Losing my damn mind: Miata Track Pads Glazing nonstop

I'm going to post about this again. I'm sorry guys - I'm losing my mind over this problem. (new forum layout isnt helping either lol)

I've got a '92 Miata that I run in DE2 (intermediate) with NASA. It has NA8 (94+) spec brakes on it. It's a slow/light car - 104whp, 2450lb with me in it. Running 5ish seconds off of SM pace with Yoko AD08 tires. The entire brake system is new. Master, flex lines, calipers, rotors, pads - all are new. I'm going to carefully try to state everything objectively only.

2 weekends ago I was at Summit. On the front of the car were new GLOC (similar to Carbotech) G12 pre-bedded pads with new rotors.  Rotor bedding had been performed.

Session 1: Brakes feel great

Session 2: Brakes start to fade. Remove them to find them to be glazed. Vendor at track sold me a set of ST43 front pads to use instead.

Session 3-4: Brakes are ridiculously amazing. First time all year I've been able to actually enjoy myself on track where there was a braking zone involved.

Session 1-2 on Sunday: Repeat from Saturday. Good first session, 2nd session I pull the pads after they were fading and found them to be glazed.

Session 3-4 on Sunday: Blah. Scrub glaze from pads, do a few laps, brakes start to feel better then towards end of session they start to fade. Pull pads, glazed again. Repeat. Blah.

Monday I cleaned up the glaze from the G10, G12 and ST43 pads I own. Each pad has its own rotor it's being used for. The GLOC pads look glazed instantly. ST43s looked good.

Tuesday I went to NJMP Lightning. Same f-ing g-damn S*&(U&(*$%@ over and over. Go out, brakes feel questionable, then start to fade. Pull the pads, all glazed over.

R12 pad: https://imgur.com/xJvwiGM

ST43: https://imgur.com/mXlcFGg

Yesterday I tried to do some more investigation. I drove my street NA8 car without using the brakes and then the track car in the same manner. Both cars had almost identical pad/rotor temps, so I don't think the brakes are dragging. For what it's worth, I tried running with pad spreader springs and saw no difference.

I've talked to 949Racing, two SpecMiata builders, posted on miataturbo.net, local SpecMiata FB group - I'm running in circles. Guys both slower and faster than me don't mess around with their brakes, they just bolted on pads and have been having fun. Yet here I am taking them off after every session - bleeding, adjusting, cleaning, replacing with no luck. Every damn lap all season (except for those 2 sessions) has been a nerve-racking game of "will my pads work this turn?" I'm really running out of patience.

Naturally the recurring comment is WHY DONT YOU JUST BUY A SET OF HAWK PADS? Ok, that will make my 3rd set of pads in 3 weeks. They're not cheap. After running 3 diff compounds I think it's safe to rule out pads as the culprit.  I'll do it if it fixes it. I'll do anything that will fix this problem. But every bone in my body is screaming that this is not a pad issue.

The problem according to many folks is that they think I'm glazing the pads by not braking hard enough. I'm having a hard time buying this but I'm open to suggestions on how to fix it. Here's how my pads looked like after just a quick drive around the block after cleaning off the glaze (10 front, 8 rear). 600+ front temps, 400+ rear so they WERE up to temperature.

https://imgur.com/5kh3j9I
https://imgur.com/dFmKXtP

The rears both looked like this. Difference in photo is just wiping away the dust. Possibly high spots from sanding????

https://imgur.com/a/9lbCb

If the pads are glazed over after just a quick drive to get them up to temp, what gives? Why is this so damn difficult? It's just a miata and I just want to have fun in HPDE :( Help save my sanity.... plenty of people street drive on these pads with no issues, I can't possibly imagine that my medium-hard stops to break them in would do this. And my friend who is 2 seconds faster than me is still running STOCK pads. Gahhhhhhhhhhhhh......

If you are experiencing fade with real racing compound pads and the same hardware others are racing with successfully - there may be something to the argument that you could be causing the issue with technique.  As a long time instructor and racer it is my observation that almost everyone from beginner thru advanced brakes too much and often in the wrong way until they focus on it and train themselves to do it properly unconsciously. When in a stressful situation like slowing from maximum speed we go with what we know and if what we know is street application for many years of muscle memory - it's wrong.

When you brake you should squeeze (not stab) to maximum braking as quickly as possible and release pressure over the end of brake zone. Braking harder, over a shorter distance rather than holding say, a constant 90% pressure for the whole brake zone.  It is also crucial to release them gently to keep the car planted - which will allow you to go into the corner faster (which will lead to less braking as confidence grows).

Rather than me repeat the text of "Going Faster" here :) I would advise you to ask the chief instructor to pair you with someone known for teaching good advanced braking technique and spend a day focusing on just that aspect of your driving. Even if it turns out not to be the root of the problem it won't be wasted effort. 

