Brake set up opinion needed.

[Krypptic]

I am running a “light weight” m3 that only has leather and ib paint from the factory. Mods list includes intake, akra evo exhaust, dinan pulley and tune and ssk. I have ohlins road and track suspension. BBS FI with ps4 265 up front and 305 in the rear. The brakes are stock except for SRF fluid and pfc street pads.

So... on a 25 minute session, my brake pedal goes to floor. I dialed back the initial brake points but it’s still faded at the end of the session.

My concern is that if I upgrade to a BBK, I will still have the same problem because there is no direct brake cooling that I can see. Before I try and relocate the oil cooler etc to run brake ducts, will the problem be solved by the bbk? Or will the brake ducting make the bbk unnecessary?

Cheers

[Kelse92]

I would try different pads first. Get a track oriented pad setup and try it again. It shouldn’t be that bad especially with SRF fluid. Pads seem like the weak link here to me.

[roastbeef]

Don't mess with the oem coolers to bandaid the shit oem brakes.
A proper bbk with quality race pads will solve this issue.

[Visceral]

I agree that the answer is a front brake kit. I tried full race pads and SRF at one of the two tracks I frequent, it improved, but was still dangerous. I wanted to stick with a lighter set of brakes for AutoX.

I then tried some of the more elaborate cooling options like the HARD setup, and they worked for a short amount of time and then each side disintigrated over two months of track and street use, leaving me $600 lighter but with the brake issues back.

I found the SLON Z07caliper kit to work especially well with F80 rotors. I think total cost was $2500 including my very favorite DS Uno pads. It's heavier, but it just works and the pads are Nissan GTR or Z07 sizes for my application, depending on whether I run the Ti shim, so consumables aren't too bad.

Some people drive in a way that doesnt use as much brakes. I guess I'm hard on them, so that was my experience.

[Krypptic]

Would any of you consider retrofitting the f80 carbon ceramics?

Much better with heat and light weight. Or are they not known to be durable?

[drrust]

Originally Posted by Krypptic

Would any of you consider retrofitting the f80 carbon ceramics?

Much better with heat and light weight. Or are they not known to be durable?

It is my understanding that the ceramic rotors are a high cost item. So if it is a consumable on has to take that into consideration. Also check the classifieds as BBK are often posted there.

[slicer]

Originally Posted by Krypptic

Would any of you consider retrofitting the f80 carbon ceramics?

Much better with heat and light weight. Or are they not known to be durable?

Not light weight and huge which limits you to 19" wheels only - plus no lips on the wheels. Those brakes are the worst I have seen for wheel fitment.

Get a quality kit assembled for the car by Brembo (365/345 - Avoid 380), Stoptech or AP racing. Avoid the Frankenstein retrofit kits from other platforms.

[Richbot]

If it were me, and it was, I would use a Stoptech 355 kit up front and call it good. The STR40 street kit is great, light, not too expensive, will last forever, and on a lighter spec car ought to be fine with pads and fluid. I might also look at just the AP front kit. I wouldn't bother with the rear, though I would recommend doing a slightly spicier rear pad in the OEM rear caliper.

And you don't have to relocate the oil cooler to run brake ducts. Lots of solutions out there, look on the track forum, from as simple as zip tying some 911 GT3 front lower control arm scoops, to as complicated as a GT4 lip with integrated ducts and hoses and backing plate on the front hub, and everything in between. Anything would be better than nothing, a pretty dumb decision by BMW M to stop putting ducting on this generation of M cars. Go take a peek under your GT3 at the plastic thingies that clamp onto the front LCA's

To make a better brake setup unnecessary, the race teams that are limited to stock brakes (or choosing to run them for a weight advantage) are running pretty substantial brake ducting up front that would make the car annoying on the street unless you disconnect it every time. It's totally doable to get the stock brakes through a session with just ducting and a high temp pad, but once you get there you'll start needing to rebuild the stock calipers often, potentially, as the next thing to go will be seals etc. - even with good ducting rotors and pads will wear fast, though you can help that some with some of the upgraded stock-replacement front rotors that are true floaters with more vanes and such

I still think anyone tracking extensively even with a BBK should duct or at least use the 911 scoops, but that's more for longevity of the entire frontend and for lower friction material wear than for whether the thing will just make it through a session without killing you

The other thing is, don't run a street pad on the track not that that would have saved you from fade in this instance, but it sure doesn't help

[W12x]

Originally Posted by Krypptic

Would any of you consider retrofitting the f80 carbon ceramics?

Much better with heat and light weight. Or are they not known to be durable?

