TR6

I have a couple of DE's coming up and just pulled my brake pads to check the thickness. I'd like to get some input on this. I am running PFC97 pads both front and rear on a 964 C2 (RSA). On the late 964's like mine, the brakes are identical front and rear. New pad thickness is about 11.25mm. My rears are between 3.5mm to 5mm (it varies between the pads). By my calculations, my rear pads are about 1/3 of original thickness. Are these too thin to run on the rear for track days? I run in the intermediate run group (yellow). My front pads are 7.3mm (65% of original thickness), so no issues there. I have a new set of pads in the box as back ups, but don't want to throw out the rears if they still have a couple of track days left in them. No sense wasting money if I don't have to. When I do replace the rears, I'll rotate the used fronts to the rear and put the brand new pads in the front.

Veloce Raptor

The good thing about PFC race pads like the 97's and 01's is that they are unique: you can run them down to the backing plate, especially in cooler weather. The bad news with 67% wear in the rear of a 911 (which will consume rear pads generally faster than fronts, IIRC), when contemplating a braking track like MSR with any pad, is that you may find yourself down to said backing plate before the weekend is over. So IMO run then Saturday, then check to see if you need ot replace them before Sunday.

Also, since the rears wear faster, why not leave the fronts alone when you do replace the rears? they may wear out at the same rate.

tkerrmd

I dont like to run them all the way down even if they can still brake because of the fact that the thinner pad transmits heat more readily. I never go to the track for a weekend starting out at less than 50% without plans to do one pad change.
I use pagid yellows R29 front, black rear.

Veloce Raptor

Again, Pagids CANNOT be run down that far safely. PFC's can, and may be unique in this.

Todsimpson

My experience with 964 brakes on an early 911 was that the fronts wear about 2X as fast as the rear. (While the pad size is the same F+R the front pistons are much larger.)

Were these pads all new when replaced? So you are wearing the rear much faster? Or have the fronts been replaced at some point?

Gary R.

As VR said, get a set of rears to bring and take a look after day 1. You should be fine.

Chris M.

Check your tech inspection form as some regions I've run with require at least 50% pad life remaining.

I run the 97s too and after 7 events I'm still above 50% so I would feel comfortable running them with 1/3 thickness.

PedroNole

+1

Rear TIRES wear faster in a 911 but the front brake pads (in a stock setup...no adjustable bias control) will wear about twice as fast.

I change my pads when the pad thickness is even or less than the backing plate.

TR6

This is my experience also. Fronts wear faster than the rears. Not sure it has anything to do with piston size though. I think it is just weight transfer to the front while braking puts a lot more work load on the fronts. The rears that are there now were previously up front earlier this year and when they got down to 50%, I put new pads in the front and moved the old front pads to the rear.

The decision I have is whether to go ahead and make that swap now and put new pads in and toss the rear pads that have 1/3 remaining, or run it at least on Day One the way it is and then check them. Again, I have a new set of pads with me so I can easily swap them out at the track if needed (easily being a relative term). Based on everyone's input, I think I'll go ahead and run them they way they are and check them at end of day one. This is for MSR Cresson next weekend. I'll definitely have new pads swapped in for Eagles Canyon. That track is much harder on brakes!

I appreciate the feedback everyone!

deep_uv

In a 964 C2 with the same calipers front and rear, like Gregs, the fronts wear at least 2x faster than the rears.

Bull

I have lost track of how many 911s I have tracked in the past 35+ years, both racing and DE, and I have never had a 911 wear the rear pads more quickly than the fronts...or even as quickly as the fronts. In some 911s, I have had the rears wear only slightly less than the fronts, but those were rare. My current RSA, with stock brakes (same pads front and rear, different pistons) wears the front much more quickly than the rears.

Anyway, if my pads are more than 50% worn prior to an event, I usually replace them before the event (exception might be a 2 day event at a track that is relatively easy on my brakes). While I always have back-ups, I'm am VERY lazy and would rather be enjoying a cold one or three after a track day than changing brake pads.

ltc

IIRC, there is a company that manufactures titanium based 'shims' that mount betwee the brake pad backing and the piston, designed to minimize heat trasfer to the fluid.
I have not tried nor bought them, nor tried to work out the math/thermodyanics to see if their claim is reasonable.

Veloce Raptor

Interesting. I stand corrected. A bunch of guys I know with 996 GT3's get rear wear that is faster than front. I assumed it was common across other 911 series as well.

TR6

LMAO!

deep_uv

+1

My experience and laziness as well . And as you point out, I should've said same pads, not calipers. There's a bias valve involved in this discussion as well.