Thoughts on (new?) 4 piston Brembo retrofit BBK

[M3MPH1S]

Originally Posted by dparm

I would call Dave at Zeckhausen Racing and ask his advice. Tell him I referred you. He's very knowledgeable and will want to discuss your driving style, tracks you go to, etc. to help pick a pad. He knows BMWs pretty well.

https://www.zeckhausen.com/

I wonder if he'll suggest DTC-60s.

Yep DTC-60

[Visceral]

It'll take me a little while to type all this up, so if I don't have the time in the next 15 minutes I'll finish later. There are some nice systems to be built from various disparate parts, including Brembo calipers, but I'd like to explain why the results vs. a used off-the-shelf BBK are hard to justify.

Things I've determined about our stock braking system:
1. the combination of poor cooling and mediocre rotors is the biggest culprit for brake failure at the track. If you can mitigate one of those two things, you are going to possibly improve the system beyond your performance needs.

2. with the right combination of stainless lines, SRF, and pads, the street "pedal feel" can be as good with the stock brakes as any brake kit on the market. Do NOT buy a BBK for street use unless you have a problem with how the brakes look... in which case you're in the wrong sub-forum.

3. The level of performance where you need to replace the rear brake calipers or rotors is WAY past 99.9% of the cars here. Some people do it for looks, but that just complicates ratios.

So. I learned the hard way that I could build a really good kit out of Slonik Brembo 6p calipers, F80 stock rotors, and the Hard motorsports cooling kit. BUT... what i spent on everything was nearly $2300. For $3000 (or less) there are loads of good used front BBKs with reasonable pad and rotor life left. The trick with used BBKs is to find one with new-ish pads and rotors, otherwise you might as well buy new.

In the end I've got amazing on-track braking. I really enjoy the Ferrodo DS-Uno pads front and Ferrodo 2500 rear. They squeek a little on the street, but the car is barely used on the street.

If you understand braking ratios, how they relate to the tires and suspension (and aero) you use and have some patience, you can create a really great setup using Brembos and F80 rotors for less than other systems. I'm measuring out to use a single set of pads for 5 track days and the rotors look almost brand new. My consumables cost is excellent. And I can source almost any pad out there since I use GT-R or C6 Camaro/CTS-V pads. My brakes are as good as any kit in how they perform... the engine and DCT now have more thermal issues than the brakes. I had to install steering limiters to keep the HardMS cooling kit in one piece, but I havent had any problems with turning radius in 4 months.

Good luck... I was getting catastrophic brake failure the last few laps of a 20 minute session with the stock brakes. You might consider waiting until similar feedback before spending the $$$.

[Visceral]

BTW, once you have excellent feeling and working brakes for your planned track and duration, the only reasosn to buy a fancier front brake kit are:

1. lower consumable cost (unless its a racecar only, in which case you want to avoid dust seals)
2. lighter weight

[M3MPH1S]

Visceral Thanks for taking the time to write that up! Your input is greatly appreciated

[SYT_Shadow]

Not long ago I got to track a student's E92 with PFC DD front rotors and PFC08 pads all around as well as another student's M2 with the stock rotors and PFC08 pads

At no moment did I feel the E92 was under-powered or that the M2's brakes were better. In any way.

I did manage to turn the M2's brakes black after one session though.


People are misguided when they see the simple sliding caliper design of the E92 and think they are worthless on the track. They are perfectly worthy.
Very, very few people on the track 'need' a BBK.


And no, I would not install a $600 'bbk'. No thank you

[dparm]

Originally Posted by SYT_Shadow

People are misguided when they see the simple sliding caliper design of the E92 and think they are worthless on the track. They are perfectly worthy.
Very, very few people on the track 'need' a BBK.

Pad swaps on BBKs are stupid-fast. It took me longer to jack the car up and get the wheel off than it did to swap a pad.

OEM caliper will be slower, but after you do it a few times I'm sure you'll get faster.

[dparm]

Originally Posted by M3MPH1S

Yep DTC-60

Did he agree that you probably weren't getting enough heat into the RS29?

[M3MPH1S]

Originally Posted by dparm

Did he agree that you probably weren't getting enough heat into the RS29?

He said I might be (hard to say) but these would get to temp sooner for sure even if the Pagids were ok. And he said these would be better suited for HPDE use.

