Brake Biopsy Post-Track Day

Discussion in 'Fiesta ST Road Racing' started by was-an-M, Aug 9, 2014.

  1. was-an-M

    was-an-M Member

    If you read my track day review/comments on my FiST that I posted here you may recall my commenting on the instability under heavy braking and my melting my drivers side front dust boot.

    I got the car aligned to bring it to a total of 1/8" toe out front and rear (down from a fair bit more). At road safe speeds (70 down to 30) the instability seems to have improved.

    However, the brakes were making a terrible noise. Much worse than typical track pad noise which I'm more than a bit familiar with :)

    So since they were only $77 each I decided to replace my calipers figuring the melted dust boots (the passengers side was pretty crispy too) was the cause.

    When I removed the drivers side caliper and inspected the Poterfield R4 pad the attached pictures are what I found.

    I am not sure if the pad was dragging tho the tabs were about the same size as the OE pads and they came out of the carriers without issue. Or if the melted dust boot caused this to happen over the course of the rest of the weekend (I ran 4 20 minute sessions with a melted boot). Anyway, just thought I'd share...check your pads track guys...

    Attached Files:

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  3. reddog99

    reddog99 Active Member

    I assume that the bent pad in photo one isn't supposed to be that way? And from the wear, it's been that way for awhile.
  4. was-an-M

    was-an-M Member

    Certainly not supposed to be that way. As for how long it's been that way for a week. Track use eats pads, especially in this case when it wasn't making contact the way it was designed to.
  5. razorlab

    razorlab Active Member

    Fairly common on single piston systems that are used hard with heat.
  6. raamaudio

    raamaudio Active Member

    Wilwood BBK is the low cost way to seriously track for some of us.
  7. Golfguy11800

    Golfguy11800 Member

    I've tried looking up the suggested Porterfield and Hawk race pads and the aforementioned Wilwood BBK. However, when I search for the product I cannot find any part numbers that match our 2014 Fist's.

    Any one have part numbers for those three items?

    The best brake pads I've ever used were the Pagid RS-29 endurance race pads F/R and Castrol SRF on my 06 Porsche track car. Same pads they use on 12 hours of Sebring and 24 Hours of Nurburgring. The wear rates and friction coefficients are witchcraft.

    I contacted Pagid Racing and they don't plan on making pads for the Fiesta ST, they mainly do Porsche and heavy duty BMW's. However they do make an application for the Euro Ford Focus RS.

    I think the ticket would be to get the
    1. Ford Focus RS calipers and rotors (may need to get a new spindle to accommodate the fit.)
    2. Pagid RS-29's
    3. Castrol SRF
    4. SS lines
    5. More rear brake bias
    6. Higher Spring rates in the front
    7. Larger rear tire width

    5, 6, and 7 should accommodate the the squirliness under heavy braking by transferring load and grip to the rear.

    When I put commuter rear tires on my Cayman (235's) in the rear. The back end wanted to pivot around so fast when heavy braking over 100mph. I normally run 285 RE-11's for track work.

    All in all, still getting used to this FWD "thing" especially when there is no weight over the rear...
  8. razorlab

    razorlab Active Member

    The Wilwood DP6 kit for the Fiesta use a 6712 pad size. Porterfield, Cobalt, Hawk, Carbotech, etc all make brake pads in this size.

    The Wilwood DP6 big brake kit for the Fiesta ST is part #140-11899 and you can find it for under $900 shipped. It's a fantastic value.

    The Pagid RS-29's are comparable to Hawk DTC-30, Carbotech XP8, Porterfield R4's, etc
    Last edited: Aug 9, 2014
  9. raamaudio

    raamaudio Active Member

    Thanks razorlab:)

    I have the BBK here but ordered with GT rotors in 11.75" so have to make custom mounts but that info will be shared with a BBK supplier and be part of a kit, they will just barely fit under my 15x9, 13 lb, $134 roll formed track wheels:)

    I most highly recommend the GT rotors for the fronts.

    I have a rear kit on the way with 4 piston Powerlite calipers with parking brake function(not hill holding capable on steep hills but will do the job when in gear, track day/street car, etc....) and 10.75" vented rotors. I have to make the mounts for them as well but they will become available as a kit.

    They can be ordered with the GT 11" rotor but the mounts would have to be custom and the math dictated the 11's were a bit to big, save .5 lbs per side with the 10.75 which are not GT but very good rotors, cost close to the same price but plenty good enough for the job. The calipers are very lite as well so saving all the weight I can which is always good for real performance.

    Both calipers have plenty of cheap pads available, the rears are only available at one source I know of.

    When finalized I imagine both kits combined with track pads, SS lines, mounts, etc... will run under $2k.

    There is nothing else on the planet I know of for that price, parts availability, reliability, real brakes for real cars, really driven, hard.
  10. was-an-M

    was-an-M Member

    I agree that the Wilwood kit would have been the better option. No doubt it would be better than the stock calipers, but I figured the stock calipers would be ok...

    I bought 15" track wheels so I'm kinda stuck for the time being and since I'm in the middle of building a dedicated track/race car there isn't a ton of sense in buying new track wheels for the FiST for another 2-3 events this season since my race car should be done by next spring.

