Toasted Brakes at a Lapping Event - Need Advice

[ddd4114]

Just when I thought I had my brake situation figured out...

For the whole year so far, I have been doing track events using Hawk DTC-60 pads on all four corners, 3" front brake ducts, and OEM non-Brembo calipers and rotors. My pad wear has been reasonable, so I didn't have any concerns. The car is a 2011 Mustang GT with Nitto NT05 tires and basically no other performance upgrades. My peak braking is ~1.1g, and the car weighs ~3770 lb with me in it.

This past weekend, I ran a weekend lapping event at Gingerman Raceway. I didn't think I had any issues the first day until I inspected the car later that night. The left brake pads were almost completely gone, and the right pads only had about 30% material remaining on them. I had arrived at the track with about 60% front and rear pad life remaining. The next morning, I replaced the pads and found that I had also destroyed the boots on my front-left caliper, and I had cracked my rear-left rotor. I had luckily brought replacements for both, so I was able to get the car back on track within an hour or two. The car lasted the rest of the day with only a little fade on the braking zone into turn 5. However, I heard a metal grinding/squealing noise at low speeds coming from one of my wheels as I drove home that evening.

Last night, I took my brakes apart to inspect everything, and I found the following:

Aside from the obvious, I had the following failures:
- Both of the front calipers were toast, including the new one I installed at the track. When I tried to push the pistons back into their bores, they made a crunching noise and then shattered like chalk. No, I'm not exaggerating.
- The slide pin boots were all melted and distorted from the heat.
- All front brake pads were basically converted into paperweights. I guess you could say the one pictured has negative material remaining?
- Many of the rotor surfaces are now noticeably concave. The front rotors have minor cracking, but it's not that bad. I think the only reason they didn't crack was because I installed new ones the previous weekend at Mid-Ohio after cracking both of the previous rotors...

The left-rear brake pads had about 10% material remaining, but the right-rear pads weren't bad. Both rear calipers looked mostly ok.

After seeing the carnage, I have to ask myself: what the hell am I doing wrong?

I definitely need to look into decent backing plates for the pads to retard heat transfer to the calipers. I will also start using DTC-70 pads on the front.

Another concern I have is that I always put the car in sport mode during track events. I'm pretty sure I'll be able to handle the car just fine with everything off, but it's nice to have a backup in case something goes really wrong. Is it possible that, even in sport mode, the stability control is intervening much more than I can detect and is therefore heating the pads? Since the vast majority of the damage occurred on the front brakes, I wouldn't think the effect would be significant. It seems more likely to me that the stock braking system is simply not up to the task.

Since I have to replace the front calipers, rotors, mounting brackets, and pads, I think now is a good time to consider upgrading. American Muscle has a GT500 Brembo conversion kit for ~$1200, which is pretty tempting. However, there is no guarantee that I won't toast these parts too, and they're much more expensive to replace. I'm not sure which route would be easier on the wallet in the long run.

What do you guys think? Any feedback from the track rats on here would be really appreciated. I can post a video of my feeble driving attempts tomorrow evening if that would help.

Thanks,

Dan

 

[stang389]

i have a few questions. first would be how do you use the brake on the track. (trail brake, ride the brakes). secound would be, what speeds are you seeing on the track. 3rd is what fluid are you running (i apologize if i missed it).

 

[ddd4114]

1) I tend to trail brake through a lot of corners, which explains the uneven wear left to right. I try not to hit the ABS so I have some buffer in case of "oh shit" moments. Without going through all of my data, I'm guessing that I typically brake at a little under 1g.

2) My top speed on the back straight at Gingerman was 123 mph. I was hitting ~105 going into turns 1 and 5, and I'm guessing ~95 going into turn 3. At Mid-Ohio and VIR, I'm hitting ~140 mph on the back straights.

3) I'm using ATE Super Blue, and so far, I haven't had any problems with it. My pedal feel remains pretty consistent. I do a quick bleed after every couple track events. I also of course bleed the brakes a little after replacing a caliper.

