M Coupe Brake Duct Cooling?

[jreifler]

Forgive me if this topic has been addressed elsewhere, but I did a comprehensive search and only found the posts listed below applicable to the Coupe. I'm looking to improve brake performance on track days in my M Coupe, while still preserving "street-ability."

At this point, I'm not upgrading to track pads, but will consider a dedicated set when I run through my current (OEM) pads. I will also eventually upgrade to slotted rotors. In the meantime, I'm upgrading fluid and hopefully adding a Turner Motorsports cooling package before my next track day (2 weekends away). I've ordered the package, but am concerned about rubbing and fitment issues. Just wondering whether anyone else has gone this route and had good or bad experiences.

Thanks in advance for any input.

http://forums.bimmerforums.com/forum...e+duct+cooling

http://forums.bimmerforums.com/forum/showthread.php?1960802-A-Arm-Brake-Cooling-Ducts-for-the-Z3&highlight=brake+duct+cooling

[rich022]

IMO for track DE days, MOTUL 600 brake fluid should be your initial upgrade, then track pads. IMO the front stock brakes are undersized for track use; I'd be interested to see (or hear from guys on the forum) if the cooling ducts remove a lot of the heat. They also look like a pain to install. Track pads: With my stock front brakes I started with Hawk HP Plus and then switched to Pagid Yellows (which are long lasting and easy on the rotors). I found the HP PLUS left deposit on front rotors causing judder. (probably due to my novice braking style). Just my $0.02
I recently switched my stock front calipers/rotors to Stoptech st-40 w 332mm floating rotors (with Apex rims) and saw my rotor temps drop from 450F to 180-200F. happy with the switch albeit an expensive one...

[Bcar]

track pads, or at least high performance street (like a Hawk HP or HP+) are a no brainer. WAY more bang for the buck going with pads than anything else. Takes <10min to swap trackside if you have a jack and electric impact.
the only other thing are SS lines, more of a added margin and feel thing though.

summary: get pads.

[jreifler]

@Rich: Definitely upgrading fluid next week. Not quite ready for the expense of a big brake upgrade yet. Maybe down the road. Appreciate the input though. Incidentally, what Apex wheels are you running? I'm still considering an Arc-8 upgrade. Pics?

@Bcar: I do have a jack and an impact wrench. Is the swap out really that easy? Shamefully never replaced the pads on this car (relatively new to me). Is there no need to bed the new pads first? If it were you, would you return the cooling setup and apply that money (damn near $300) towards pads and possibly slotted rotors?

[FishermanIvan]

I run Euro E36 M3 two piece rotors and Euro M3 pads. Nothing else has changed and it's a champion on the racetrack.

Get pads first. Something. Otherwise, anything you do will be a waste of time.

[BMWBergy]

Cooling packages... a former/infrequent user here, and a very excellent driver and friend, D///Mill, actually installed a brake cooling kit on his coupe many moons ago. He does NOT have a big brake kit, but does use cryo-treated rotors and track compound pads and tires. He is EFFING FAST! BBK is not necessary.

He made a sticker to put on his gauge pod reminding him "1 TURN ONLY" - since, when the ducts are in place, he can only get one full turn of the steering wheel without rubbing/interference/duct disconnection. Obviously, on the track at speed, you will not be turning the wheel that far, but in the paddock or on the street (with the ducts), it's quite likely you will need some similar reminder. The key for normal street driving is to remove the ducting from the fender flange and the rotor flange so that you have max range-of-motion available on the street. Hope that makes sense.

- - - Updated - - -

@Bcar: I do have a jack and an impact wrench. Is the swap out really that easy? Shamefully never replaced the pads on this car (relatively new to me). Is there no need to bed the new pads first? If it were you, would you return the cooling setup and apply that money (damn near $300) towards pads and possibly slotted rotors?

Bcar is right. Pads, pads, pads. I normally opt for overkill. However, in this case, work up incrementally (like my friend D///Mill), starting with pads. Once you are getting very fast on them, think about brake ducts. Once you get very fast on THEM, think about something else for grip, like R-Comps. Take the idea of a BBK, and throw it out.

On bedding in - YES. YES. YES. You absolutely should get the material transfer (bedding in) complete before hitting the track. Takes a little bit of driving, optimally all in one session, but can be broken up over two or three short commutes.

