Minimum HPDE Brake Pad Thickness
 

Does anyone know what the minimum recommended brake pad thickness is for a two-day HPDE? I pulled the front right brake pads on my car today:

https://farm4.staticflickr.com/3946/...df157140_o.jpg

It ranged from 4/32 - 6/32" (3.2mm - 4.8mm) -- left to right in that shot.

Here is the other pad:

https://farm4.staticflickr.com/3941/...4a9fabd5_o.jpg

The only recommendation I could find was 5/32" for a single track day, so I assume I should replace these before my next track weekend, but just wanted to make sure.

And a few other pics I took, in case anyone sees any problems:

https://farm4.staticflickr.com/3941/...c86823a2_o.jpg

https://farm4.staticflickr.com/3933/...75b3e54a_o.jpg

Small chunk missing here:

https://farm6.staticflickr.com/5611/...e2ff0877_o.jpg

Shot of the rotor:

https://farm4.staticflickr.com/3937/...642987cf_b.jpg

Thanks!

I would definitely get new pads before a two day event, most schools suggest at least 50% of original thickness as a guideline.

What pads are those? I would suggest something that takes heat better, those look like they've been overheated and melted.

Probably best to state the compound along with all of your braking components, and then ask for input from other drivers running that same compound under similar circumstances.

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It's all about the compound, how it tends to wear down, and the sort of braking demands the track and driver are placing upon the ducted/un-ducted brake system. Remember that one major purpose of the pad is to act as a heat sink, so somewhat thin pads like yours demand a top-quality fluid if the driver is using the braking system hard, and it looks like that's the case here.

Based upon the depth you currently have, I think you'd want to have a spare set to throw on in case those pads prove insufficient for the length of the event. The existing chunking is relatively minor. The lower section of the rotor indicates that you may have some pad smear in that region (indicating you've overheated the pad), but I'm not 100% sure that's what it is.

FWIW, and this is definitely in do-not-try-this-at-home territory, I've run one manufacturer's pad down to super-thin thickness and still had sufficient braking effect to continue with the DE. Some compounds don't tolerate thin pads very well - they just give up.

No way I'd go to the track with those. Time for some new pads.

Thanks guys. I ordered another set of front pads to be safe.

BTW these are Stoptech SP pads. Brakes are otherwise stock. Held up better than expected, but I'll probably go with Carbotech XP8 or XP10 next.

Definitely new pads for a two day event. I would also go with new rotors, especially if you change to Carbotech pads. You may be able to use inexpensive rotors like Centric Plain 120 series rotors. I have had good luck with these.

Yah, those look thin. One problem with thin pads is that you conduct more heat into the caliper. Less insulation there. Some pads wear longer though, like the PFC 08 :)

I'd change those. I have some Project Mu Club Racers front and back that were only used for one event. They have over 90% pad left. Don't need them anymore because I sold the car.

Definitely need to step up the pads. They're being overheated and smeared onto your rotor.

Are you still using the OEM fluid? If so, I highly recommend upgrading to Torque RT700.

I was actually thinking the same thing. Will probably do a full rotor swap this winter to new Centric blanks. Thanks for the recommendation.

Yeah I could see some smearing on the front left rotor as well when I pulled that wheel. I'm thinking about Carbotech (or Winmax, which I think you had good experience with) next. Haha you'll probably see a PM from me in a few months asking for a recommendation. ;)

Thanks I was on Stoptech STR600 fluid and actually downgraded to ATE Type 200 (i.e., Superblue) this past season. I haven't had any issues with brake fluid boiling yet with this car. I'll keep the RT700 in mind though if I start running into issues.

I would definitely replace those pads, even if I wasn't going to an HPDE. Also something I like to do even if I am not changing brand or compound is to take the rotors off and clean them up really good with brake cleaner, just to try and get the old bedding off the rotor.

Just my 2c.