[Jazzbass]

Two brake questions:

1. I was looking at my track pads last night when regreasing the front wheel bearings. They are Kool Karbons from Pete Tremper and have 9 track days on them. They have half the pad left on them - time for a change?

I have another new set of pads, so could swap the new ones in tonight to be ready for this weekend. I was just wondering what threshold others used for swapping pads... 3/4? 1/2? 1/4? 5/16?

2. How is SC on brakes? Its a slower track, so I imagine you wouldn't have the heavy braking zones like into 1 and 5 at SP, but there are so many turns it seems like you'd be on the brakes a lot. How does it compare to SP WRT brake?

If it matters: 85 911 Carrera, about 2800 lbs, stock calipers, 993 cooling scoops on the front.

[Eli]

After doing grid tech a couple of times, I was told to make sure the pads were equivalent to the backing plate. If less, it's time to swap....

[APKhaos]

Chris,
It depends. Beyond 50% wear, the pads still retain their original friction charateristcs, but are degraded in their ability to dissipate heat. If you are not experiencing fade/pedal softness, you could leave them in until that starts.

Changing pads at around 50% is typical racer behavior, because its a given that fade/pedal softness will turn up in the middle fo a life or death dice. No such pressure situations in DE, right???

[MatP]

SC was easier on brakes than main course for me. Others may have a different opinion.

Since you have 9 track days and still have half the pad, you will be fine. For Tech inspection, we compare the amount of pad with the thickness of the pad backing plate. If the thicknesses are about the same, we caution the owner and recommend that they keep an eye on pad wear and bring a spare set for Sunday. If there is less pad than backing plate, its time for new pads.

-- just noticed Eli's post. Beat me to it. --

[TD in DC]

Originally Posted by MatP

SC was easier on brakes than main course for me. Others may have a different opinion.

I agree. There are fewer brake zones than you would imagine, and even where you might tap them it is more for weight management than for serious braking. Really not that bad. I was playing a game on the track trying to tell myself that I didn't have any brakes at all. You would be amazed at what you can do with just some well placed lifts.

[Trak Ratt]

I believe pads wear faster as they get thinner because of the “heat” as Tony said. Put the new ones in, dust off the others and keep them in your track box as “spares”. You’re be glade you did this weekend and gladder still if you burn through some later and just happen to have a serviceable set as backup. Many Dorki have benefited from this strategy in the past.

[MBuck951]

I do not agree with the idea of removing pads “prematurely” only to save them as spares. If the pad is good enough to keep as a spare, it is good enough to remain on the car. When performance begins to suffer (any driver should be able to feel this) swap in new pads and throw the others away. With my car, I do not notice a significant decrease in performance until the pad is way less than 50% remaining. Even then, its not like “OMG, I have no brakes!” I check my pads between each session and change as necessary. With any Porsche I’ve seen, it is an easy job.

The only exception to this (for DE anyway) is if you do not want to bother with changing pads at the track. Therefore, if that pads are approaching 40-50% and you don’t think they’ll last the weekend and don’t want to be working on the car at the track, swap them out for new at home. Throw the worn ones away.

Also change the pads if the car won’t pass tech, regardless of whether you feel it is warranted.

It helps to find a particular brand of pad you like and stick with it. That way you gather data about its wear characteristics and can adjust your supplies as needed. I use PF 97's. Recently I set out for a 6 DE day trip to Canada. The pads in my car had 4 events on them. I didn't think twice about bringing another set of pads because I knew they would last. Short of some catastrophic failure, I would not need new pads. If such failure had occured, I probably shouldn't be driving the car anyway!!

my .02

[}{arlequin]

I'd keep using them but bring spares to the track. I like to milk every part of my car to its fullest. As others stated, you'll know when your brakes are getting too hot/mushy b/c they are too thin.

SC is not hard on the brakes.

[racer]

Keep the current ones in and bring the extra set with you. Check them later in the afternoon. If its time for a change, you'll have the extras and be back on course. All the tech forms usually say is that you need 50% at the start of the event (typically 50% is equal to the backing plate thickness).

[Vicegrip]

Agree with keep the ones you have in and bring extra to track. Pads will wear faster as they get thinner but you just need to watch them and be ready to replace when they get too thin or the heat starts to get through. Keep an eye on inner pads as well. Some cars use up the inners faster than the outers. Most times this is seen on single piston binder cars.

There are a bunch of S.C. brake zones! More but not as hard as say the front straight at Summit or VIR

S = small. M = medium. B=big.
1 Before cave esses-S.
2 Before hook-M.
3 At #8-M.
4 At the Karosel-B.
5 At the hard right going over the hill S.
6 At the end of the back straight-B.
7 At the L/R set going into the pit straight-M
8 At end of the pit straight-S.

I was taking temps and I get much more heat at the SC than at Summit main track.