Spend any time at the track and you’re bound to hear about–or even experience–brake fade. When 3500-pound machines get into triple-digit speeds, repeatedly turning all that kinetic energy into heat is going to have some side effects. Knowing how to spot the various heat-related failure modes–and how to correct them–is key to success in braking zones.
When we talk about …
Just out of curiosity, had anyone ever experienced pad fade on track? I've experienced fluid fade, but never personally had a pad fade.
In reply to BA5 :
Yup. A coworker of mine overheated some Hawk HP+ pads badly enough to send him far off the track. I've had various pads hot enough to start to fade but have never let them get that far.
In reply to BA5 :
Yup. It was also Hawk HP+'s. I lost the pads entering T2 at Laguna Seca in my STi. I started pressing the pedal as usual and it just kept going down to the floor. A little e-brake got the car to rotate just as I left the track. I was about 5ft into the gravel trap and decided to see if the awd would pull me out. Luckily it did. There was no previous feedback that the pads were overheated.
Nursed the car back to the pits and pulled the front wheels off the car and the pad material poured out of the wheels like sand at the beach. Haven't used Hawk pad since that event.
myf16n said:In reply to BA5 :
... I started pressing the pedal as usual and it just kept going down to the floor...
Wouldn't that be fluid fade?
Yep that would be fluid fade, with pad fade the pedal doesn't really travel further than usual and certainly wouldn't go to the floor. You would find yourself using more pedal force than usual and not getting as much braking, the pedal may be pressed down a little further because of this but it would not be soft.
I'm sure the fluid boiled too, but it was definitely pad failure. They didn't fail by becoming glazed. They were only a few days old (full thickness) when this happened, and when I removed the pads in the pits there was no braking material on the backing plates. Zero. The pedal went to the floor as I was braking at T2, but it did come back enough to allow me to get back to the pits without relying on the e-brake. I'm pretty sure that the additional pedal travel was mostly related to the additional travel of the caliper pistons due to the loss of pad material.
EDIT: I read "pad fade" and jumped in with comments about pad failure. Sorry for taking the discussion down a different road.
BA5 said:Just out of curiosity, had anyone ever experienced pad fade on track? I've experienced fluid fade, but never personally had a pad fade.
Sure, at the basic level it manifests as a brake pedal that you have to push harder to get the car to stop. Mild cases you may not really notice, but if you're paying attention then there's plenty of warning before it gets to the level of Keith's coworker. :)
Also, the number of brands of high temp fluid is impressive these days. Used to be there were only 4 or 5 entries on most lists you could find, with Motul 600 being second only to Castrol SRF. Now that Motul is in the bottom half!
You usually get an olfactory warning before pad fade - the person riding shotgun in that Miata that went off track could smell it on the lap leading up to the failure. But my coworker was new and I think he wanted to impress everyone with his speed and, well, there was some bad judgment.
Overheated pads feel a lot like glazed pads. They just lose their mu. They can also start wearing very rapidly if they're outside their comfort zone, which may be what happened to myf16n.
BA5 said:Just out of curiosity, had anyone ever experienced pad fade on track? I've experienced fluid fade, but never personally had a pad fade.
I abused the brakes on an ITC Corolla so bad that I cooked the wheel bearings. My friends who owned the car had used a really high quality Motul brake fluid so it never boiled but the pads disintegrated.
The brake pedal remained solid the whole time but there was less and less braking with each lap. I finally started chucking the car sideways to slow it down for the faster corners and only using the brakes in the two hairpin corners.
The right front wheel bearing (what was left of it) seized on the last lap causing me to spin and handing the lead back to a friend in a 510. Note I'd been instructed to drive the car as fast as it would go regardless of the consequences (The two guys that owned wanted to see what it would do and reveal any weak spots).
The metal parts of the pad had turned blue; the rotors were also trashed but they were able to salvage the right front spindle.
I don't remember what brand of but they were something better than the basic street pad. Thankfully the car only had a top speed of about 90mph so scrubbing off 20mph for the corners wasn't that hard.
I'd sure hate to experience pad fad in a big BMW on a track with heavy braking.
I have had brake fade on my GTO (fat and heavy). The pedal was still good and firm, but no mater how hard you tried to push, the car just would not slow down. It was like the pads had been greased and you were not along for the ride.
BA5 said:Just out of curiosity, had anyone ever experienced pad fade on track? I've experienced fluid fade, but never personally had a pad fade.
We get pad fade occasionally on new cars we test at the FIRM. it's rare, but it happens. I bet if we looked into it we'd find that they may have all been with the same person before they came to us and that person was a notorious brake dragger and had glazed the pads over. Not saying that's what happens, just that it wouldn't surprise me.
In reply to Tom1200 :
This confirms what I have suspected, I had all 4 wheels hubs go bad at just under 20k miles in a new WRX with a half dozen plus track days. To their credit Subaru dealer replaced them no questions asked even with two piece rotor and track pads installed. Only comment from the service rep was "that's odd with such low miles". So I now claim Subaru sponsorship for my track days
TR7 said:I have had brake fade on my GTO (fat and heavy). The pedal was still good and firm, but no mater how hard you tried to push, the car just would not slow down. It was like the pads had been greased and you were not along for the ride.
