DPE

About this time last year I decided I'd look at a Mustang. I posted here asking questions about track-ability and if the car had any particular vices on road courses etc. Finding no significant issues, and with the encouragement of a Mustang-loving wife, we bought a 2010 GT in February. The car has been fantastic, and exceeded my expectations on track; with a few tweaks and appropriate upgrades (see sig), it's just a really nice handling car that simply 'works'. One of those few street cars that you can just go out and drive on track and work on your driving without having to really 'drive around' some inherant flaw. Though lacking in feel compared to a proper sports car (RX-8, etc.), it somehow communicates well enough to be very engaging and not just a fast lump you drive around a track that feels like it would rather be somewhere else (350Z, etc.)

In regard to brakes, the advice I got was XP10s up front, XP8s in back, good fluid (Motul RBF600 in my case), and good brake cooling would make the OEM brakes work fine. I was skeptical, having much experience decimating OEM brakes on a variety of cars, but to my surprise the brakes really DO work well upgraded as suggested. Mostly. Here are my reservations...

(NOTE: I have something around 60 autocrosses, 3500 track miles and a few days at Bondurant under my belt. This does not make me a great driver, but I do run in advanced or instructor level run groups. In other words, the car is being pushed pretty hard.)

1. I've only tried the recommended way, but if I were doing it over I'd run XP10s all around. My reasoning is that after 4 events, my front XP10s are basically shot while my rear XP8s still are in the 40-50% range. By running XP8s on the back, which have a lower friction coefficient, it biases the brakes forward a bit. Clearly they do not need to be biased forward, if the front pads are wearing out well ahead of the rears. However, I'm open to ideas. What was the rationale for running XP10s up front and XP8s rear? Seemed like the consensus was also that if running GT500 Brembos up front, run the same pad all around. Or maybe I read a consensus where there wasn't one.

2. Yes, my front XP10s are basically gone after four events. I will say we also took our annual drive to Arkansas where we encounter some pretty fantastic and pretty deserted twisties, so there's probably 300 miles of very aggressive street driving thrown in as well (yes, I run race pads for that trip; better safe and squeaky than sorry when bombing down a public mountain road). Even so, that's some rapid wear by any standards. I know Carbotechs wear quite a bit faster than Hawks, but this seems excessive. One could say I should run XP12s then, but that begs the question of just how much heat do I want to put into the front end of the car? That, and I never had any fade issues until the last event when the pads were getting very thin, so it may just be that's how fast they're going to wear?

3. Pad wear was somewhat uneven up front. Outer pads wore faster than the inners, and there was a bit of taper as well. Not so much as to be disconcerting, but you could see it. Rotors have the usual surface cracks, but are still smooth in operation.

4. The tracks I run are MAM near Omaha (the flood is finally gone!), HPT in Topeka, and Hallett near Tulsa. Hallett is not particularly hard on brakes, as it's a more 'square' track with no long front straight. MAM is somewhere in the middle, and the front straight at HPT can kill brakes in a hurry; over a rise at 120ish, accelerate a bit more, then brake HARD going downhill from 125or however fast you are going. Only ran HPT once though. If I had run it 3 times, I'll bet it would have killed a new set of XP10s in something less than 250 track miles (roughly 80 miles per event).

Anyway, more just sharing my experiences here and not making any groundbreaking statements, but I think the take-home point is that the OEM brakes do work great on track with the proper upgrades, but if you are a seasoned driver and drive on tracks that are hard on brakes you may want to think about a BBK up front for a long-term solution. I'll likely muddle through another season on OEMs, but after that will go Brembos. Not sure if it'll really solve any pad wear issues, and I could just buy Hawks for something longer-lasting, but my guess is that I'll get more life out of pads and ultimately be putting less heat into things like front wheel bearings and such with a BBK.

Additionally, I've been running on Sumitomo HTRZIIIs in 275/40 (they are cheap and decent; what I needed at the time), and while they are a solid summer tire they're certainly not approaching the grip of a tweener tire like the NT-05 or RT-615 and obviously are far from an R-comp. Run anything more aggressive than the Sumis I had, and that will only make life harder on the braking system. Not to mention I have a stock 4.6L, so my car isn't the fastest Mustang on the block . That's all I've got for today. Glad I joined the Mustang club; it's been a great vehicle thus far.

JAJ

Thanks for the write-up!

My experience on other cars (BMW M5 E39) was similar to yours. Basically, I was blowing through front pads (PFC-01's) and having fluid boiling (RBF600) problems until I switched the rear pads to the same compound as the front. After that, the fluid stopped boiling and I got much better life out of the fronts.

As far as I can tell, uneven pad wear or excessive taper on the same wheel is indicative of running too hot for the pad. Again, the problem at the front should improve with better rear pads.

I'm running a Brembo car and I'm currently using mixed pads (Pagid RS19's front/EBC Yellow rear) and the EBC's are cooked and quite unevenly worn (outer rear pad worn out, the rest at 60 percent) while the Pagid's look like they'll last forever, even with the paint burned completely off. My plan for next year is either PFC-06's or Raybestos ST-47's on BOTH axles, once I've worn the Pagid's out. I was advised to run the same pads front and rear by two folks whose opinions I trust - one is a former professional race driver that runs a 2011 GT500 and the other runs a FR500C. As far as I know, both of them run the Raybestos pads.

Ansibe

DPE, I switched from an M3 to a mustang this year, and I'm thrilled with it. I can hardly believe my $40k mustang can hang with $90k Porsches and M3s and be more fun at the same time.

I'm driving an '11 GT with Brembos and carbotech xp10/xp8, motul fluid and Ford cooling ducts. I did 2 track days with stock pads and no cooling, and 6 with the Carbotech set-up. Tires are (were) the stock PZeros, and I think they're fantastic. My ct pads are still ok.

