rchaas

I run GiroDisc rotors and DS2500 pads on my 991.2 C2S. I have an upcoming PCA DE weekend. My front pads are at 6mm (slightly under at 5.9) and rears at closer to 7mm. I have done a brake flush. I have replacement rotors/pads for later this year but now I'm wondering if I should just replace them now. Are those thicknesses good enough? Does wear accelerate as the pads thin?

Thanks for your thoughts.

Frank 993 C4S

If you are running with a PCA region, most require 50% pad thickness at the tech inspection. I find it good practice to replace pads for track driving when you have hit 50% thickness. It really helps with reducing the heat transfer to the brake fluid. You can always run the 50% pads on the street again later.

ProCoach

Temps, thus wear, increase as the friction material is thinner. The point of better heat insulation from the rotors to the pistons is very good, too. Depending on the thermal load and braking requirements of the track you’re going to, might be best to change them.

ldamelio

+1. Wear does indeed accelerate as pads thin. Anecdotally, I notice this especially with the DS2500. Half width does not mean half life for track use. In very general terms, it's 50/50 that yours would make it through a weekend - much depends on the track and your driving. You're probably fine for one day; questionable for two. As stated, these have many thousands of street miles left in them - start fresh and keep these in your box to use as spares for late in a track weekend or for off season street use.

zedcat

Presume you are measuring the friction material excluding the backing plate? Most street porsches run pads with 10 to 12 mm of friction material when new, so you are probably at about 50-60% on the fronts, which some tech forms state as the minimum to start an event. Have you checked inside and outside pads both leading and trailing edge, checking for tapered wear? Do you monitor the wear after every event, and know how many events you have done to reach the current wear? As others have said wear tends to accelerate as the pads get thinner and you will get more heat into the calipers/ fluid. You may be ok for one more event. That said, if you have a doubt, best to change them out.

Zhao

I'd 100% run them myself, but you must inspect them frequently and should have backup pads and rotors ready to go in the truck/trailer. Pads rarely wear even. Inside vs outside are often quite different. Corners also wear different. 6mm in one spot could be 3mm somewhere else.

Agreed on 2 days is hit or miss for the fronts depending on the track and how much you're actually on track.

rchaas

New DS2500 are 11.4 mm, so very close to 50% by measure alone on the fronts. Yes, I am excluding the backing plate and I haven't seen any significant taper. Inner and outer thicknesses are similar. There are two days and I'll drive in most but not all of the sessions. Its at Hallett, a technical track with lots of braking. The current set have six DE days and two seasons of autocross and some round town driving as well. I won't be setup for brake work during the weekend should they reach end of life, so I think its best to just change them out. I have all the bits and was planning soon after this weekend anyhow.

Appreciate all the great input, thanks!

Kitc2246

After having to drive home after two days of a three day event to put on the new pads I left at home, now I always carry a set that would pass tech for at least one day or new pads. No need to bring a jack, there will be plenty at the track.

lgusto

My reply is a bit philosophical, but as a professional mariner I've learned that the time to put on a life jacket is when you first start asking yourself when it might be time to put on a life jacket.

JRitt@essex

A good rule of thumb is that you should seriously consider replacing the pads when the thickness of the pad material itself is equal to or less than the thickness of the backing plate. So if you're inspecting your pads and find that the pad puck material is thinner than the backing plate, you should be prepared to change them.

Also very important...make sure you inspect both your inner and outer pads at each corner of the car. Many people just glance through the wheel spokes, but don't look at the pads on the inner half of the caliper. Pad wear is uneven more often than it is even. As such, your inside pad may be considerably thinner than the outer one.

As noted above, pads do burn more quickly as they get thinner...wear accelerates.

Please see our Essex Track and Racing Pad Owner's Guide for lots of other tips and tricks about how to get the most out of your brake pads.

steveP911

Agree with the comments above, but I would suggest you consider a different pad if you are doing much DE track time. I also believed the DS2500's "it's a street and a track pad" claim. Used them for one 2-day event and they faded on later session hard braking. Managed to sell them (via RL) and replaced with Ferodo DS3.12's. I really like them, and they do seem to be long wearing. Yes, they squeak on the street but it doesn't bother me. Maybe others can recommend a track pad with less squeak if that matters to you. Me, I am all in for brakes that work on the track...

Good luck!

JRitt@essex

Thank you for supporting Ferodo pads, and I'm glad you found the compound that works for you. Some experimentation is typically required to figure out which is the best option to meet your specific needs.

The Ferodo DS2500 is a great race pad for lightweight cars like a Miata or BRZ, but is more suited for sport use, rather than track use, for most people running a 911. Some owners can get away with tracking the DS2500, but that would typically fall under one or more of these conditions:
1. The track being run is easy on brakes. That means a more meandering track with lots of turns, rather than a track with long straights followed by tight turns (in other words, NOT Watkins Glen, Road America, Sebring, Laguna Seca, COTA, etc.)
2. The vehicle has a high-quality aftermarket big brake kit installed (AP Racing Radi-CAL, etc.)...this significantly lowers the brake operating temps vs. OEM discs and calipers, which may allow milder pads to survive .
3. The car is on street tires...the overall braking capacity of the vehicle is lowered due to having less grip to leverage on the track surface.
3. The driver tends to be easy on their brakes

The DS2500 has lower max operating temperature, fade resistance, and durability vs. the other pure racing compounds from Ferodo (DS3.12, DS1.11, DSUNO, and DS3000).

For more insights on choosing the correct Ferodo compound, please see our article, "Which Ferodo Racing Pad Compound is Right for Me?" on the Essex Blog.

jgiannone

Just a different perspective, adding to what's been said by others. If we go to the track with a car worth $100,00, with our health in mind, and with at least $1500-$2000 already spent on the weekend, don't try to salvage the last $300 worth of brake pads. You end up with compromised braking, having to swap pads during the event, or an incident. One step further, if you want to end the weekend at 50% of pad life, you likely have to start at 100%.

rchaas

I’ve been happy with ds2500. Hallett is technical but only two straightaways, neither terribly long. Also, I have girodisc rotors which may help some, and I’m on cup2’s or similar, not R compound or slicks. And finally, although I drive hard when on track, I’m only at 3-4 track days per season, so the first set of pads lasted a couple years. So, I ordered another set of ds2500. That said, it’s be interesting to put a set of racing pads on and try them!

ANGST

I ran DS2500s on my Cayman , just switched to 3.12 , and so far been very happy after 2 days on NJMP Lightning. We will see if they wear slower than the 2500s . I plan on switching back to 2500 for the street .

To reiterate what @JRitt@essex says , check the inside pads . My outsides were maybe 6mm , but the inside was 2-3mm after a few track days.