Anybody who tracks should read this.

lucid wrote

Finally, are you implying that if you pushed, say, your M3, to the point where it had no pad material left and its fluid was fully boiling, (say equip it with the nismo pads and fluid), and kept on pushing it, it would somehow fade/fail much more gracefully/progressively?

To make matters worse, many of the new BMW models actually increase brake boost as the pads heat up (Brake Fade Compensation, as they call it on their website), which tends to mask the symptoms. Perhaps Nissan uses a similar system. Not a good idea, IMO.

mastek wrote

What brand/model pad was it?

HT10 in E92 M3 at WGI. I still have the pads in pieces in my garage. Plenty of pad thickness left when they gave up and later came apart. RS19 pads were smoking under the same conditions the session before (rotor temps at paddock were similar and I was driving in a similar manner), but they held up. Pedal travel was fine IIRC. I got lucky that there was room off track and I didn't force the turn and kept the wheel straight when I realized there was no way it was going to make it. Not fun though, and gravel is messy. Still, a lesson learned. Not a good idea to operate close to the MOT. I should have backed off.

m3bs wrote

To make matters worse, many of the new BMW models actually increase brake boost as the pads heat up (Brake Fade Compensation, as they call it on their website), which tends to mask the symptoms. Perhaps Nissan uses a similar system. Not a good idea, IMO.

Good point. I don't know if Nissan is using a similar system or not.

What I find interesting is Nissan's "performance brake pad" option. They say the performance pads are for track use only on their website and list an MOT of 600F/700F. That's not exactly a "track' pad either for that car.

Pagid RS 4-2-1 pads, which are meant to be OEM equipment, have an MOT of ~950F.

Finally, are you implying that if you pushed, say, your M3, to the point where it had no pad material left and its fluid was fully boiling, (say equip it with the nismo pads and fluid), and kept on pushing it, it would somehow fade/fail much more gracefully/progressively?

Lucid - my experience with the fade issue in my E92 with stock pads, (and reported in a post somewhere) was a progressive event. At a short track, tight turns, the brakes began to go away slowly, but excalated disportionately as the car was continuously pushed hard. I terminated the run just as the brakes were beginning to totally give up, electing not to punish the car further. I am sure had I attempted another lap, an off would have occured, the cause, no brakes, and damage to the car would have been likely. Surprisingly, a close inspection of the brake system later reveal no ill effect to any components. Fluid was changed, and the car has been driven okay since, even once on the track at reduced enthusiasm
vz

von_zoom wrote

Lucid - my experience with the fade issue in my E92 with stock pads, (and reported in a post somewhere) was a progressive event. At a short track, tight turns, the brakes began to go away slowly, but excalated disportionately as the car was continuously pushed hard. I terminated the run just as the brakes were beginning to totally give up, electing not to punish the car further. I am sure had I attempted another lap, an off would have occured, the cause, no brakes, and damage to the car would have been likely. Surprisingly, a close inspection of the brake system later reveal no ill effect to any components. Fluid was changed, and the car has been driven okay since, even once on the track at reduced enthusiasm
vz

VZ, I understand that. The question is more about what would happen if you were to use lesser quality pads and fluid. The OEM E92 M3 pads are pretty decent as far as stock parts are concerned IMO. They certainly don't vanish in 10 minutes.

On the other hand, if the argument is that there is something fundementally wrong with the design of the nismo brakes in that the calipers/pistons transfer an unusually (relatively speaking) high amout of heat to the fluid and that is what's causing the abrupt failure, that would be a problem. But one cannot arrive at such a conclusion based on what has been presented. The test I proposed would be informative: equip the M3 with the stock nismo pads and fluid, push it until the pad vanishes in 10 minutes, and see how the system fails.

The test I proposed would be informative: equip the M3 with the stock nismo pads and fluid, push it until the pad vanishes in 10 minutes, and see how the system fails.

Lucid, what a shame you do not still have your E90. I would come to the track and take videos of you running the test - from the far side of the track of course.