It's awfully difficult to brake later when you can't trust your brakes. I've been braking as hard as I can and moving the markers back if I find myself confident - that's only ever happened for 2 sessions all year.

Just to be clear.  The pedal stays high and hard but the car doesn't slow, correct?

APEowner said:

Just to be clear.  The pedal stays high and hard but the car doesn't slow, correct?

Correct. Except then I have to apply more pressure since they're glazed... which creates more heat... and then eventually I can boil the fluid.

I think what Huckleberry is suggesting is that you may be trying to use hardware to fix a software problem. How are you reading temperatures? And are these rotor temps? 

mazdeuce said:

I think what Huckleberry is suggesting is that you may be trying to use hardware to fix a software problem. How are you reading temperatures? And are these rotor temps? 

That's why I posted pics of the pads after just running them up to temp. Do they look right or not? There cannot be a software problem for those pics (right?), it's just a 5 minute drive with some moderate-hard stops. I couldn't have overheated them there.

IR sensor. Fluke 556, not harbor freight crap. Yes, rotor temps.

Wait, you're in a Miata and you use the brakes?   (said by a long time Miata racer and instructor.)

Just kidding.  Have you talked to the GLOC guys? They are usually pretty responsive from when I delt with them.

Also, I second having someone analyze your braking technique.  I have retaught instructors how to brake before.  I also ask for a 2nd opinion every now and then as an instructor myself.  

I only brake where I have to... I've watched plenty of SM videos to make sure I'm not doing something dumb.

I emailed Danny@GLOC. We'll see if I hear back.

I'd love to put an instructor in my car but every spare dollar has been going towards buying (and re-buying) brake components so I haven't been able to afford a 2nd race seat and harness. And I've been missing hours at work tearing the car apart over and over trying to figure out what's wrong. I doubt an instructor would be willing to ride in my car without matching safety gear. And I have a lot of worries letting somebody else drive the car when I know I've got braking issues.

When you de-glazed the pads, did you clean up the rotors too?  I'd also be tempted to try a set of slotted rotors.  They'll wear the pads faster, but they might also keep them from glazing.  

rslifkin said:

When you de-glazed the pads, did you clean up the rotors too?  I'd also be tempted to try a set of slotted rotors.  They'll wear the pads faster, but they might also keep them from glazing.  

All of the above. Run as is, clean up, replace and use brand new. No difference.

No Sm cars are allowed slots or ducting, so that's not the issue here.

I used to glaze the pads on my Honda all the time, I was running a lot of dual use/autocross compounds because everyone said a Honda didn't need a full race compound for DE1/2.  Well, like Huckleberry said, the problem was all software.  I wasn't braking right, so they'd get hot and start to glaze, then I wouldn't trust them, so I'd brake even wronger, then they'd get hotter still so I'd brake even wronger, etc.  It's a negative feedback loop.  Everyone said "Brake later and shorter" but when you're doing 120 into a braking zone and you don't trust the brakes, you'll never learn to do that.

Eventually I just dropped the coin for a full race compound and it was like a light bulb turned on.  My braking zones shrunk dramatically and I haven't glazed a pad since, even when I take full weight street cars on stock pads out on track. 

I don't know anything about GLOC but it seems like you're still running a dual use pad and not braking correctly like I used to do.  It's all well and good for us instructors to say you're not braking correctly, but I get it, if you don't trust your pads it's hard to learn what braking correctly feels like.  So do what I did, pull out your wallet and make it rain Hawk DTC-60s or whatever their endurance pad is.  Or get someone in the passenger seat with steely nerves who can berate you into not braking early.

 ^ That's exactly feedback loop I've had.

The G10, G12, and Raybestos ST43 pads are all full race. And they're not cheap, especially once you buy new rotors to go with them. Hard to justify making it rain a fourth time... but I'll do it if it solves the problem. But I'm 99.99999% sure that the issue is either with me or the car, not the pad.

So it looks like you're using the GLOC R12 rated for 173-1860F, correct? Unless you see smear marks all over the rotors there's no way you're overcooking those pads on that car with those calipers.

If you glazed them on the drive to the track it would show up immediately. I'll join the chorus & speculate that either your pedal technique factors in (since they perform fine for the 1st session & deteriorate after that), or those pads are just overkill for your purposes.

For reference, I ran a ~200Lb heavier faster (turbo) '95 on Hawk DTC60/30 with lower temp ratings than those pads & they never cooked.

I want to know more about your pad bedding technique. I don't know anything about GLOC pads, but whenever I've had a glazing issue (rare) it's come down to insufficient bedding.

Dashpot said:

So it looks like you're using the GLOC R12 rated for 173-1860F, correct? Unless you see smear marks all over the rotors there's no way you're overcooking those pads on that car with those calipers.

