Car survived track day, but brakes did not

M

Markcoopers

Member
So the car survived it's first track day in my hands, but the brakes did not.....which was totally expected. Can I just check though what is the "grumbling" under braking, not judder, but a pretty obvious grumble of complaint from the front brakes :D I assume this to be a sign of just the pads crying enough?

My winter project will be;
Strip and remove callipers
Clean and paint callipers (blue or red if interested)
Fit braided Goodrich lines
Fit pagid RS 4-2 or perhaps CLrc5 pads all round
Flush with Motul 660 or similar fluid

Will measure the discs and may well replace these, but not sure of what to use, just call Euro car parts and ask for CSL disks?

Cheers,
 
I was just reading your post, and the advert at the bottom of the page is for ECP, advertising 30% off brakes when you use the promo code CHILL30 :thumbsup:
 
I would highly recommend Pagid RS29 pads if you have a generous budget.

I used to run my M3 track car with these with standard calipers and they were brilliant with uprated hoses, fluid and Performance Friction discs. I previously tried PF Z rated pads and Ferodo DS2500's and these were a big step up, very little in the way of pad deposits too which is important.
 
Yep seen that and looking into copying that. Just curious though, why not use the air feed that comes into the wheel well from the front air dam already, or were you worried that the wheel will strike this on full lock?

Seems every pad under the sun has been recommended at one time or another, so quite confusing to compare them all. :(
 
Markcoopers said:
Yep seen that and looking into copying that. Just curious though, why not use the air feed that comes into the wheel well from the front air dam already, or were you worried that the wheel will strike this on full lock?
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If you remove the front under tray and look closely at the different possible routes, you will see why I have routed the ducting in the way that I have done. Remember, the front of the car is exposed to air at ambient temperature AND at ram pressure and directing that air to the centre of the brakes is the optimum. :thumbsup:
 
Exdos's solution would work well, I'll be doing similar if\when the Z4M gets near a track.

For some more inspiration, here's a duct I made for my M3 track car.

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I'm very hard on brakes - for some reason I expect my 1500kg ///M to decelerate as rapidly as my 500kg Westfield :D I've taken my ///M on many trackdays over the years and I've tried numerous different pads and I've found EBC Bluestuff to be the best value high performance pads. They work well from cold and perform very reliably without fade or overheating (although you will need to use a higher specification fluid). I've had no problems even on tracks with fast straights and slow, tight corners where previously I've melted the friction face of a set of EBC Yellowstuff pads!
Out of interest did you switch off the ESP? If you didn't, it's likely that you cooked the brakes in part though the oversensitive ESP applying brakes through the corners. I've had the pads smoking on all four wheels after only three 'gentle' siting laps by not disengaging the ESP, yet completed the remainder of the trackday without any overheating issues after switching it off. Also, make sure you down a cooling down lap or two after each session without touching the pedal if you can.
The rumbling is likely from the cross-drilled discs - mine tend to rumble a little when hot and quite a lot on track days.
 
500kg westie, nice. I eventually got mine down to 530kgs fully wet with me in it but it was no longer a sensible road car. :D
Funny though as I found myself driving the z4M like the westie, picking up the throttle very early before the apex. In the westie the front was already turned in and hooked up and the weight transfer backwards was just helping traction and away we went all hooked up. In the Z4 it just induced under steer and I found myself slower. Took about 20 mins to realise that it was not a Westie and that turning in with the weight forward and using the engine to load the front tyres (weight) and scrub any more speed off while reaching the apex was the best approach.

Esp on in the damp and greasy morning....off in the afternoon as dry....er.

Funny though, but the sport button remained off as well, the more aggressive map did nothing for the calm inputs needed in the damp greasy moring and in the afternoon foot to floor was required and was quite easy to moderate power with a longer range. Saw 145 on the Bedford get straight.....repeatedly. That probably did for the brakes :D :D :D

Will try blue stuff, braided hoses, better fluid and calmer style.....new tyres as well.
 
I can vouch for Pagid RS29 pads and Motul RBF660 fluid. I'd also be interested in trying some brake cooling but now with the big brake kit it's not necessary.

That grumble you mention should go away after a couple of days of normal driving, it's most likely deposits of the pad material on the disc.
 
Peddle was getting progressively longer through each stint, then would reach a point where the brake effect was noticeable less.....at this point we would do a cool down lap or two and then let it cool for a while. Typically we were 20-30mins a session and like you, similar to various M3's, scoobies, and some other toys.

The grumbling was something we noticed more and more throughout the day.....it did not stop us, just curious as to what it would be.
 
Mushy pedal is a clear sign of fluid boil. The Motul you mentioned will help a lot, especially if you were on stock brake fluid before. Cooling will greatly help as well. :)
 
It can also be pads disintegrating, or the oil leaking. Even seen it as an inverted seal in a master cylinder once as well

I had the M/C seals invert/perish on a Mk2 Scirocco while racing years ago, used the car in front as a brake :? Don't recommend it and got comments on my race licence.
 
Franzino said:
exdos said:
Brake cooling is the most effective way of upgrading brakes. I devised a simple, cheap and effective way of doing this for the Z4M, the details of which can be found here: http://www.z4-forum.com/forum/viewtopic.php?f=24&t=38775
Click to expand...

100% correct… even with my full AP racing kit the extra brake cooling had some really positive effect (on track)… At the picture you can see my extra cooling holes beside the original ones.

z93w.jpg
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I did notice the brake-cooling ducting in that photo in your other thread. :thumbsup: Yep, race cars always use brake cooling, so it must work.
 
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