 

[stang389]

thank you for the answers. do you have a picture of how you have your cooling set up? and where you have it mounted on the front end.

i think one of the issues might be the pad selection with the stock rotor being used. that said. i have used my stock rotors with stock calipers with hawk HP plus pads on all 4 corners running ATE fluid.

another issue might be the weight of the vehicle for the stock brakes. i have my mustang down to 3350 with driver, gas, and autopower rollbar.

i would recommend going to the brembo calipers with a good pad/rotor set up along with a complete flush of the brake fluid. We run motul 600 fluid in my street car/driving event car along with the porsche spec boxster i tech on.

 

[stang389]

also by chance do you have pictures of the rotors?

 

[SoundGuyDave]

Dan,

I feel your pain, brother... I've seen the "seized piston that shatters into a vaguely chalky substance" more times than I can count with the stock fronts, and is pretty much a direct result of overheating the entire braking assembly. The heat (I believe) causes a couple of things to happen, that inter-relate and turn the front brakes into paperweights... First, the bridge of the caliper gets soft, and spreads, causing taper-wear top to bottom, and if it gets bad enough, will cause one or both of the pistons to seize in the caliper bore. At that point, you're effectively dragging the brakes on that side, with the resulting massive heat transfer fatally fatiguing the material the pistons are made of, until they become brittle.

3770 is pretty hefty for an S197 on track, and at that point, ducts may not be enough to keep the stock setup alive. FWIW, before I went to the Brembo fronts, I would get between 12-15 track days out of a set of calipers before I started getting taper wear, and swapped them out. After switching to the Brembo fronts, I got 19 track days on a single set of DTC-60 pads... YMMV, of course, but there is a LOT more pad area, coupled with significantly larger rotors, and the end result is a much larger heat sump. I think you can do better than the $1200 for two calipers and two rotors, though. Forget about the lines, pads, and fluid that comes with the kit, you'll need to run something like Castrol SRF or Motul RBF600 to handle the heat. Based on the 1.1G force you noted, it sounds like you're probably braking properly, so just get the parts you need to make the brakes survive, and see what happens. Oh, and forget about "sport mode," that's still letting the computer manipulate the brakes, and you will see excessive pad wear from it.

 

[ddd4114]

I don't have pictures of the current (concave) rotors, but here is one of the front rotors I cracked at Mid-Ohio:

Clearly some water got on it after I removed it, but that doesn't change much.

 

[ddd4114]

Dave,

It's good to know that Ford is equipping the newer non-Brembo Mustangs with what sounds like a horror show based on what you've described.

I would LOVE to get 12 days out of a single set of DTC-60 front pads. Before Gingerman, I was getting 4-6. Do you think the Brembo calipers would be a good upgrade in the long run for me? Calipers are easy to replace, and if taking replacement ones with me to track events means saving money in the long run, I'm prepared to do that. I just don't want to upgrade and have to pay $300+ to replace a Brembo caliper if I toast one of those too.

I guess I'll man up and start turning ESC completely off. At first I figured brakes were cheaper to replace than body panels and paint, but after this season, I'm having second thoughts!

 

[ddd4114]

do you have a picture of how you have your cooling set up? and where you have it mounted on the front end.

The pictures aren't terribly clear, but hopefully you can see what's going on.

The brake ducts are from the Ford Racing kit that is used on the Laguna Seca Mustang.

Let me know if any other pictures or info would help.

 

[Godzirra]

Go ahead and get the big boy stuff. http://www.tirerack.com/brakes/brem...upe&autoYear=2011&autoModClar=Standard+Brakes

OR get the nascar raybestos setup that they put on that roush car lol.
http://raybestosgarage.com/

 

[ddd4114]

Ouch! $4000 is a bit over my budget...

 

[Godzirra]

Ouch! $4000 is a bit over my budget...

Hahaha you and me both man. I'm just messing. I almost consider those the "show" caliper too. They make a race unfinished caliper and the carbon ceramic's if you want them.

 

[Thekid760]

http://www.fordracingpartsdirect.com/Ford_Racing_Mustang_14_inch_Brembo_Brake_Kit_p/m-2300-s.htm

or

http://www.tpsmotorsports.com/tps-14-4-piston-brembo-gt500-big-brake-system-2005-2012-mustang.html

 

[SoundGuyDave]

Dave,

It's good to know that Ford is equipping the newer non-Brembo Mustangs with what sounds like a horror show based on what you've described.

They're not THAT bad... For "novice level" or just occasional track use, they'll be just fine. If you start tracking the car regularly, though, they are, um, sub-optimal.

