2fcknfst

My understanding of brake squeal was that the groves in the disc did not necessarily line up with the groves on the pad and this, in some circumstances, could create high frequency vibrations as the rotor turned due to the irregular surface on both the pad and the disk - 'squeal' as it were - which was the pad pad vibrating seriously within its carrier. This situation is exaggerated if you use a caliper without dust shields, centring pucks - like some of the rally calipers available from AP. This is where I first experienced this; got the caliper for a good price, but until I slathered the back of the pad with automotive goo, they squealed to high hell, super irritating.

I see similar behaviour on the 991/M5, especially when the disks are cold - now both of those cars are using factory pads, so nothing too fancy, but on partial braking, they make a lot of noise.

993GT

+996, would love to run my PFC's everyday but the squeal is next level broken dump truck bad on street lol

pfbz

Even on track pads? I usually do the same, and on street pads, it can kill the squeal... But on these track pads, i think they just don't get the heat in them to work properly unless on the track. But they sure do work nicely when you throw the anchor out at the end of a straight!

----

Just read John's reply... yes, nature of the beast. Fortunately the 996 Turbos still have fast-swap calipers.

pfbz

Exactly! Lovely in local traffic...


I had tried using the PFC's to combat my brake judder once before and it didn't work as well... I think it was largely because I didn't get the new pads bedded sufficiently Kind of dangerous/obnoxious to do repeated 60 mph -> 10 mph threshold braking stops on an open track day. But yesterday I was on a private track rental and able to do repeated high threshold stops and then a full lap with zero braking to cool down, did the trick!

sabba

I try and find an off the beaten path location, and odd time of the day and perform the bedding procedure on the road. Keep a keen awareness of surroundings , especially rear view mirror and go at it. Then enjoy the game of not using brakes on the cool off drive back home-easier said then done. I ran a full PFC setup on a S54 bmw and it was amazing stuff on track… ran 08’s on track and their Z rated street pads off track to mitigate the Noise.

2jzhx60

Took the car out in the sun first time after the winter after installing the GT2 front end and wing. Still needs a little work to get it on the road:



Installed some Techart intercooler guides / slats




Also installed an extension for the steering wheel:

docwyte

There's that stretch on county line between s holly and colorado that I've bedded pads on before, Now that they've added that light at the bottom I may not be able to go there anymore. I've driven to eat quincy off e470 before too....

2fcknfst

I have never used those pads, only a Hawk track pad and the R4, then moved to the R4S on steel rotors, and never looked back.

The R4S can still make some noise, and don't work great in sub zero Temps until they are warm.

I haven't been on a track in a long, long time, but that level of squealing would drive me nuts.

2fcknfst

Those wheels are pretty slick.

Capt. Obvious

Those are Gemballa wheels if I recall correctly. Fairly rare.

@2jzhx60 that's an interesting interior color combo in your car. Is it factory?

2fcknfst

A good looking wheel for sure.

Took the right front wheel off to investigate the mystery goo... the boot was in good shape and no evidence off tears or rips, so happy on that front.

However, when I wiggled the shock, there appeared to be a little play in it - this seemed to coincide with a new clunk sound, so I am wondering, is that the shock tower bearing? Everything else seemed to be pretty sound and the clunk seems to only present itself occasionally, over a rough bit of road, only right front.

Is there something else I can do to verify this?

lost27

Not sure if this will help you but this sounds like my clunk that I was getting. It ended up being the top hats for the coilovers: https://rennlist.com/forums/996-turb...l#post17988511

2fcknfst

Interesting - I will look into that, thank you.

@911rod if memory serves, you recently rebuilt your PSS9 coil overs, are the top hats factory units that are compatible with the coil overs, or did you use another part?

Cheers,

2jzhx60

Yeah they are Gemballa wheels. I bought them from Germany last year.

I took them apart during the winter and painted the centers gun metal:





The interior is factory, it's code 99 customer sample. So it's ordered custom white like that.

Here's another pic of the interior:

lost27

I had my PSS9 top hats replaced with OEM units.