I get there in my S60R in a remarkably short period of time on backroads. Maybe because they are all right angle turns so there is a lot of 65-20-65-20 happening?
Feels just like when it is 35 and raining and the pads ice over.
myf16n said:In reply to BA5 :
Yup. It was also Hawk HP+'s. I lost the pads entering T2 at Laguna Seca in my STi. I started pressing the pedal as usual and it just kept going down to the floor. A little e-brake got the car to rotate just as I left the track. I was about 5ft into the gravel trap and decided to see if the awd would pull me out. Luckily it did. There was no previous feedback that the pads were overheated.
Nursed the car back to the pits and pulled the front wheels off the car and the pad material poured out of the wheels like sand at the beach. Haven't used Hawk pad since that event.
Sounds like they weren't bedded in. Hawk pads last a long time for me if they are bedded in, or get absolutely destroyed in 1 session if I don't.
Also, HP+ pads are probably not a great match for a fast car and open lapping.
wvumtnbkr said:Also, HP+ pads are probably not a great match for a fast car and open lapping.
If you're overheating pads, it's pretty much guaranteed you have a mismatch between your car, use and pad choice :)
Keith Tanner said:wvumtnbkr said:Also, HP+ pads are probably not a great match for a fast car and open lapping.
If you're overheating pads, it's pretty much guaranteed you have a mismatch between your car, use and pad choice :)
Learning is fun (or terrifying; both?).
TR7 said:I have had brake fade on my GTO (fat and heavy). The pedal was still good and firm, but no mater how hard you tried to push, the car just would not slow down. It was like the pads had been greased and you were not along for the ride.
I had one of those GTOs. Fun car to drive. I had a guy at the track day ask me to stop 'steering with the gas pedal'. The brakes on it always sucked no matter what I did, however.
wvumtnbkr said:Also, HP+ pads are probably not a great match for a fast car and open lapping.
Frankly, I've yet to find an application for which HP+ *are* a good match. There aren't many people who want the noise and dust of a track pad, but don't want the fade resistance. :)
codrus (Forum Supporter) said:wvumtnbkr said:Also, HP+ pads are probably not a great match for a fast car and open lapping.
Frankly, I've yet to find an application for which HP+ *are* a good match. There aren't many people who want the noise and dust of a track pad, but don't want the fade resistance. :)
Agreed, with a caveat.
I just ordered a set for my racecar. They go on the rear of my rx7 to keep the stock brake balance consistent with a more aggressive pad up front.
codrus (Forum Supporter) said:wvumtnbkr said:Also, HP+ pads are probably not a great match for a fast car and open lapping.
Frankly, I've yet to find an application for which HP+ *are* a good match. There aren't many people who want the noise and dust of a track pad, but don't want the fade resistance. :)
They have been great on my 944. Track car that gets driven too and from. They have held up really well on track, consistent, fade free, and long lasting. The 944 is also much lighter and much slower than my GTO. I would imagine the HP+ will do fine for light track duty on lighter cars.
TR7 said:codrus (Forum Supporter) said:wvumtnbkr said:Also, HP+ pads are probably not a great match for a fast car and open lapping.
Frankly, I've yet to find an application for which HP+ *are* a good match. There aren't many people who want the noise and dust of a track pad, but don't want the fade resistance. :)
They have been great on my 944. Track car that gets driven too and from. They have held up really well on track, consistent, fade free, and long lasting. The 944 is also much lighter and much slower than my GTO. I would imagine the HP+ will do fine for light track duty on lighter cars.
They're good for about a lap and a half of a kart track in a turbo Miata. That track isn't usually hard on pads, and the R4S has no problem handling it.
Getting pad fade was never hard on any sort of street compound that you took into competition, but with a good competition compound it just never happened.
I ran Ferodo DS-11 for many years and the only issue was that it didn't stop well until it was hot, so I dragged the brakes using my left foot on the pace lap, which helped but wasn't always enough - many times I would have to broad slide through the hairpin at the end of the longest straight on the first lap.
I switched to other compounds later on when asbestos containing pad materials became a no-no, that were quicker to attain heat but none of them had quite the really high hat operation that DS-11 did. Fortunately both my race cars were sub 2000 lb. so that didn't matter.
Today I'd recommend Porterfield R4 race compound or R-4S for street. EBC also does some good compounds.
Every time I scroll past this title, I read Brain Fade...
I could use help there, too.
In reply to BA5 :
Yes, I was running OEM pads on my 2018 F80 M3. I am tracking it more this year, and had brake fade at 4th session, next to last lap and had pad fade, braking from 130 mph to 50 mph going into a turn at Summit Point Motorsports park. I have upgraded to the Turner Motorsport performance brakes and have Castrol React brak fluid now. I will try it out on the next track event later this month.
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