    Oh well...I went back to the OE pads and we'll see how they hold up in a few weeks at NJMP. I am hoping that if I keep the traction control off it will keep the heat in check and the OE pads will survive. I'll keep everyone posted.

    But yeah, if the FiST were going to be my long-term track weapon I'd have ordered those Wilwoods and new wheels right after I saw that those pads looked like :)
  11. was-an-M

    was-an-M Member

    Wait, will the Wilwood kit fit under 15" wheels? If so maybe I'll order myself a set...
  12. MLKN

    MLKN Active Member

    Crap this thread has me worried. I've done 2 track days on stock pads and can't say I am an expert on what I'm looking at in the pictures.

    The good news is after one of the track days I had the car in for scheduled maintenance and they said everything looked great.

    I'm just hoping I won't have something happen at the next event in September.

    How would I know if I cooked a dust boot?
  13. maybe_fiestast

    maybe_fiestast New Member

    Correct me if I am wrong but the dust boot has nothing to do with brake function right? I read somewhere else that it is just there to protect against corrosion from road salt and such. I know if you go to essexparts for FoST calipers they ship with no dust boots precisely because they melt under track use.
  14. was-an-M

    was-an-M Member

    The dust boots protect long term and really do nothing. It's certainly not a safety issue. I only assumed that was what was causing the noise because I'd never have guessed that I'd bent a brake pad.

    I'm sure you're fine, just do your proper inspections and you'll be ok. I think my issue was caused by leaving the traction control in sport mode and the sticky tires just putting a lot of heat into the brakes.
    ryst likes this.
  15. MLKN

    MLKN Active Member

    I've actually run a few sessions with traction on and didn't notice any problems (except for a single turn when I boiled the break fluid in 105 degree heat).
  16. was-an-M

    was-an-M Member

    I boiled over my motul 600. But I think the R compounds had a lot to do with it.
  17. McRib 1s Back

    McRib 1s Back Well-Known Member

    I'm coming in a bit late on this thread, but I haven't had any of the issues described here. I'd hate to scare people away from good fun with track days! I also believe my FiST has seen appreciably more track time than most cars here. I don't intend that competitively, but as a reference. I often run back-to-back sessions, and have shared my car with a seasoned race car driver (so getting a couple different driving styles going). It runs hot, but has never overheated. My brakes have briefly faded with my current setup, but never completely. This was in brutal desert conditions with ambient around 102 deg F. While I have a spare set of OEM rotors, I'm still on my stock set -- and they look good. It's still just Motul 600, SS lines, Porterfield pads.

    For the questions about pads, please search the forum. We have a well developed thread on the matter. I actually sent in my OEM pads so that Porterfield could make them. Just call them -- they're available in street or race compound, front and back.

    My R compound tires are BFG R1s. I don't know anyone here running something more aggressive. I'm planning to go with something a bit stickier in the near future. Again, just reference for how a stickier tire can affect the other systems.

    The point of my post is an attempt at balance. We have lots of variables, differences in driving technique, and possibly traction control settings. My car is still happy with me, but I do plenty of dumb things, too. From my vantage point, the car is very forgiving and hasn't done anything weird.

    Another thing that occurs to me is that cars straight from the showroom floor have wonky alignment settings. There are lots of reasons for this. One that was common for a while was transportation by rail! One Nissan engineer that I know rigged instruments to see the extreme forces that act on the car and tweak alignment and other stuff.

    This car is my "budget racer" and only sees track time these days. I'll eventually do something more radical with brakes, but for now the only complaint I have is that the brakes are awfully grabby with this setup. Overall braking power is very good, however. Braking feel is very subjective, but I'd give it a score in the lower-middle range. You get used to it.
    RodMoe and BlackBird like this.
  18. was-an-M

    was-an-M Member

    McRib is right on, and my posting this wasn't meant to scare anyone...well it was meant to scare you into always checking your pads, but that's just good sense.

    The car really did well on the track, especially for what it is. I think given the greater amount of track time McRib has on his car compared to me it's fair to say my experience is probably atypical and his is more-so the norm. I can't say what caused my pad/brake issues, but I think we can chalk it up to alignment until further evidence suggests otherwise.

    I may or may not pick up Porterfields for my late season events. I have another event the weekend after next, but there's a family weekend trip and a business trip between now and then so it's doubtful pads are getting swapped. But maybe...

    Rib, what are the compounds they offer? Who do I ask for? And which are the slightly-streetable ones?
  19. McRib 1s Back

    McRib 1s Back Well-Known Member

    The pads swap so easily, I'd encourage you to get them now.

    Anybody there can help you -- it's a normal part of their catalog now. They have both street and race applications. My experience is that even the street pads make noises that are unfun for street use. Both are incredibly dusty, too.

    Here's the thread with details of the journey:
  20. was-an-M

    was-an-M Member

    I could probably actually swap them track side. I'd just like to avoid having to bleed them since my powerbleeder didn't fit.

    How's their turnaround time? When I got the first set I waited about 3 weeks.
  21. McRib 1s Back

    McRib 1s Back Well-Known Member

    It's fast for us here in the SOCAL area -- they're local! I find that they're very good about communicating lead times.

    "R4S" is the street compound.

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