Seriously, that would be a good comparison, and no doubt would answer most of the questions raised here. My argument with this is that they pushed the car until it broke, which was not necessary to prove the poor quality of braking. All of my experience with brake fade is that it did not take an engineering degree to notice it coming on, and fairly easy to predict the outcome if continued abuse was applied. The four turns alone at VIR afforded plenty of opportunity to determine the brake condition as you completed laps, plus several other brake applications necessary to settle the car. These four turns requiring maxium threashold braking, and if really pushed as in racing, continued braking through the beginning of turn in. At a minimum, some indication should have been evident - increased stopping distance, brake pedal feel, car behavior. They should have never put that car in the barrier.
vz

lucid wrote

How is the example I gave of pads letting go completely irrelevant? You offer no basis for making that claim. The consequences of pad "failure" of that nature is exactly what happened to the authors. Keep in mind the exact cause has not been identified. They are just speculating although it is clearly related to overheating.

Moreover, the article states the stock nismo pads were literally gone/vanished in 10 minutes (it appears that is what is illustrated in the picture). When there is almost no pad left, heat transfer into the fluid increases. They also state this as a potential factor.

The pads show excessive wear but not a catastropic failure. That is important. The irrelevant thing is whether or not I have destroyed pads personally.

lucid wrote

The tire example is very relevant as well. The official response from Nissan explicitly states that they are not surprised because the pads are not speced for racing on a track.

It surely is not based on the DIFFERENCE between the Nissan and all other cars. Tires would not cause this difference, period - all cars would behave the same.

lucid wrote

I haven't avoided anything. I responded to that point many posts ago. It appears the OEM nismo pads and fluids are not on par with BMW and Porsche OEM pads and fluids. If Nissan optimized their street setup differently than other manufacturers for whatever reason, that is their choice. Maybe they were tyring to save a hunderd bucks, or maybe it was a supply chain issue, etc. There is nothing wrong with that as long as the car does fine on the street. The marketing language is jibberish. Those are not technical specifications.

You have and are still avoiding it. The issue is the singularity and severity of the problem with the Nissan. It is not just a cheap pad to save some money - which you imply is excuseable - and it would be if progressive fade was the only result.

lucid wrote

Finally, are you implying that if you pushed, say, your M3, to the point where it had no pad material left and its fluid was fully boiling, (say equip it with the nismo pads and fluid), and kept on pushing it, it would somehow fade/fail much more gracefully/progressively?

No, it does not even make sense to speculate on this. It all comes down to the singularity and severity issue. The repeating of the "scary" track braking event and crash was adequately reproduced in their straight line controlled tests and the evidence is fairly convincing (sure not proven beyond a shadow of a doubt) that this is a selective boiling problem and a SYSTEM problem not a pad or fluid specification problem.

The article sums it up and you keep pushing back against this conclusion,

that the NISMO Z, an even sportier version of a sports car, should be equipped with brakes competent enough to survive a few hot laps. And it’s worth noting that we’ve never experienced such hellacious brake degradation in the history of our Lightning Lap events.

I've made my point, I'm think I am done with this topic.

Shame on Nissan.

No Swamp, I'm not avoiding anything. You claim that the requirement, "A sports car equipped for street use should not exhibit non-progressive brake failure on a track while being raced" as a universal product requirement. That's just your opinion. You can capitalize it, write as many "Period"s after it, but that doesn't make it a universal requirement. It is still your opinion. Even the magazine is cognizant of this, and they state their opinion on that with a sentence that begins with, "It’s our view, however...." Nissan clearly developed the requirement around that based on a street usage scenario.

As far as I can tell, there is no evidence that the stock setup has; 1. failed on the street, 2. failed without giving any warning on the street. As long as those events haven't occurred, what has happened on the track is irrelevant for the stock car, and the manufacturer has met its requirements associated with street use (and cannot be held responsible for what happened on the race track).

The test I suggested would be meaningful, and it would constitute at least an apples to apples comparison to explore if the nismo brakes indeed have brake failure problems without a warning on a race track.

You keep on saying the "selective boiling" problem is independent of pad and fluid selection; the article itself suggests otherwise (why do you think they posted pics of a vanished pad in the article and associated that with the boiling of the fluid?) and recommends to the reader to upgrade the pads and the fluid in addition to cooling ducts.

And, you can boil the oem fluid in an M3 or a Z4M as well. Just a matter of time frame. We have not established that those cars would somehow respond drastically differently to that situation by failing gradually independent of the quality of the pad and fluid in the system, which would be the point of the test I proposed.

Moreover, we don't have any specific information on how the OEM nismo pad behaves when its MOT is exceeded. (And it seems to have a very low MOT since the performance pad "upgrade" they are offering has an MOT of only ~700F). I don't see how the straight line test teases this out. Something similar to what happened to me could have happened to them on the track. Plus, the straight line test with the OEM setup did not actually replicate what happened to them on the track:

Although the brake-pad fade was dramatic, at least it happened somewhat gradually, far more so than during our wild ride at the Virginia track.

von_zoom wrote

Lucid, what a shame you do not still have your E90. I would come to the track and take videos of you running the test - from the far side of the track of course.