If you glazed them on the drive to the track it would show up immediately. I'll join the chorus & speculate that either your pedal technique factors in (since they perform fine for the 1st session & deteriorate after that), or those pads are just overkill for your purposes.

For reference, I ran a ~200Lb heavier faster (turbo) '95 on Hawk DTC60/30 with lower temp ratings than those pads & they never cooked.

 

I'm towing to and from the track.

I just ordered a set of DTC60s. So I'm going to Watkins glen with FOUR sets of brakes. Jesus christ.

Keith Tanner said:

I want to know more about your pad bedding technique. I don't know anything about GLOC pads, but whenever I've had a glazing issue (rare) it's come down to insufficient bedding.

I'm following these instructions:

https://forum.miata.net/vb/showpost.php?p=2756334&postcount=58

Bed them harder? Softer? I had Dan @ 949 look at my most recent pics and he said they looked fine. I'm tearing my hair out over here. How is shiny and smooth not glazed?

Just ordered DTC-60s. God help me - if I show up to Watkins with four sets of brakes and still can't get this damn car to work, I don't know what I am going to do.

In reply to Blaise :

Make sure you scuff the rotors and bed the pads according to Hawks instructions... then let them cool. Then, before you drive the car - give the keys to an SM racer who hasn't balled one up in practice and tell him to do a a few hot laps and tell you what he thinks of them.

If he has no complaints... go to back to school.

FWIW, I've run DTC-60s on a 2900lb E36 and a 2200lb E30 race car, at race pace at Summit Point in 100+ temps,  both making twice the power you are dealing with, running full slicks  and never had an issue - even when the brake ducting fell off from some overly um... optimistic bump drafting :) If you aren't clinging to them when you shouldn't you won't overheat them in a Miata.

Blaise said:

Keith Tanner said:

I want to know more about your pad bedding technique. I don't know anything about GLOC pads, but whenever I've had a glazing issue (rare) it's come down to insufficient bedding.

I'm following these instructions:

https://forum.miata.net/vb/showpost.php?p=2756334&postcount=58

Bed them harder? Softer? I had Dan @ 949 look at my most recent pics and he said they looked fine. I'm tearing my hair out over here. How is shiny and smooth not glazed?

I'm mostly interested in the first three steps, not the rotor bedding.

Basically, to bed pads, you have to get them up to full temp and hold them there for a little while. Pads intended for race use obviously need higher temperatures. I prefer bedding in a controlled environment where you have more control over your braking speeds, tracks obviously put some requirements/limits depending on how they're designed. In other words, I bed on straight roads. A couple of warmup stops (not a full stop to zero, but releasing the brakes at around 5 mph), then a series of progressively harder stops. You should smell the pads, but keep going even if they go hard. Street compounds take stops from about 45-50, race compounds need to stop from 60-65 to generate more heat. Then let them cool.

^ I can do that. Only issue is, still nobody (including Dan from GLOC) has commented whether those pads look fine after bedding. I also used pre-bedded R12s at summit the first time out. How did I overheat those!?

Also, I'm not really bedding them. The rotors have a transfer layer on them, I just need to get the surface of the pad to match the rotor after scuffing off the glaze. If they're even glazed... like I said, losing my sanity here.

Guy ~2 seconds faster than me is still on street pads... other guy is on STOCK pads. Plenty of folk in my group running same pads.

Everybody has one thing in common: No problems.

You could also look at slotted (not drilled) rotors to help keep the pad surfaces fresh.

I second the recommendations on your braking technique and the bedding procedure.

There's also a potential issue with changing compounds without changing rotors or at least roughening up the surface of the rotors to accept the different pads.

I'd order a second set of rotors, slotted is my preference, and if you still have issues at the track put the new rotors on with the pads of your choice and go bed them in and see how that goes for the next session.

Another thought:  Try swapping cars with one of the other Miata folks or ride along with them while they drive so you can see if they notice anything or if there's a technique issue, etc.

Stefan said:

You could also look at slotted (not drilled) rotors to help keep the pad surfaces fresh.

I second the recommendations on your braking technique and the bedding procedure.

There's also a potential issue with changing compounds without changing rotors or at least roughening up the surface of the rotors to accept the different pads.

I'd order a second set of rotors, slotted is my preference, and if you still have issues at the track put the new rotors on with the pads of your choice and go bed them in and see how that goes for the next session.

I'm running 3 sets of rotors as well unfortunately.

I'll probably buy another set and have 4 for this weekend. Ugh.

Blaise said:

^ I can do that. Only issue is, still nobody (including Dan from GLOC) has commented whether those pads look fine after bedding. I also used pre-bedded R12s at summit the first time out. How did I overheat those!?

As I said, I don't know anything about GLOC. I don't know if their pre-bedded pads are worth anything. I would be bedding them.