I am new to a 12,000 mile GT3, my first "steamer". After putting about 2,000 miles on it I have a question about the brakes that I am not sure is just "the nature of the beast"

My car has 19" wheels with P-Zero Pirelli's. Good tread all around. On firm application of brakes from highway speeds (55-70 mph), dry asphalt or concrete, straight line:

1. It feels like the front brakes momentarily lock up;
2. There is a click sensation in the brake pedal like the ABS is kicking in; and,
3. Sometimes there is a noise from the brakes not unlike old Mercedes ABS systems (1980's)

The rotors are stock steel. The pads have yellow backing and seem to be original. The car was reportedly never tracked and there do not appear to be any strees cracks on the disc face normally associated with track use.

I pulled the front pads and when slliding the face across sandpaper on a flat surface, the contact area appears to be on the ends with the center party of the pad untouched, almost like the pad face was concave.

Normal?

Suggestions?

 

That does not sound normal to me at all. I rarely have ABS kick in and only when the brakes were applied like a "panic stop" (really, really hard). I have not noticed the noises you describe when ABS has kicked in either.

I would have your brake system looked at, best to be sure nothing is wrong with brakes.

I've never run 19" wheels on the car and neither have the other 996 GT3 owners that I know so I'm not sure if that could be a factor or not.

- Jon

 

OEM pads are not typically yellow. Look for lettering or stamping on the backing plate. Pagid, Jurid, Textar?

 

The OEM pads on my 996 GT3 were yellow.

 

Huh? 996 GT3 pads for steel brakes have yellow "ink"/color around the pad compound.

 

The original equipment pads for the 996 GT3 iron disc (6-piston front, 4-piston rear) were Pagid P90 (RS19) and are fully painted yellow.

 

The 996/GT3 calls for 18 inch rims. The larger rims and tires may not have exactly the right profiles. This is probably the case and the ABS is getting confused. There is no PSM on this car, or you would have problems with that as well.

You really need 18 inch rims on this car. The good news is that the tires are cheaper and the car will handle better

 

It seems that the regular 911 and the turbo have options for larger wheels and there is a huge market in aftermarket larger wheels for all of these cars. If the ABS sensor on the wheel assembly detects a lack of rotation while the car is still moving forward the ABS system deduces a skid and activates the ABS. Isn't that correct? How would an 18", 19" or 20" wheel change that? If the wheel stops rotating while the car continues to move, activate ABS.

There have been many suggestions, observations and anecdotal experiences shared here. I am going to check most of the things that were suggested, I just don't understand how wheel size could have such an effect. If there was a significant disparity in traction either because of trie size, tire brand, tire compound, tire condition or front-rear bias, that would seem to me to be relevant.

I just don't know at this point.

 

Pagid RS19's used on the street are boderline dangerous...you simply cannot get enough heat in them for them to work properly. RS19's & 29's are an endurance track compound.

I am always amazed that more guys with 996 GT3 don't use Porterfield R4's.....it's an awesome pad, WAY cheaper than overpriced Pagids (I've used both) and it performs better at lower temps but is much easier on rotors. I run in the advanced groups w/ plenty of GT3's, and they hold up fine at that pace.

You can buy a full set of R4's from places like Livermore Performance for about $410. www.livermoreperformance.com

The 6GT3 is much lighter than my E46 M3, and these pads work great for my car. They can be driven to and from the track, are easy to bed-in, and are not abrasive or caustic in any fashion. Anybody looking for a great pad that doesn't tear up your equipment, give them a try. I plan to use them when I get my GT3.

 

That is what came in my 05 GT3. No problems with them on the street other than some squeel when they are cold.