The calipers are good, but IIRC I read on the F8 forum the CCB equipped M3/M4 needed to use a different brake booster than non-CCB models, due to the different friction coefficient of the CCB rotors compared to steel.

Getting the F8x's 6 piston front calipers, and matching steel rotors (I believe the M2C uses those), could be a better setup than CCB.

[slicer]

Originally Posted by W12x

The calipers are good, but IIRC I read on the F8 forum the CCB equipped M3/M4 needed to use a different brake booster than non-CCB models, due to the different friction coefficient of the CCB rotors compared to steel.

Getting the F8x's 6 piston front calipers, and matching steel rotors (I believe the M2C uses those), could be a better setup than CCB.

Weighs a ton and horrible wheel fit limitations

[Krypptic]

Decided to try BBK first. Went with stoptech trophies front and rear. I don’t know what’s considered light track Use but 6-8 events a year is where I’m at. I do like to daily the car too so the complicated ducting make not be best. Thanks for the input.

[Kelse92]

Originally Posted by Krypptic

Decided to try BBK first. Went with stoptech trophies front and rear. I don’t know what’s considered light track Use but 6-8 events a year is where I’m at. I do like to daily the car too so the complicated ducting make not be best. Thanks for the input.

Nice choice! Just make sure to get some more aggressive compound pads too with them. The StopTech street pads are great for track, but consider getting a dedicated set of more track-oriented pads to swap out before going to the track too. The bbk’s make the swap really easy.

[M3SQRD]

Originally Posted by Krypptic

Would any of you consider retrofitting the f80 carbon ceramics?

Much better with heat and light weight. Or are they not known to be durable?

No. Not used by people who routinely track their F8x. Switching to the F87 M2C iron rotors reduces cost but each rotor weighs considerably more than the stock (blue) F8x iron rotors. The M2C rotors have the same problem as all M Al cast hat with steel pins - compromised air flow to the rotor vanes.

If you’re pedal is going to the floor then you’re boiling the brake fluid. What brand of brake fluid are you using?

The correct brake kit and race brake fluid will address your braking problems. I’m running the PFC z54/45 setup (unfortunately, discontinued by PFC) on my e92 M3 and the Essex/AP 9668/9449 setup on my f82 M4. PFC brake fluid in both. PFC 11, 05, 03 and 01 pad compounds (11 on the front, other compounds on the rear). Zero braking issues on full weight cars and without additional cooling.

[roastbeef]

Originally Posted by Krypptic

Would any of you consider retrofitting the f80 carbon ceramics?

Much better with heat and light weight. Or are they not known to be durable?

Absolutely not. Heavy and huge. Carbon is also delicate and I've read that if you go off into a gravel pit they are prone to chipping and are worthless.

[Bartledoo]

Surprised you boiled SRF... Wonder if you had air in the system...Before I went bbk, my pfc08 pads would get so hot that my greatest brake force wouldn't stop the car fast enough, but the SRF never boiled.

[Krypptic]

Originally Posted by Bartledoo

Surprised you boiled SRF... Wonder if you had air in the system...Before I went bbk, my pfc08 pads would get so hot that my greatest brake force wouldn't stop the car fast enough, but the SRF never boiled.

Being in south Florida during the summer couldn’t help matters.

[W12x]

Originally Posted by slicer

Weighs a ton and horrible wheel fit limitations

True, but IMO a little better than the CCB still

[roastbeef]

Originally Posted by Bartledoo

Surprised you boiled SRF... Wonder if you had air in the system...Before I went bbk, my pfc08 pads would get so hot that my greatest brake force wouldn't stop the car fast enough, but the SRF never boiled.

I've boiled SRF by taking a set of pads too low.

[slicer]

Originally Posted by W12x

True, but IMO a little better than the CCB still

But really not a good solution period (no matter what rotors you use). There are far better aftermarket options. It's a big disadvantage to be forced to use 19" wheels and they are very heavy. Plus not all 19" even fit

[W12x]

Originally Posted by slicer

But really not a good solution period (no matter what rotors you use). There are far better aftermarket options. It's a big disadvantage to be forced to use 19" wheels and they are very heavy. Plus not all 19" even fit

That, yes.

I have no problem with 19" wheels (don't track the M3 anymore myself), but the wheel fitment, cost/weight of the brake setup, is far from ideal. I have seen folks with M2C going the aftermarket BBK route many times

[Bartledoo]

Originally Posted by roastbeef

I've boiled SRF by taking a set of pads too low.

Damn you guys are beast haha.

[roastbeef]

Originally Posted by Bartledoo

Damn you guys are beast haha.

Not really lol. Just trial, error, and lessons learned.