Hi Guys,

I posted this info in the 135i caliper thread over in the 1st gen. section. Seems more appropriate to put it here though. I've got a GP2 with oem brakes. When my last set of stock front pads went, I noticed the bottom of the pads were much more worn than the top. The local dealership told me the lower pistons were sticking and they ended up replacing the calipers completely, under factory warranty. Very awesome. This was back in January. Fast forward a few months; I just finished a weekend at Sebring last weekend and I noticed a slight metal on metal sound from the front passenger side. When I got home and pulled the wheels, I found the pads were worn down completely to backing plate on the underside portion. Meanwhile, the top portion probably had a good quarter inch of material or so so intact. The brake wear sensor was nowhere near touching. All the dust boots of course are pretty well destroyed. I'll also mention, I've just been running oem pads for both street and track use. Reason being, the car came to me with a maintenance package that included all pad, rotor and fluid replacement through 2020. No matter how fast I go through these expendables, Mini has been taking care of it at no cost to me. Again, this is a paid-for maintenance package, not an extended warranty. Furthermore, the delearship has told me to track the car with their blessing..

So I took the car into the dealership on Monday to have it looked at. Heard back from them today that there's nothing wrong with the calipers and they're functioning correctly. I just needed new pads.... Of course this sounded off. I asked to speak with the shop foreman. He assured me that uneven brake pad wear like this was perfectly normal and just due to my "braking style". I mentioned also that it seemed odd to me that the backing plates would be making contact on the lower half while the brake pad wear sensor hasn't come close to making contact. He again said, no, that was typical. He also asked me if those were some aftermarket brakes that I had put on the car... To which I of course responded, that no, they were oem for GP2's.. Why would I be in the dealership getting brake pads replaced on aftermarket brakes... Soooo... that conversation left me very freaked out.

On to a solution. I'm wondering if perhaps the stock pads were just getting so hot that the compound was breaking down and then the pistons basically began applying uneven pressure while the pads were overheating. I don't really know if it's reasonable to assume that the lowest (trailing) piston (or lower pistons) might inevitably have more pushing force in this scenario whereby creating uneven wear... Anyhow, I'm just really curious if any of you might have some insight. I'm at a loss.

I'm going to give Mini USA a call in the morning and see if they can shed some light on it. If it's simply a matter of pad failure due to street pads seeing temperatures that are way too high, no worries, lesson learned. I'm just concerned at the possibility of some sort of piston malfunction. In which case, I obviously want to get that sorted while there's a warranty involved. Regardless, once I've sorted this issue, I'm going to start running some track specific pads and some Motul 600. This is just nuts.

Anyone have some ideas??

Thanks!
Ian

 

 

Thanks for the feedback. Yeah, I'm talking about the leading edge. That makes a lot of sense. It also occurred to me as I've been pondering this predicament, both sides are doing it evenly. Which would further indicate that it's most likely a wear issue and not a malfunction. Looks like the GP's getting some track pads, lol. On a side note, Sebring club course is by far the most brake intensive track I've been on and honestly all things considered, the stock pads worked pretty impressively. I honestly never expected them to handle a single session there. So I just ran with it when they did. I'm really interested now to see how these brakes will be with some proper track pads on them. Just ordered some DTC-30's. Thanks again Eddie

 

 

Yeah I had that thought about the pistons / caliper orientation too. I asked the tech and he said they were on correctly. I also think it's pretty unlikely that two sets of calipers were mounted incorrectly.

As for the pads; I actually totally love Carbos. XP10's are my preferred track pad. Problem is, I won't be able to swap back and forth between stock mini street pads and the Carbos while using the same rotors. I'm defaulting back to that maintenance plan.. As long as I'm getting unconditional free rotor replacement, I can't not take advantage of it. Believe me though, if I still have this car once that plan ends, it'll be XP10's and 1521's all the way. I know it probably sounds silly, most guys who track a lot don't care; I actually really hate how dusty the Hawks are, lol. I like to keep clean wheels, so that's yet another reason why I really like the carbos, lol.

As for the question of DTC-30 or 60; yeah I was totally inclined to agree with you. I've run DTC-60's in a 4 piston wildwood setup on an R56 with really good results. It occurred to me, given the radical increase in pad surface area on the GP brakes, perhaps the DTC-30's might be a better fit. Anyhow, I gave the Hawk guys a call and they said as long as I was on 200 treadwear with those brakes, it would be smarter to be on 30's. So I pulled the trigger on a set. Strangely enough, ECS randomly just had them on sale as limited quantity. Immediate after I purchased, the price went back to normal and inventory went up. Maybe old stock or something. Anyhow, got some decent track pads for $180. Can't beat that. It'll be interesting to see how temps run with them. I'll report the results

 

 

Yeah, I'll report back about the 30's for sure. I'm going to definitely put some Motul in there as well. I have thought about just rolling around on the XP10's... But there again, I'm getting stock pads replaced for free no questions asked, as fast as I can go through them. I just can't get away from utilizing that damn maintenance plan, lol. I know it's not exactly optimal... but.. free stuff. haha

 

 

Next event I'm shooting for is Aug. 31 & Sept. 2 at Sebring. Full course this time Small chance I may do a Track Nights event at PBiR between now and then. Probably not though. Currently contemplating my tire strategy for the rest of the season, lol. I was going to buy two more Federals, but, after closer inspection, it seems super unlikely I'll get the 5 days I was hoping for out of the two decent ones with my plan of sticking them on the back of the car. So I've got a guy who's going to flip all four of them on the wheels for $50. I figure I'll get two days out of them and then it'll be onto the 71's or maaaaybe the Hankook's

I've got some GoPro footage from just the other weekend. I've still got to overlay Harry's on it though, which is such a pita. When I get it done, I'll share a link, if you're interested.

