Not sure if this will go away after being worked in awhile, but the brakes squeal at pretty much every stop from 15kph down to 0. My 911 used to do this too, but only after I went to these race pads on it.

Is this just the nature of the beast, or are the brakes not worn in/seated properly?

 

From what I've read in the GT3 section, it's the nature of the beast since the stock pads are very aggressive. Bedding them in might get rid of it temporarily, but unless you continue to drive it hard, the aggressive stock pads will scrape their deposits off the rotors rather than continuing to lay down more transfer layer, at which point the squealing will return. For what it's worth, PFC 11 and Ferodo DS1.11 have both been suggested as very capable track pads with minimal squeal, but I bet even they would wouldn't be completely quiet under all conditions on the road. When I have my PFC 08s in my M3, the squeal only occurs in that speed range under moderate braking, so if I see pedestrians nearby I'll brake harder or lighter to try to eliminate the squeal out of sympathy for their eardrums.

 

Nature of the beast for a GT car!

 

It's caused by vibration, which is caused by friction. Generally higher friction pads are going to make noise. Some pads come with a vibration absourbing backing on the pad to help reduce noise. The noise can get worse as the pads wear down because there is less mass to dampen the noise. Whatever you do, do not use the gunk some people use to fuse the pads onto the pistons - I've had that stuff (installed as routine by dealer) catch on fire and destroy the dust boots on a BMW.

 

need to bed new brakes....
always bed them then use them hard. squealing will go away (with proper use)

 

Oem pads are known to dust and make noise
Pfc11 dust less and make less noise than oem (almost none)
Ds1.11 are a great track pad but make more noise than oem and PFC

 

Bummer, I was just reading that the DS1.11 are a great enduro pad, which suggested that they'd be a good replacement for the 08s I'm currently using, but not if they're going to be noisy on the road. Ordinarily I wouldn't care since I currently swap between street and track pads, but given that this car's street pads are already track pads, I don't see myself doing that, so I'd want something capable on track and as civilized as can reasonably be expected on the road. Sounds like PFC 11 is my animal.

Any impressions of how the PFC 11s and DS1.11 compare in terms of pad life and rotor friendliness?

 

So is there a downside to swithcing to Pfc11?

TIA

 

The DS1.11 pads will last longer than PFC. I haven't noticed a difference in rotor wear. The DS1.11 has a firmer pedal and shorter travel than PFC11. It requires less pedal effort for maximum braking, which makes it easier to modulate.

From OEM? IMO, I don't think so. PFC11 will last longer, dust less, and make less noise.

 

Thanks! But I'd have thought that longer pedal travel would make braking easier to modulate since you have more range for adjustment, similar to a linear throttle vs a very punchy one. What am I missing here?

 

ALL pads designed for race use will mechanically wear the discs at cold temperatures (street use) because they are designed to operate at temperatures only seen on the racetrack. When pads mechanically wear the discs instead of operating at the right temp range, squealing is the result. Rotor wear and noise is the tradeoff for running a race pad on the street.

They all do it, just some are less than others. Some chamfering and shims may lessen the noise on a race pad.

Street pads are designed to be quiet and work under cold temperatures without destroying the rotors.

 

Do you have any street pad recommendations that fit this caliper? I'd actually consider running one given that my car will see a fair amount of off-track usage. Then again, the removal of the quick pad swap bridge on the front calipers for the 991/981 makes that a more aggravating proposition. Either way, I will definitely be getting a stud and nut kit so I don't have to deal with the one-time use bolts and accelerated wear on the upright threads, though.

 

Youtube 'burnishing brakes' etc. The whole routine of taking the car from 60mph down to 5mph over and over again definitely made a difference for me.

 

You're not missing anything. It's all personal preference.

 

Yes. A good pad for you would be a TS20 or a RE10. The TS20 is a race inspired street compound that works well on tracks as well.
The RE10 is a racing compound but can also be used on the street.
Depending on how much you track the car we can find the best option for you