Seriously, that would be a good comparison, and no doubt would answer most of the questions raised here. My argument with this is that they pushed the car until it broke, which was not necessary to prove the poor quality of braking. All of my experience with brake fade is that it did not take an engineering degree to notice it coming on, and fairly easy to predict the outcome if continued abuse was applied. The four turns alone at VIR afforded plenty of opportunity to determine the brake condition as you completed laps, plus several other brake applications necessary to settle the car. These four turns requiring maxium threashold braking, and if really pushed as in racing, continued braking through the beginning of turn in. At a minimum, some indication should have been evident - increased stopping distance, brake pedal feel, car behavior. They should have never put that car in the barrier.
vz

VZ, we can maybe run the test with me in your E90?

Good point about pedal feel. If the fluid was indeed boiling, why did they not notice something there?

I remember Junior saying he didn't have any fade when he cooked his brakes.

aus wrote

I remember Junior saying he didn't have any fade when he cooked his brakes.

Right, that was massive and abrupt brake failure in an E9X M3 that was pushed hard by a pro, and it had serious pads, fluid and even ducting IIRC.

lucid wrote

Right, that was massive and abrupt brake failure in an E9X M3 that was pushed hard by a pro, and it had serious pads, fluid and even ducting IIRC.

Hmmm so you suggest that sudden catastrophic failures should serve to offer the same level of criticism to the OEM for these cases:

1. A Pro driver (literally) pushing an M3 really hard with a heavily modified brake system.
vs.
2. A journalist from a magazine doing hot laps in a completely stock car.

That really does not cut it.

Last Friday I had brake issues again. My pedal almost went to the floor by the end of a half day!! Using Carbotech xp-10 pads and Castrol SRF fluid. The strange thing is, it remained like that (requiring long pedal travel) even after the track session, on the street, until I flushed the brakes. The brake fluid looked very clean, like new. The front XP-10 are 1/3 gone.
BUT no steering fluid issues!!!

TrackRat wrote

You may have a master cylinder issue as the XP-10 and SRF should be fine for very fast track driving.

You may be right. Just cannot explain why the pedal travel did not improve when everything cooled down. I had increased pedal travel before on track with the same setup but came back to normal when cooled. Not now.

Just too many issues with the barkes on the M3. Is the GTR better, anyone??

swamp2 wrote

Hmmm so you suggest that sudden catastrophic failures should serve to offer the same level of criticism to the OEM for these cases:

1. A Pro driver (literally) pushing an M3 really hard with a heavily modified brake system.
vs.
2. A journalist from a magazine doing hot laps in a completely stock car.

That really does not cut it.

IIRC, the M3 only had its pads and fluid modified in a manner that any enthusiast who might visit the track regularly would. And the addition of cooling ducts can only help rather than tax the OEM system that was being used. I have no idea who the C&D driver was—he/she might have been a pro as well.

One can argue that using high MOT pads and fluid would naturally raise the maximum operating temperature of the system, and stress components in a manner that they were not design to cope with, but then we go back to the nuances of what these cars are and are not designed for, etc. Regardless, yes, that example is anecdotal, but I’m not in any way close to being a pro, and as I’ve mentioned, I also experienced non-progressive brake failure in my M3.

One can blame my experience on the pads, but if we adopt your point of view, it should actually be viewed as a system failure as well since the net energy flow into the M3 system is positive over time, and temperatures never really stabilize to oscillate within an acceptable range when the car is pushed continuously (I was seeing rotor surface temperatures of 1100F+ at the paddock after 40 minutes of driving on a fast track). Perhaps, the M3 system is just as flawed as the nismo system in that sense, and it merely gets away with it in a magazine track test by delaying/avoiding the non-progressive failure issue by using larger rotors, and pads and fluid with higher MOT. (And that was the point I was making with the UHP vs. snow tire example; that these cars are not using similar spec “tires”—oem consumable brake components—and hence their performances and failure modes might vary accordingly. We can leave rotor sizing out of it though since that doesn’t exactly factor into the consumables that should be chosen for the application discussion).

