TGiuliante

Hey Guys - I am planning to purchase Gary's new AP kit for my C6Z06. I have a few questions for those of you that have this kit. Due to the floating rotor design I understand you get some rattling noise coming from the front brakes. Three questions:

1- Exactly why do you get this?
2 - How bad is the noise - enough for you to hear it in the car?
3 - Do you hear this every time on braking?

Any input is appreciated.

Thanks,
Tom

Olitho

I never ever hear any rattling.

Joy of 6

Me neither. where did you get that info?

TGiuliante

I spoke with Gary a while ago and he mentioned that due to the floating rotor the brakes may make some noise - almost like a clicking noise when slowing down at low speeds such as on the street. Perhaps i may have misunderstood him.

From your response the floating caliper does not make any noise?

Olitho

Gary warned me of that possibility, too, but it has never done it for me.

Everett Ogilvie

No noise here. When you first install the system you can wiggle the rotor just a touch due to the full floating design and because the pads aren't out against the rotor with any appreciable force yet. Once properly bled and once you drive the car the pads stay more firmly against the rotor due to the anti knockback springs in the calipers, so no noise.

fatbillybob

Gary is correct in making the warning. You see floaters can and do make noise because of the design and wear patterns of the pads. What happens is people with mostly streetcars copy what the racers do and do not fully understand the compromises. So good for the op to ask. When you are driving with windows up and a/c on and all that sound insulation and street tires you can hear everything. Oli for example has a C5 with no sound insulation, open windows, open exhaust, gutted interior. So the noise of the brakes if any would be a non-issue. Part of the reason many people make 2 piece non-floating rotors is for noise control because streetguys would go bizzerk from the noise. They want the look and to say 2-piece rotor and many will not even know what a floater is. Local vette challenge time trialer even called stoptech to get info on their floating rotor. Stoptech said they only had one rotor the "aero rotor" and that they don't even have a floater. I told my friend to call them back and ask for the Trophy rotor. Then the lightbulbs went on. "oh the rotor for the racers...." So you see even the pros have some issues with this.

davidfarmer

I've never had this noise with Stoptech, RB, or Performance Friction floating rotors. Probably just a warning that you'll likely never hear in reality.

naschmitz

I love the Hardbar AP T1 setup. If you ever have an issue tied to the floating rotors and you want to quiet it down for the street, you can always run the NAPA one-piece rotors with this setup. Might make sense to do that anyways to keep the race pads bedded on the AP rotors and street pads bedded on the NAPA rotors.

argonaut

I have the AP setup. I notice the noise at very low speed like rolling across a parking lot. It's a clicking sound. While driving there is no noise and there is no judder when braking. Both Gary and Jeff Ritter have told me its nothing to worry about. Lately I've taken to swapping to non- floating with street pads and they are dead silent

TGiuliante

Argonaut - that is exactly what I was referring to - Gary mentioned it to me but judging from the responses it seems as though it is not really that bad at all.

So those of you that run Gary's Ap system - how do you like it. have any of you boiled the brakes or got a soft peddle?

Any need to bleed as with the stock caliper after a few 20 min run sessions?

naschmitz

Brakes feel exactly the same after 30 min session as they did at the start. No pad fade either running the CL RC8s or Ferodo DS1.11s. In fact, you have so much pad friction that you need pads with less bite for wet conditions.

Absolutely not. I've done two days worth of 25 min sessions without bleeding the brakes at all with this kit.

TGiuliante

Thanks for the response - How is peddle feel as compared to stock caliper - harder, more feedback?

JRitt@essex

The disc to hat attachment is different on these various systems. These other kits are all street kits. As such, they are intentionally designed with noise abatement features in the mounting system.
StopTech uses something called a belleville washer in their system. It's a little round, conical washer that holds the hat in tension against the disc. It works pretty well and has a good service life. They do tend to flatten out over time though, losing tension. Then they will rattle a bit.
Brembo uses a spring clip. It's just a thin piece of bent metal that accomplishes the same thing as the washer...keeps tension between the hat and disc so they don't rattle around.

The downside to these noise abatement mounting systems is that they do not allow as much float, and are not as effective at combating pad knockback. In racing applications, StopTech actually instructs customers to flip the belleville washers over and run them "upside down" to provide more float in the system. Then they rattle quite a bit. Brembo uses a different mounting system for racing, one that doesn't have a 'spring' built in.

The AP/Hardbar kit is a racing kit designed for maximum performance, so it maximizes the float available for the disc. Low noise/NVH was not a design goal. That said, based on customer feedback the noise seems to be tolerable. We just try to properly set expectations and warn people not to expect a "plush," completely noise-free system as you'd get from OEM or a street system.

JRitt@essex

With any decent aftermarket fixed caliper system you are going to feel a tremendous increase in pedal firmness and modulation. These calipers are particularly stiff, which further enhances that difference.

I removed my aftermarket BBK before I sold my C5Z. When I went back to my old OEM calipers, I almost cried. The pedal felt so sloppy/mushy.

In my opinion, an aftermarket BBK on these cars is a huge improvement in driver input/feel, and provides a big boost in confidence. It's very difficult to go back to OEM sliders after you've run aftermarket fixed calipers on the track.

KNSBrakes

Hey Tom

I can't tell if you mentioned it - but you have a C6Z right? It would be VERY interesting and perhaps revealing to see how this kit compares.

We took a good look at the kit at PRI w/ Gary and Jeff and we can't wait to take a similar approach on the front of an STi. Pretty much every feature is performance related and none are bling.

The rotor floating design is particularly nice - no shear directly on the bolt.

-Ken

TGiuliante

Ken - yes I do have a C6Z. I will let you know once I convert.

davidfarmer

Jeff, good info...... Interesting how no one at Stoptech ever mentioned this to me, seeing how I was one of the first guys racing on Stoptechs??? It makes perfect sense though, more of a system that allows float when thermally necessary, as opposed to being completely free to float all of the time.

fatbillybob

Dave,

You may want to check with ST. Fairly recently ST has made the 2 piece floating "trophy" rotor which is different enough from the street based 2 piece aero rotor that they do not share common parts or so I am told. For the vette ST made a race kit for Lou Gillotti with huge amounts of float in the rotors are Lou's request which use different calipers and different master cylinder must be used. The Trophy rotor is a full floating race rotor and sold only as a race rotor and is on my car now with the first T1 4 caliper kit developed by ST on my car. I was there on the track with ST when they tested and developed the system. Did you buy the street ST system and apply them to the track? If no I wonder how many different ST systems there are out there?

davidfarmer

this was 9 years ago..... I ran their early systems in World Challenge, the Nonamakers ran them in Grand Am Cup. Best I can remember they ran the conical washers Jeff mentioned above. Regardless, they were a great product, and I consider them to still be. As long as the aluminum and steel have enough give to prevent deflection/cracking, I'm satisfied. I never took myself seriously like Lou does......I was competitive, won a race, and had a lot of fun!