The brembos discs and pads are big and heavy, so they won't get as hot as the brakes on your '10, but I have 100 more hp, which has the potential to heat them more. One reason my pads are wearing less may be the track I go to - Mosport. the GP track is very fast and isn't hard on brakes. The short track is very hard on brakes, but I limit my sessions to 20 min. The brakes get very hot, but not for too long. I also make sure I cool them gently before stopping. Your inside pad will almost certainly remain hot longer when you're stopped.

My steering wheel vibrates when I'm braking hard and turning slightly. At first I thought it was uneven deposits on the discs, but now I think it may be the ABS. Has anyone else experienced this?

JAJ

Yup. Dunno what causes it, wish it would stop. It seems to come on when the brakes are their hottest. I don't think it's ABS because there's no pedal kick, just the steering wheel.

It might be a function of the pads. It was bad when I was using a street-track crossover pad up front and it improved when I switched to the Pagid endurance race pads. I am hoping that it will go away when I put better pads out back, but I won't know until next year. On an early outing this year, I ran PFC-01's up front and PFC-97's at the back (still have them, only used once) and I don't recall any shaking from the steering. I shelved them because the dust was brutal on the rims, but the braking was great!

Otherwise, the shake doesn't seem to cause any problems, it's just annoying.

Whiskey11

DPE were you at Boo Bash at MAM or just one of the Fast Fridays they had after they opened and before they shut down for the season? I'm hoping there is some money in the budget to go through the MAM orientation class (actually, track orientation class since it counts for Motor Park Hastings out in Hasting NE as well) and attend a Fast Friday at MAM. Right now it's just SCCA Autocross and the MAM track add on and the Saleen/Miller Motorpark FR500S add on on my PC racing sim, Race07.

Nice to hear of someone who runs their S197 at MAM. I can't wait to get out there now that it is open again!

Norm Peterson

If your car has EPAS, it may be an active nibble control feature that is getting confused. Terry Fair has been battling this all year in STX solo, and I think he mentioned there being a TSB out on this for the GT500 with EPAS (but not for the "regular GT's", at least not at the time it was mentioned).


Norm

Ansibe

Norm, thanks. The EPAS makes sense. The car is fine when braking in a straight line, which it wouldn't be if the vibration were caused by deposits. Similarly, when the ABS fires is a straight line the steering is not affected, which doesn't add up if the vibration is caused by the ABS. Plus, when I get vibration while braking and turning, I don't feel the ABS through the pedals. OK, I'm not Jenson Button, but I think I'd notice that!

I will definitely check out the TSBs. The steering vibration drives me nuts, but after dealing with it the whole summer, it no longer slows me down.

JAJ

I get the wobble in straight-line braking, so if it's EPAS, it's happening then too. I'll stick to my "it's the pads" theory until I've proven to myself that it's not.

Argonaut

DPE - happy to hear you are finding the S197 to be such a nice track car. I think the recommendation to use a lower heat range pad in the rear is what you call conventional wisdom. It has been the prevailing school of thought in front engined, rear drivers for years and years and is still the automatic response to the question "what pads should I use". The reasoning is the rear rotors run at a lower temp and thus you need a pad whose optimum friction is generated at a lower temp than the front. But the electronics of modern braking systems have changed and a computer now does much of the work in figuring out how much pressure to apply at each corner. What I'm getting at here is the S197 has a very advanced system that proportions braking balance front to rear and side to side automatically. At least that's what I've read and been told by a number of knowledgable people over the last 4 years. What it means in practice is the car will adapt to whatever pads you put in the back. Some people claim to like equal pads front and rear, while others prefer the old school one step less in the rear. Both work so I don't think it really matters. But I will say this - using front pads at twice the rate of rear is totally normal in my experience.

I like the Carbotech pads a lot. I love their initial bite and overall feel. I also like how streetable and non-corrosive they are. But I don't like how quickly they wear or how fussy they are to bed in. Pros and cons to be sure. I tried the XP12 once and didn't like them at all. Don't assume that the "12" means they will last longer. I certainly didn't find that to be true.

Its not unusual to get strange pad wear behavior (taper, one side wearing quicker than other) with the stock slide-rail calipers. The taper is likely caused by the caliper flexing and spreading at high temps. The only thing that helps is frequently rotating pads. Or going to a BBK, the pad wear in my AP Racing setup is damn near perfect.

DPE

Thanks for the comments guys.

Whisky - I was there a day before Boo Bash for the Fast Friday. On one hand I'd like to see more folks there just to get them as much money as possible to help rebuild, but I have to admit it was nice to have the track almost to ourselves by late afternoon. Really some great track time to be had doing Fast Fridays; on and off as you please (most of the time), not crowded, and a great track for learning as there's very little to hit if you have an off. Typically we make it up there 3-4 times per year; due to the flood, it was just twice this year. Hope to see you out there!

Argonaut - I've heard that conventional wisdom before, but whether it's due to modern electronics or just bad conventional wisdom it's never worked all that well for me on any car (WRX/STI/RX8 etc.). I will certainly run the same pads all around going forward. Mechanically speaking, most cars tend to be overly biased toward the front in the first place just due to the safety factor, and staggering the pads seems to make this worse. At any rate, lesson learned. Not saying I'm the gospel by any means, but that's my take. What AP kit do you run, and why AP vs. Stoptech or GT500 Brembo? Just curious. Good to know that XP12s don't seem to add longevity; saves me from trying that experiment .

Ansibe and JAJ - Just wanted to say I'm jealous of your extra 100hp. That is all . Would have liked to go 5.0, but between the extra cost, transmission concerns, and my wife not necessarily needing 412hp to drive back and forth to work, the 2010 made more sense. Perhaps a Roush M90 will fix the power defecit one day...