I would LOVE to get 12 days out of a single set of DTC-60 front pads. Before Gingerman, I was getting 4-6. Do you think the Brembo calipers would be a good upgrade in the long run for me? Calipers are easy to replace, and if taking replacement ones with me to track events means saving money in the long run, I'm prepared to do that. I just don't want to upgrade and have to pay $300+ to replace a Brembo caliper if I toast one of those too.

So far, I'm two years in on the initial set of calipers, no rebuilds, no boots, no maintenance outside of bleeding and the occasional wipe-down. LONG-TERM, you will be money WAY ahead going with the Brembo setup. The pads last longer, as do the rotors, both in terms of track-days prior to replacement, and in cost-per-lap, as well. Assume that the cost of the rotors and pads is roughly 25% more, but you get 250% of the use, well, you do the math.

I guess I'll man up and start turning ESC completely off. At first I figured brakes were cheaper to replace than body panels and paint, but after this season, I'm having second thoughts!

Bodywork is absolutely more expensive than brake parts! That said, the ESC isn't worth a shit in these cars, and honestly only slows you down, if you have half a clue on how to drive. Trailbraking with the system active is an exercise in frustration, and it's nearly impossible to really stick the tail out on corner exit either. Turn it off, and just drive within your limits.

Long story short, the Brembos are more cost effective long-term, and considerably less frustrating to maintain, as well. Stick with DTC-60 on all four corners, get the Fulltiltboogieracing.com brake shields, and if you can, figure out how to dump some weight out of that car, and you'll be smiling every time you hit the braking zones, lap after lap, after lap, after lap.

FWIW, yes, the FR500C setup (Brembo race catalog, NOT Gran Turismo stuff) will last even longer, but price is a pretty steep barrier to entry.

 

[foolio2k4]

looks like your doing something RIGHT!

 

[pcdrj]

Also, rotor cracking usually takes place during cool down. It's good practice to to touch the brakes several time on final lap and even drive the paddock for a few minutes gently applying brakes which will holds temps in a little longer.

Brake ducts can sometime shock a rotor on a long straight following hard braking.

 

[kevinatfms]

i have a set of calipers you can have that were recently refurbished if you like. they are original 06 GT calipers that are just collecting dust.

on another note, shedding weight is much easier than you would think especially at the track. remove everything out of the trunk including spare wheel/tire assembly, jack and all the finishing materials. as for overheating the brakes, yeah you have a good set of pics on how to do it properly. i was toasting my stock calipers like that every 3-4 track days using almost the same setup as you. changing pad compounds may help but initial bite may suffer at peak temps. rotors are kind of a crap shoot as you already have the 13" 2011+ setup.

the piston material is ceramic and really can take some abuse but if your cooking even the caliper slide pins i would say step up to a brembo setup. a few people on this forum can get them for quite cheap and they are worlds better in fending off the "heat monster" than the stock setup. the 14" rotors alone will pay for itself in the first few track days.

 

[DUFUS]

To save some $ over the "kit" prices I parted out the pieces from different sources and got new Brembo calipers and 14" rotors for ~$500.
Shop around, you'll find the good deals. Or look for take-offs.
You'll be glad you did. I never feared catastrophic failure or anything with the stock stuff, but maintaining/replacing them just became too much of a pita for me.
I also agree, ESC/TC totally off.

Just thought of another thing... What wheels do you have? Gotta make sure they clear the Brembos.

 

[martin_nj]

please try to run everything with the stability and traction control systems fully off before you spend any big money.

i will be running dtc70 and motul600 fluid on stock 2013 rotors/calipers in sept

i think i'll be using ducting not 100% sure

 

[jymontoya]

Sounds to me like you're simply starting to go faster and brake harder. Something the stock system, even with cooling and good pads, wasn't designed for...

$999 for the FRPP Brembo Upgrade kit from: http://www.gefracing.com/

Give them a call and tell them your track buddy sent you and heard they were on sale there. Shipping would be extra, but that's the price I picked up mine for.

Also, in my experience HAWK is all over the place with QC. Some last a long long time, some don't last long at all... even on what's supposed to be the same pad!

I can tell you where to get a set of Raybestos ST43's for the front for less than $100. PM me.