[Visceral]

Originally Posted by SYT_Shadow

Not long ago I got to track a student's E92 with PFC DD front rotors and PFC08 pads all around as well as another student's M2 with the stock rotors and PFC08 pads

At no moment did I feel the E92 was under-powered or that the M2's brakes were better. In any way.

I did manage to turn the M2's brakes black after one session though.


People are misguided when they see the simple sliding caliper design of the E92 and think they are worthless on the track. They are perfectly worthy.
Very, very few people on the track 'need' a BBK.


And no, I would not install a $600 'bbk'. No thank you

And we agree on SO MUCH ELSE

You can spend the money on the stock calipers (PFC DD rotors ($1100)) and ventilation (HardMS $600) and sorta make the stock calipers work, but then your consumables goes way up (loads of pads and the occasional $1100 rotors), or you can spend similar money on Slonik Brembos and F80 rotors. I understand you werent cooking brakes, but I drive my own car MUCH more aggressively than I'd drive a student's car. After 20 minutes of late-braking, I routinely put my brake pedal to the floor with stock brakes, and that's not OK (even with runoff).

Choose your aftermarket brake poison, but staying stock isn't a good option.

Even Chris Harris (who owned the 2008 E92 he was reviewing) had no brakes after 20 minutes and made a point to complain about it.

[Visceral]

Originally Posted by dparm

Pad swaps on BBKs are stupid-fast. It took me longer to jack the car up and get the wheel off than it did to swap a pad.

OEM caliper will be slower, but after you do it a few times I'm sure you'll get faster.

Thats a really big difference to me. Because I love DS-Unos (no getting them up to temp or overheating them either), but DS-Unos HATE the street, I do pad changes twice for every track day. With the Brembos, to your point, jacking the car and getting the wheel off takes longer than swapping the pads.

With the stock calipers, that's an extra hour each swap if you are taking your time to re-thread those slide posts carefully.

[dparm]

Originally Posted by M3MPH1S

He said I might be (hard to say) but these would get to temp sooner for sure even if the Pagids were ok. And he said these would be better suited for HPDE use.

Glad to hear he was able to help out. Did you end up ordering a set from him? He stock fluids, too.

[Visceral]

Originally Posted by SYT_Shadow

And no, I would not install a $600 'bbk'. No thank you

Assuming you have to buy a new set of decent pads, there's literally no such thing as a $600 BBK

[M3MPH1S]

Originally Posted by dparm

Glad to hear he was able to help out. Did you end up ordering a set from him? He stock fluids, too.

Didn't order anything yet. Got a friend with connections as well so gonna double check price.

[Ximian]

Originally Posted by dparm

Did he agree that you probably weren't getting enough heat into the RS29?

Isn't it a bit odd that in the same thread we're saying that the brakes are poorly cooled and then that an endurance pad isn't getting enough heat into it?

Are you sure the brake pads are RS29s? Only the RS19 (now known as RSL19) compound is available for stock brakes on the E9x M3s. Some people have reported that the RSL19s are not as effective when they are below 50% wear but I don't entirely believe that. It often sounds like brake rotors and everything else are overheating.

Is the pedal soft for the first 1/4 or 1/3 even when switching to different brake pads?

[M3MPH1S]

Originally Posted by Ximian

Isn't it a bit odd that in the same thread we're saying that the brakes are poorly cooled and then that an endurance pad isn't getting enough heat into it?

Are you sure the brake pads are RS29s? Only the RS19 (now known as RSL19) compound is available for stock brakes on the E9x M3s. Some people have reported that the RSL19s are not as effective when they are below 50% wear but I don't entirely believe that. It often sounds like brake rotors and everything else are overheating.

Is the pedal soft for the first 1/4 or 1/3 even when switching to different brake pads?

Whoops you're right, I was confusing the RS29 rears (which apparently used to be RS19? idk). Yes my fronts are RS19.

Yeah I still have the same trouble when I switch to my street pads (Stoptech street performance - I think those have a new name now)

Yeah like I said, I've never measured temps, but after the first lap or so, they "feel" like they are good. Seems like plenty of bite for my current skill level/tires at least.

[Ximian]

Originally Posted by M3MPH1S

Yeah I still have the same trouble when I switch to my street pads (Stoptech street performance - I think those have a new name now)

Since it's happening with other pads, I would check the brake booster (does it run the expected 5-10 seconds after pumping the brake pedal several times or constantly), double check the lubrication on the caliper guide pins, and triple check the SS lines.