Anyway, going back to the nuances of the “non-progressive” nature of the brake failure, which is what you are interested in discussing, I’ll point a few other observations the magazine made in the post-track test that indicate there were significant warnings in all 3 configurations they tested:

1. OEM configuration (as I referenced in my previous post): fade warning.

Although the brake-pad fade was dramatic, at least it happened somewhat gradually, far more so than during our wild ride at the Virginia track.

2. OEM fluid + “mildly upgraded” pads: instability warning.

The next two stops were spooky: Mashing the brake pedal caused the Z to veer quickly and dramatically, requiring steering correction to keep it in a straight line…The next stop fully boiled the fluid and caused the braking force to evaporate completely.

If they could deal with it during 2 back to back 100-0 events, no reason to think they shouldn’t have been able to do the same during a 135-50 event. Plus, upgrading the pads only made the fluid more of a weaker link (since they were able to execute a higher number of cycles and the operating temperatures increased as a consequence), and brings the specifications of the oem fluid more to focus.

3. “Mildly upgraded” pads + ATE fluid (which is not the fluid I would chose for a 350hp 3400lb car without cooling ducts): fade warning.

Considering 23 essentially fade-free stops, not only did the fluid extend braking performance, but stops 24 through 31 showed gradual fade—a warning to the driver that things are starting to overheat—which made this by far the best setup.

Also, never mind the fact that with the completely OEM setup, pedal travel even at the mild 0.5g stop went from 1.25” to a whopping 5”.

So, based on these data, how can one conclude that: 1. Pad and fluid selection has no bearing on how the system fails since the type of warning changes (progressive or non-progressive), 2. The Nismo setup does not provide any warning prior to brake failure when punished?

I have criticized their judgment by saying they should have at least checked the MOT of the pads and the fluid before taking it to the track; based on these data, a mildly upgraded setup should have saved the car during their test.

You are criticizing the brake system by saying it should not fail in a non-progressive manner on or off the track. My response to that is that there are unanswered questions as the system has given some type of warning during the post-failure tests, and there are other anecdotal examples of other cars (the M3) failing without warning on a track, and the non-progressive nature of the Nismo failure—if that was indeed the case as we have no way of verifying how it actually failed—might be related to its oem pads and fluids not being on par with other oem equipment.

I will agree with your assertion, which may very well be true, and treat it as a conclusion when and if the unanswered questions are answered. I have no issue with joining you and pointing a finger at Nissan when there is conclusive evidence, so this is not about me defending a car company. I could care less. My main criticism has been that the accident could have been easily avoided if due process had been observed. We do seem to be on different wavelengths indeed, and I hope that this long post bridges that gap somewhat.

no matter how much success a journalist or pro racer or amateur has had at a track with an OE setup -- you should ALWAYS UPGRADE TO TRACK PADS & HIGHER TEMP FLUID before taking ANY car to the race track. period.

If you want to track = you must upgrade the brake system = or risk failure/fade/sudden loss of stopping power.

mastek wrote

If you want to track = you must upgrade the brake system = or risk failure/fade/sudden loss of stopping power.

You are way too harsh with that statement!There are lots of fairly quick people that come come out in their E9X M3's and have no issues with brakes.I know of least 2 people that are still on their orginial pads & fluid after a half dozen track days.I only just changed to a race fluid and yes it helped but I was far from dangerous with the stock setup.at least on a E9x there is a lot of warning signs before the brakes go away.

there is a lot of warning signs before the brakes go away.

That has been (was) my experience.
vz

Gearhead999s wrote

You are way too harsh with that statement!There are lots of fairly quick people that come come out in their E9X M3's and have no issues with brakes.I know of least 2 people that are still on their orginial pads & fluid after a half dozen track days.I only just changed to a race fluid and yes it helped but I was far from dangerous with the stock setup.at least on a E9x there is a lot of warning signs before the brakes go away.

This is the problem with complacency - it sneaks up on you.
Depending on the individual, your level of track experience and speed goes up every time you go out. And if you happen to get quicker faster - you might end up crashing your car because your brakes faded when you had someone in front of you, in a braking zone.

Why risk it?

It takes me 30 minutes to change my brake pads
and the fluid stays in all the time (street & track)

There are numerous stories of people being "shocked" "surprised" .. when they lost braking all of a sudden -- when they have been running the same (OE or not) setup for months.

"better safe then sorry" ... will ever apply more, ... then when your brakes fail in the most critical time.

It takes me 30 minutes to change my brake pads

Is that for all four corners? Thanks
vz