Brake failure at the race track
 

Hi,

My '13 GT86 is almost fully stock, with only minor changes:
- Oz Alleggerita HLT 18" rims
- Michelin SuperSport 225/40 tires (36/34psi front/back - hot)
- EBC yellowstuff pads all-around (stock rotors, calipers and brake-lines)
- Castrol SRF Racing DOT4 brake fluid

The pads and fluid have been used for 4-5 sessions in total (20 min each) since changed/new.

At my last trackday (with 2h cooldown after the first session) I lost brakes completely after 8-10 minutes of really pushing the car to the limits, on a hot 31C outside temperature (the car was reading 41C!). There are 2 consecutive high speed braking corners, in the first one from I braked from 180km/h to about 90 and in the second one (10-15 seconds later) from 170 to about 60 - this is where I lost the brakes. I pressed the pedal multiple times with almost no effect. I switched to 3rd gear to slow down and reached the grass at ~100km. I stopped in about 70 meters after reaching the grass (fortunately the track fence was at about 100m, so apparent damage).

The strange thing is that after returning to the track the brakes worked just fine. Obviously I did not pushed them as hard again.

I never observed any issues in my previous trackdays (first 2 with stock pads and fluid) since I got the car (6 months ago), but this was the hottest day so far.

I'm thinking that maybe the brakes were overheating, but Yellowstuff pads have very high temperature rating and the same goes for the Castrol SRF.

What do you guys think?

Those pads are pretty trash. I once cooked over yellow's on my buddy's civic on the street coming off the highway. Definitely find something more capable.

Since am going to change the rotors as well, I'm thinking StopTech for both rotors and pads. I'm also looking at Hawk's HP+ kit.

The question is, changing the rotors/pads will solve the problem? I'm not even sure what the problem was...

I would check for rotor thickness and if they're bad go for a new oem or centric blanks. No need for slotted or drilled rotors.

HP+ may or may not do the trick, it'll be hard to tell without knowing what track you're running and how hard it is on brakes.

It was definitely your pads being pushed outside their effective heat range. (fade)

Was the pedal still hard and just no bite from the pads, or was the pedal soft and going to the floor? If the pedal was hard but no bite you simply overheated the pads. I'll bet there was some serious smearing on the rotors and the pads will be glazed too. Have you pulled the pads to see what they look like? I'll bet quite worn down in addition to the smearing/glazing.

Yellowstuffs aren't really that fantastic compared to real race pads, there's definitely better options out there for you. I would run far away from stoptech pads or HP+ if you're overheating these. Look at a proper track pad (project mu club racers, gloc R10 or higher, csg spec pads, winmax w6 or w7, etc).

Centric blanks are a great rotor, no need to spend more money unless you're going to a BBK.

yellowstuff arent track pads, theyre a hybrid similar to HP+, id suggest moving to something like Hawk DTC60.

The pedal was no softer/harder than usual. Just no bite. Also I did not observed any smearing but I'll take the pads off anyway to make sure they are ok (before the next trackday).

Worth noting: I painted the calipers using K2 spray paint and it was completely carbonized after just 2 sessions (front only, in the back the paint is intact).

The problem is that I'm using the car as a daily also, so dedicated track pads are not a (convenient) option for me. I'm only going at ~10 trackdays per year but I'm really pushing the limits (I had quite a few "grass encounters" :))

So yellowstuff with their 950C temperature rating seemed like a good compromise :(

Slotted StopTech rotors are just a bit more expensive than Centric (like 50$ for all 4) but I still need to find pads that can be used on the road as well.

Hawk DTC60 I think are track only.

If the pedal feels the same then it is the pad causing the issue. Either get a dedicated set of track pads and live with the noise, or get a set for the road and a set for the track and swap them out as needed. I don't even do as many track days a year as you and I just leave my track pads in all the time as I found swapping annoying.

+1 I've faded yellows at autox, get better pads and bleed the brakes with more srf (likely no need for a full flush). Odds are discs are fine once you've bed in the new pads.

Ferodo DS2500 might be the best hybrid pad you can find but it sounds like you will fade them eventually and have to bite the bullet on swapping pads for events unless you're content backing off for a few laps to cool the brakes.

Good excuse to get a second set of wheels and tires though so you can swap those in for moar laptimes...

You can totally street on DTC-60 and any other race pad as well I bet. You get less life out of them of course, as you basically "unbed" them at the street since they dont get hot enough, but they brake just fine, dont believe magic voodo that race pads dont work when cold, if DTC-60s can brake at freezing temps in Canada, they can work anywhere.

@NoHaveMSG - what racing pads are you using?

@wparsons - looking for project mu club racers I came across project mu HC+ (SKU: PMU-PHF914). Seems to good to be true :)

@strat61caster - I can change the wheels (I kept the original rims) but I can't change the pads myself :(

HC 800+ are a compromise pad, and you'll outgrow them too quick to be worth it.

Pads are easy to change, but I daily drive track pads in the summer (lazy). My favorite pads so far have been the project mu club racers, not a huge fan of the GLoc R10's I currently have.

Those are not HC800+, check by part number please. But yes, still compromise pads :)

If you can swap wheels you can swap pads, it's just two extra bolts per corner and maybe you have to compress the Pistons if the two sets are very different thicknesses.