This may explain better then me.

 

Pad fade
Pad fade can be caused by several factors. All friction materials have a coefficient of friction curve relating to temperature. Friction materials are designed to work at an optimum temperature when the coefficient of friction is the highest. When brakes are used too frequently, if the pad material is not adequate for the temperature, then the coefficient of friction can decrease. Brake materials are different, and with enough temperature the material can melt and cause the coefficient of friction to rapidly decrease to the point where the material will melt and/or change its frictional characteristics and cause a lubrication effect.

As temperature increases, the friction material can melt and the resins that bind the friction material can vaporize and "out-gas". These vaporized gases prevent intimate contact with the rotor which, in turn, reduces friction. Some pad materials change slowly at elevated temperatures while other materials react with a sudden and dangerous loss of friction. The result is "glazed" brake pads and rotors.

 

If you have sl​otted rotors the effect can be reduced however the best answer is to upgrade to bigger calipers and rotors.

​

From the above description and the looks of my rotors it sounds like that's exactly what happened. I also note: "Some pad materials change slowly at elevated temperatures while other materials react with a sudden and dangerous loss of friction." As I wrote in my OP, during the last turn I had a very sudden and pronounced loss of braking force, the car just wouldn't brake so quickly as it had done until that point which according to the source is just what some pads are like.

 

So i'll keep the motul for the next fluid change anyway (that's supposed to be once per year when running racing fluids right?)  but the question is, does that glaze layer go away with normal braking/use? certainly felt much improved yesterday but I didn't take a look at the rotors, will do this evening.

 

All in all I guess a stage 2 is too much for standard calipers and rotors on a track.

So i'll keep the motul for the next fluid change anyway (that's supposed to be once per year when running racing fluids right?)  but the question is, does that glaze layer go away with normal braking/use? certainly felt much improved yesterday but I didn't take a look at the rotors, will do this evening.

 

All in all I guess a stage 2 is too much for standard calipers and rotors on a track.

 

Yes you are correct racing brake fluid should be replaced every 12 months if you can. As for the glazing, yes it will go away after a week or 2 from just normal driving. A warning if you are going out doing track days on a regular basis to carry a spare set of brake pads. I have already destroyed 1 EBC Yellow Stuff pad at a event this year and was very lucky to have a spare set of pads to put on and continue on for the rest of the day.

 

In regards to this being mainly a problem for tuned cars (stage 1 and 2). I have had spongy at the end of almost every track day I have done in the Fabia. Even with a stock tune I have still had smoke coming off the brakes. This maybe to do with my driving style or just how far I am willing to push them. In part this is also part of the reason I decided to do a season of hillclimbs as the events are not as had on the brakes. Hopefully I can get my Porsche brakes fitted before next you and then car will be more then capable of beating a few highly rated sports cars. 

Posted this last night on Track action but it doesn't get much attention so since a I had a thread started already I thought I better put it here: 

 

 

Last time at the track I dropped pressures to 30 psi (2bar) all-round prior setting off. Silly me, being there for the first time and getting all excited in the way I forgot to check what the pressures rose to after a few hot laps, but that's how they looked once the day was over (just the fronts) ,they were almost brand new before the track day.

 

 

 

Do the photos above indicate maybe too low/too high a pressure or other worrying situations? Going again tomorrow in 2 hours from now, so any feedback has to be sent before 1pm!

 

 

Judging by the edges being more worn out than the middle of the tyre it looks like slight under-inflation??

 

Cheers

Edited 17 April, 201610 yr by newbie69

you will always wear the edges on track, they look fine to me.... I used to run 2.5 bar all round, and never let them down as they got hot...

Just came back, that was my second time on that track. This time there were more "everyday" cars. Fiesta ST, 2011 Clio RS 197, a few MX-5s (one with a roll-cage in), some old tuned Golf GTI and I think a Chrysler?!  I was expecting some tough competition especially from the 2lt Clio but it wasn't the case. Fabia breezed through them and either the Federals were giving me MUCH confidence on braking or the other drivers were quite conservative. Goal was to improve my best lap from 01:19:503 to, well anything faster than that.  This time I used RaceChrono app together with XGPS160 receiver and what a great combo that is. Being able to see how every change in your driving gives or takes tenths off your lap compared to your best so far is a great tool., it felt like playing Colin McRae almost.

 

First session, little bit of traffic but I pulled off 01:18:400 best and was quite pleased. Second session another 0,7" off (1:17:700) and on the third 1:17 dead which I was excited about, 2,5" off my last visit on such a short track meant I definitely improved my lines. Great fun, although break fading towards the end was such that it made me check the run-off area slightly after the long right-hander past the starting lane, definitely need to do something about the brakes if I keep the car and keep doing track days, stock kit just spoils all the fun after a few laps. Tyres are looking miserable at the moment, even though they have around 8K only   :p

 

Here's a few laps of the 3rd session:

 

Great combo indeed    :$$$: - try next time to place the camera further up - as its trying to focus between dash and track. 

Great combo indeed    :$$$: - try next time to place the camera further up - as its trying to focus between dash and track. 

 

Don't think it's the position but rather the faulty Google camera app on Nexus 6 that tries to focus forever during videos. It's a documented bug and the only work-around is to use an external camera app. Which is fine, but when you have other apps like RaceChrono access the camera, you get the same behaviour... Don't want it too high as the Nexus 6 is big enough to hide half your field of view 

Just came back, that was my second time on that track. This time there were more "everyday" cars. Fiesta ST, 2011 Clio RS 197, a few MX-5s (one with a roll-cage in), some old tuned Golf GTI and I think a Chrysler?! I was expecting some tough competition especially from the 2lt Clio but it wasn't the case. Fabia breezed through them and either the Federals were giving me MUCH confidence on braking or the other drivers were quite conservative. Goal was to improve my best lap from 01:19:503 to, well anything faster than that. This time I used RaceChrono app together with XGPS160 receiver and what a great combo that is. Being able to see how every change in your driving gives or takes tenths off your lap compared to your best so far is a great tool., it felt like playing Colin McRae almost.

First session, little bit of traffic but I pulled off 01:18:400 best and was quite pleased. Second session another 0,7" off (1:17:700) and on the third 1:17 dead which I was excited about, 2,5" off my last visit on such a short track meant I definitely improved my lines. Great fun, although break fading towards the end was such that it made me check the run-off area slightly after the long right-hander past the starting lane, definitely need to do something about the brakes if I keep the car and keep doing track days, stock kit just spoils all the fun after a few laps. Tyres are looking miserable at the moment, even though they have around 8K only [emoji14]

Here's a few laps of the 3rd session:

How do you rate the federals for grip on track and road or would uniroyal be a better choice or some nankang tyres

Sent from my LG-H815 using Tapatalk

How do you rate the federals for grip on track and road or would uniroyal be a better choice or some nankang tyres

Sent from my LG-H815 using Tapatalk

 

As I said to a friend of mine, I was either so much better driver than everybody else that day, or Federals gave me the possibility of braking so much later and pushing so hard in the corners. I think they are amazing for track use (especially considering for how cheap you can buy them compared to bigger track tyre names) and I honestly never had an issue with them on the road. Obviously great on dry but even on rain, I think they grip better than my cheap winters (Nexen Winguard Sport). They've been on for a year now and there hasn't been a single moment that I felt like I've went with an extreme track tyre and ruined some of my everyday driving, which was a thought I had before buying them. If you plan on doing 2-3 track days per year I think they're worth it.

Edited 20 April, 201610 yr by newbie69