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PCF08 - Squealing on Track

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Old 05-23-2016, 12:10 PM
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3Series
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Default PCF08 - Squealing on Track

Guys,
This is my first season running with race pads. Car is a 997.2.

I just finished my second track day running with PFC08's front and rear and both days (a week apart) were sunny and 70-80 degrees, DE events.

So my question is, do PFC08's squeal for anyone else when being applied on track? I would think they have enough heat in them with repeated 100-50mph stops after the firs session.

There was a black flag and when I pulled to the pits, besides the starter telling me what was going on the track, he mentioned I should check my pads because they were squealing loudly and he thought they might be running low.

Or do I need to adjust my braking?
Old 05-23-2016, 12:22 PM
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Drew_K
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I've never had track pads squeal once they're up to temperature, including PFC08's. Sounds like you need to pull the wheels and take a closer look. Also, don't just look at the outside pads with the wheels on and assume the inner pad is the same thickness. I've seen rotors stick where the outside pad looked fine but the inner pad was worn down.
Old 05-23-2016, 12:38 PM
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Originally Posted by Drew_K
I've never had track pads squeal once they're up to temperature, including PFC08's. Sounds like you need to pull the wheels and take a closer look. Also, don't just look at the outside pads with the wheels on and assume the inner pad is the same thickness. I've seen rotors stick where the outside pad looked fine but the inner pad was worn down.

That's what the starter said at the grid, I haven't looked yet, but the pads are essentially new (on the outside at least).

Everything seems fine, the car stops, and I tested different braking marker spots with not a big difference in sound.
Old 05-23-2016, 12:42 PM
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Frank 993 C4S
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They should not squeal bedded correctly. Did you bed them?

Bedding Brakes
Old 05-23-2016, 01:09 PM
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Originally Posted by Frank 993 C4S
They should not squeal bedded correctly. Did you bed them?

Bedding Brakes

Nope. I thought the PFC08's didn't have to be bedded. I put them in with brand new Sebro Coasted rotors.

I drove maybe 100 miles of regular city/highway street driving. Then drove 100 miles highway and tracked them for a day.

Then drove maybe 40 miles city/highway during the week, drove 40 miles highway to a track day on Saturday and they still squealed after session 5 (25min session) braking from 110 to 50 or so.

Maybe i'm braking incorrectly? I'm braking straight, getting my braking done before turning in...
Old 05-23-2016, 01:46 PM
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My PFC08s on my 997.2 squealed ALL the time on track. In my experience, PFC08s start to squeal more once they are bedded in.

The issue I have had with PFC08s on two different cars is that they will "chatter" when not properly bedded in on a rotor that has been used with different pads. Once the pad is properly bedded in, it is great. The pads will start to really squeal at that point.
Old 05-23-2016, 02:12 PM
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If you push the pedal harder, they'll squeal less. Seriously, the squeal is a high frequency vibration enhanced by any clearance between the piston, pad backing plate, friction surface, rotor and mounting ears. Without freshly resurfaced (or new, if specified) rotors and scrupulously clean components, it's hard to completely eliminate this.
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Old 05-23-2016, 03:37 PM
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Frank 993 C4S
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Originally Posted by 3Series
Nope. I thought the PFC08's didn't have to be bedded. I put them in with brand new Sebro Coasted rotors.
Click on the link I provided above. It explains the physics and the procedure. Race Pads will ALWAYS squeal if your are too light on the brakes (like street driving).
Old 05-23-2016, 04:04 PM
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The truth is 08 always scream. I love screamers !!
Old 05-23-2016, 06:01 PM
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Originally Posted by ProCoach
Seriously, the squeal is a high frequency vibration enhanced by any clearance between the piston, pad backing plate, friction surface, rotor and mounting ears. Without freshly resurfaced (or new, if specified) rotors and scrupulously clean components, it's hard to completely eliminate this.
I use those pads and had furious squealing - track and street (my son wouldn't ride in that car anymore)! Then I changed front rotors to new, slotted... and magic!! NO more squealing...street or track!!
Old 05-23-2016, 06:14 PM
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Originally Posted by johneecatt
I use those pads and had furious squealing - track and street (my son wouldn't ride in that car anymore)! Then I changed front rotors to new, slotted... and magic!! NO more squealing...street or track!!
Good to know. I like slotted rotors for surface gas-off dissipation.
Old 05-23-2016, 08:01 PM
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I use 08s and 11s with slotted rotors. No noise
Old 05-23-2016, 08:27 PM
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totally quiet on track, VERY loud on street
08 front/ 11 rear
Old 05-25-2016, 12:02 PM
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Originally Posted by johneecatt
I use those pads and had furious squealing - track and street (my son wouldn't ride in that car anymore)! Then I changed front rotors to new, slotted... and magic!! NO more squealing...street or track!!

Hmm, maybe its brake residue in the rotor holes that's reacting with the pad and squealing.

All 4 rotors are new (2 track days on them) so I'm not replacing right now.
Old 05-25-2016, 12:20 PM
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I just put in pfc08's with new ATE Cayenne rotors, bedded them in with a few 100mph>40mph runs, and now they squeal to ear-pain on the street. Haven't done track with them yet. Previously had Pagid Yellows with the same rotors and had zero noise both on street and track. Would it help to apply some anti-squeal brake paste on the back of the pads? Anyone done this?


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