On brake pad install, it is simple. You don't even need an impact tool, unless you need them on the wheel lug bolts or you decide to remove the brake pad carrier from the spindle (NOTE: removal of the brake pad carrier is only necessary for brake rotor removal - can be for brake job or for wheel bearing access - but it is not necessary for pad swap or install). You can remove the caliper guide bolts from the inboard side of the caliper (top and bottom), and back the caliper off. Push the piston back in to the caliper bore (either open the fluid reservoir in the engine bay or the bleed valve only while you are pushing it in), then swap out the pads and reinstall/torque to spec.

How much track time do you have?
A) If you are still on street tires, get Hawk HP+ pads. The HP+ can outbrake my tires when they are at optimal temp.
B) If you are on R-Comps, think about Hawk Blues or something more aggressive. These pads are probably too aggressive for street tires.

[Bcar]

@Bcar: I do have a jack and an impact wrench. Is the swap out really that easy? Shamefully never replaced the pads on this car (relatively new to me). Is there no need to bed the new pads first? If it were you, would you return the cooling setup and apply that money (damn near $300) towards pads and possibly slotted rotors?

not shameful at all! I haven't had to change my pads yet in 18mo... It is very easy to do, I would usually change them a day or two before the event at home (why waste car talk at the track!), and change them back a day or two after. But I know people who do it at the track. Bedding should take <15min. once you change the pads, spray the rotors with some brakeclean (both sides), use a rag or softer green pad to wipe em, let dry and head out for a drive. Gradually warm them up (slight dragging) or do a few medium 40-20 stops, then do some 60-20 stops with ~30sec of cooling between stops, then some harder 60-20s, cool in-between, then hammer them with a few XXX-20 stops with 30-60 sec between stops. Process will vary depending on opinions... you're pretty much taking the pads to a really high temp so the pad material transfers onto the rotor.

I would 100% return the ducts and get pads. Will save some $$ along the way and be "faster"! Fluid first, then pads, then SS lines, then rotors, then R comp tires, then BBK **IF** you find yourself still out driving the brakes at that point. If you think you need more brake after pads/fluid/rotors/lines and you're not on R comp tires, you should work on your driving/braking techniques (unless you're lapping-instructors-fast). PO for my car put on a nice Brembo BBK and ive yet to get the front tires hot enough where ~2/3 pedal force wouldnt put me into ABS...

Honestly, Id hold off on rotors until they need to be replaced, they wont do a whole lot, not worth the $$ IMO until they need replacing.

Good luck!

[jreifler]

Great advice here, guys.
The next DE will be my 3rd in the Coupe, and 5th total. So, I have a TON of learning left to do and massive room for improvement as a driver. That said, in my last event, I had some significant brake fade after several laps, and at points on the track where the lack of instantaneous stopping force was less than confidence-inspiring, to say the least. So, even at this stage, I definitely need some additional stopping power.

I'm running the stock Roadstars with BFG Rivals for track only, and I switch back to 19" HREs for street use. So, I'm already swapping tires for track events, and if the pad change is that easy, it sounds like it would only add another 15-20 minutes to my swapping process (which I usually do the day before an event).

So, consensus is skip the hassle and nonsense of the cooling kit; return it; Hawk HP + and fluid?? I like the plan.

[BMWBergy]

So, consensus is skip the hassle and nonsense of the cooling kit; return it; Hawk HP + and fluid?? I like the plan.

Simply put - yes (not sure on the consensus part, but still... yes).

Fading will cause some serious pucker - not entirely fun. In your case, you simply overwhelmed the stock pads. The brake job is easy, and the HP+ compound/performance characteristics are well-suited to your current hardware (including tires) and experience level.

[rich022]

Yeah, as a beginner start slowly with the investments...As others have noted BBK not necessary, but pads and brake fluid is a must. While we are at it, spend the money and buy a Motive Power Bleeder. This makes bleeding the brakes a charm and NOT a chore.. I'm running 17" APEX...17" minimize $$tire replacement costs... Apex has multiple posts here; you can talk with them. Okay, I just looked up my specs: ARC-8 17.8.5 ET40 Flat... I purposely bought this size that allows a BBK with spacer (in case I was going there which I eventually did). REAR: 17x10 ET 25 concave. in Hyper Black -which is really like a shadow silver. These wheels are wider than stock but weigh less even with tires mounted. My notes show the rear tire+rim are 5 lbs less than stock/each.
Tires I'm running 235 fronts with 15 mm spacer (needed for BBK) and 265 or 275 rears (I'm running 10.5" wide rim, (apex shipped wrong size from my order); I don't recommend as it's hard to find tire choices) I run either Dunlop Star Specs (I believe they are now called Direzza II) or Toyo R1Rs..
Apex Sebring (426x640).jpg