 

 

Hey Eddie,

Apologies for the disappearing act. Been busy busy. Thanks for sharing those videos! Great stuff. Both of those tracks look like such a blast! You're quick too!

I just got the GoPro recently and I haven't quite ironed out syncing it with Harry's. I've had it now for three track days. Man, it's so buggy when connected to Harry's.. I had a couple of really fun sessions early in the day at the last Sebring event, running with a 17' Cayman R on slicks and a 18' Audi TT RS. Side note: man, I was pretty blown away with the TT. I've never been a fan of those cars at all, but, the new RS is heavy on my radar now. That car was incredible on track. He was on Pirelli street tires and nothing more than a light tune. No one got near him. Anyhow, for whatever reason the GoPro didn't record any of the first three sessions Very irratating. It didn't get my 1:18 lap either. It did however record the last session of the day. You can check it out here if you like: I don't have Harry overlay for it, but, thanks to the ridiculous speedo in our cars, you'll get the gist of it, ha! lol. I've also been trying to keep a little video log of changes on the car and progress this year, etc. All but one of the videos are recorded with an iPhone on the dash though, so they're bumpy. But, still kinda cool for checking tracks out =) Here are those if you're interested: https://www.youtube.com/playlist?lis...rO-TS_5DDLKtaC

Back to tires, lol. I flipped the Federal's and I'm going to run them at Sebring (long course) on Sept. 2. I was hoping to do two days but, the price for Aug. 31 is double what sept. 2 is. Blah. Anyhow, I'll definitely get a day out of them. Maybe two. In the meantime, I went ahead and got a set of 71's ordered =) Thanks again for all the helpful info. Hopefully, the GoPro will cooperate at this next event too.

 

 

Thanks for the feedback! That turn at the end of the straight (actually turn 7) is definitely tricky. I completely agree with your assessment of my turn in. It's particularly difficult in that if you heat the brakes too much there, you literally will have nothing available down at the next hard right-hander (turn 10). Coincidentally, when in the club config, turn 10 is turn 1 and turn 7 is turn 9. It's confusing. I'm still no good at knowing the numbers there, lol. I don't even bother with the club numbers, lol. Turn 10 is the only place on the track I've gone 4 straight off multiple times, lol. I've boiled the fluid twice there in the GP. I had a chance to run Sebring Club in my last mini only once with that great Wilwood FSL / XP10 setup and I could brake SO late at turn 7 and then do the same down at 10. It was incredible. My first day running there in the GP, I broke late there and went straight off at 10, lol. Pedal went right to the floor. Nothing. But to be fair, again I've only run in the GP with stock pads and fluid. Which of course is honestly ridiculous. When the track is setup in in that Club course config, the brakes just have no time to cool. Those two places on the track are hands down the sketchiest to get right. Needless to say, I'm excited to head back there with some decent pads and fluid in a couple of weeks. But I tell ya, the track is completely different on the brakes when in the full course config. The long straights between 13 to 15, 16 to 17 and 17 to 1 really give the brakes a chance to cool off. It's an all together different experience. And if the camera cooperates, you'll see, all the really big bumps are down there, lol! Turn 17 is the only place on any track so far that I've ever been genuinely creeped out. It's the highest speed straight into a sharp right-hander there and it's SO tricky to get. It's just weird going by that wall down there because there have been a lot of people who have either died or been seriously injured hitting it. If I'm honest, I prefer running the club course all day long. I'm totally ok not dealing with 17 and 1.

But yeah man, having the GoPro has been cool. it's really shed light on quite a few bad habits I need to work on. It's funny the things you won't overly notice in the heat of the moment. Definitely a good learning tool being able to watch it later. I've noticed I've got an annoying habit of often over-revving in upshifts; there's quite a few places where I need to be using more of the available track at turn-in; obviously turning-in too early in places, I need to choke down on the wheel more; I feel like I often spend too much time with my hand on the shifter and off the wheel; I'm only barely beginning to scratch the surface of heel/toe-ing and rev-matching, the list goes on... So much to learn and master! lol! It's so much fun though. I'm definitely addicted. I did my first event in 2015 and I can't be in the seat enough. I'd go every weekend if I could afford it, lol.

It's funny you mention the tire audible. I actually really like all that noise, lol. I feel like it makes it so much easier to gauge right where the tires are in terms of stepping out and I need all the help I can get! lol. I'm excited to finally try the 71's though. I've only heard awesome things about them from so many people. Anyhow, thanks again for the feedback! I do really appreciate it. You've got a great line at both those tracks. Really smooth and controlled. It would be awesome to ride along with you. Suspect I'd learn a lot! WGI is big time on my bucket list so maybe that'll happen at some point