With your mileage and track use, it may be time that the caliper and pistons are either refreshed or retired. For the price compared to replacing OEM calipers, this Brembo kit is a steal. Assuming they do provide the Brembo “Anti-Counterfeiting Card” so you can verify there isn't anything shady going on.

If the choice was between this kit and OEM and the performance of this kit is about even with the OEM brakes, why wouldn't you switch?

[M3MPH1S]

Originally Posted by Ximian

Since it's happening with other pads, I would check the brake booster (does it run the expected 5-10 seconds after pumping the brake pedal several times or constantly), double check the lubrication on the caliper guide pins, and triple check the SS lines.

With your mileage and track use, it may be time that the caliper and pistons are either refreshed or retired. For the price compared to replacing OEM calipers, this Brembo kit is a steal. Assuming they do provide the Brembo “Anti-Counterfeiting Card” so you can verify there isn't anything shady going on.

If the choice was between this kit and OEM and the performance of this kit is about even with the OEM brakes, why wouldn't you switch?

Well yeah that was basically my question. I just did a terrible job of explaining it in the OP

[dparm]

Originally Posted by Ximian

Isn't it a bit odd that in the same thread we're saying that the brakes are poorly cooled and then that an endurance pad isn't getting enough heat into it?

Are you sure the brake pads are RS29s? Only the RS19 (now known as RSL19) compound is available for stock brakes on the E9x M3s. Some people have reported that the RSL19s are not as effective when they are below 50% wear but I don't entirely believe that. It often sounds like brake rotors and everything else are overheating.

Is the pedal soft for the first 1/4 or 1/3 even when switching to different brake pads?

The RS19 and 29 are very similar pads.

My point still stands. Pads have a sweet spot where they work best, and if you can't generate and sustain enough heat into that pad, it will not work well. You'll go for the brakes and have shitty stopping power, then as it heats up it'll suddenly start slowing the car way too fast. That makes it hard to modulate and doesn't instill confidence. Then, as you get back onto the straight, the pads cool down and fall out of the sweet spot again.

[Z K]

The M3 does not have a brake problem with the stock calipers. All it needs is high temp brake fluid and track pads. Not hybrid street/track - track pads. They'll squeal and probably not work well on the street but they will absolutely work on track.

I've nearly 2 dozen track days on the M3 and the stock brakes hold up great even in 110+ degree weather. Consumables like pads and rotors are relatively inexpensive as well. I will say that I had a brake master cylinder fail on me, causing the pads to drag and ultimately brake failure but I think that has more to do with wear and tear than anything.

BBK is more for looks than anything although a ST40 set up will improve brake modulation due to multi-piston set up.

[Visceral]

Originally Posted by Z K

The M3 does not have a brake problem with the stock calipers. All it needs is high temp brake fluid and track pads.

Oh, OK.

[Visceral]

Originally Posted by dparm

The RS19 and 29 are very similar pads.

My point still stands. Pads have a sweet spot where they work best, and if you can't generate and sustain enough heat into that pad, it will not work well. You'll go for the brakes and have shitty stopping power, then as it heats up it'll suddenly start slowing the car way too fast. That makes it hard to modulate and doesn't instill confidence. Then, as you get back onto the straight, the pads cool down and fall out of the sweet spot again.

Those sound like really sh*tty pads.

[roastbeef]

Originally Posted by Visceral

And we agree on SO MUCH ELSE

You can spend the money on the stock calipers (PFC DD rotors ($1100)) and ventilation (HardMS $600) and sorta make the stock calipers work, but then your consumables goes way up (loads of pads and the occasional $1100 rotors), or you can spend similar money on Slonik Brembos and F80 rotors. I understand you werent cooking brakes, but I drive my own car MUCH more aggressively than I'd drive a student's car. After 20 minutes of late-braking, I routinely put my brake pedal to the floor, and that's not OK (even with runoff).

Choose your aftermarket brake poison, but staying stock isn't a good option.

Even Chris Harris (who owned the 2008 E92 he was reviewing) had no brakes after 20 minutes and made a point to complain about it.

you're getting fade after 20 minutes and spending $2,300 on brakes, and you're still recommending slonik?