not a track day expert, but have done quite a bit of ax.

Having said that, if you are just going out a few times a year & keep good fluid & correct pad choice you'll be fine with the GS calipers.

If you are tracking the car a couple of times a month and are going 10/10's I'd pass on the GS calipers.

All depends on what you want to do with the car.

froggy47

Wrong pad.

Gearheadotaku

I've heard of caliper spread, was hopeing new ones wouls last longer than this...
I ran the 12" set up for several track days over the years, they overheated several times and I used up pads, but never like this. Guess I'm driving harder? I've autocrossed for 10 years is various cars, now the track-day bug is really chewing on me....$$$$$$

Z06_BluByU

Thanks.. this will be my first tack event.. So i'm guessing more like 5/10's max.. I'm supposing this two day event is gonna kill my brand new tires as well isnt it..