BBK vs Stock (on-track performance) - data?

[romemmy]

Hi all,

Does anyone have any data that really highlights the difference between the stock brakes and a good BBK setup (Brembo, Stoptech, etc)? I've read a considerable number of posts here on brakes, and all of them pretty much say "<insert brand> BBK is better than OEM", though too often I see it done for looks and/or "gut feel" without any real data. Note that I don't consider major fade/squishiness while running completely stock (i.e. stock fluid, pads, cooling and lines) good data here as any OEM system needs some work to improve - I'm just questioning the lack of faith in the calipers and rotors.

Since I'm not concerned with looks - just on-track performance - I was wondering if anyone has compared a BBK kit with OEM that used track/race pads (not street or semi-street pads), high temp fluid (e.g. Endless RF650, Motul RBF600/660, etc), braided hoses, and upgraded active brake cooling?

The main reason I see cited for upgrading the M3 brakes are around fade or squishiness after multiple laps, though as far as I can see, active cooling, braided lines, high temp track pads, and high temp fluid should solve that all that. That leaves the only real advantage I see to most BBK's - unsprung weight savings.

Thus I'd love to see some data validating all the "you must do BBK upgrade because OEM sucks" opinions. Of course, out of the box, OEM does suck - but right now I don't think that's down to calipers and rotors - just lines, fluid, cooling and pads - all of which can easily be upgraded.

Personally I've run 3 or 4 days (in Advanced groups) in my E90 M3 with just upgraded pads (EBC YellowStuff) and didn't have any real fade issues. My next event will have all the OEM upgrades (fluid, more aggressive pads (OrangeStuff), cooling and lines), and I'm expecting it to improve. However, I'd really like to know if there is a real justification for a BBK (other than weight savings)!

Any insight appreciated!

Thanks!

S.

[roastbeef]

Hi Rome,
The reason you haven't experienced fade is you haven't pushed the brakes hard enough.

Check out this link and scroll down. It's sort of a blog that explains the features of this brake kit. There may be some features you haven't considered.

https://www.essexparts.com/essex-des...p5060355mm-e92

I personally have this kit. Even if you don't want this kit, the information is good to compare to others.

[SYT_Shadow]

OP

I am not at all in this bandwagon of 'oem brakes suck'. I think there is huge disinformation on brakes/suspensions.

Myself and other members have tracked E46Ms for years with just a few upgrades. I switched the rotors to the PFC DD oem replacements that lasted forever and cooled way, way better than stock, plus PFC pads and brake lines and had absolutely zero issues double tracking the car for years

On the E9X, I've seen people with the stock calipers and front PFC DD rotors do the exact same thing.

The PFC DD rotors cool better than stock but most importantly they don't act as cheese graters for your pads. They also take way longer to crack.

On my two E9Xs which I track, I have the PFC BBK. It's just spectacular and rotors and pads for the front last 30-40 track days and the rear lasts 3-4 times longer. However, I have tracked side by side with other cars on stock caliper brakes and have no illusions that BBKs are mandatory

[Dave07997S]

To be honest there isn't that much unsprung weight savings either. I don't think a BBK is going to be needed until you probably move up to slicks or a full R compound tire. Even then the OEM brakes with upgraded pads, fluid and lines can give you really good results.

Dave

[roastbeef]

Originally Posted by Dave07997S

To be honest there isn't that much unsprung weight savings either. I don't think a BBK is going to be needed until you probably move up to slicks or a full R compound tire. Even then the OEM brakes with upgraded pads, fluid and lines can give you really good results.

Dave

The Essex kit gets rid of 22lbs total. That's pretty significant.

[ayao]

On the 1M I found the stock brake setup + track pads was more than adequate. Pad swaps just became tiresome (have to remove the caliper) so I took the plunge with front BBK. I will say that for some inexplicable reason my laptimes dropped significantly (~4 sec) after i installed a BBK ... I have a hard time ascribing this to the brakes but who knows.

[Redd]

With better pads, you can get stock brakes to brake as well as a bbk. However, you'd need to run much more aggressive pads which means higher disc wear.

What you won't be able to do is to get stock brakes to resist fade as well as a bbk. It's all about the heat sink size and that's the size of the rotors. Smaller rotors can't carry as much heat and you will experience fade sooner. It's simple thermodynamics.

Now, as to why you've not experienced fade, well that could depend on the track and your driving style. At Sepang, we face two very long straights one after the other - almost 1km long - and we see speeds in excess of 200kph before braking for a tight hairpin. Trust me, you will see brake fade with stock brakes.

If you're a late braker, that also will induce fade much sooner. I saw fade much later into my sessions just by braking 50m earlier.

[romemmy]

Thanks for all the replies guys!

As for my experience, my first outing with the M3 was at Laguna Seca with stock pads. Big mistake. I cooked the pads within a few sessions and had major fade. Pad material also stuck to the disc and I ended up with a bunch of judder for a while (took a couple weeks for all the stuck material to finally wear down). I wrongly assumed the M3 had decent pads from factory (my Evo, Porsche and Lotus had pretty amazing pads from factory).

I immediately bought new pads. EBC YellowStuff went on, and next event was Sonoma Raceway. Some major braking zones on this track, but as it was just my second day in this particular car, I took it easy somewhat. However, I am familiar with the track so still pushed fairly hard. I can't say I experienced any fade with 25 minute sessions.

I did one more day at Sonoma, then on to Buttonwillow, where the engine exploded so only got half a day out of it.

So all in all 2.5 days of no fade with approximately 25 minute sessions. All sessions (after Laguna) using RE71R rubber, which although not an R-compound, many will say it's pretty darn close (my usual tires are of the R888 variety, though my other cars are lighter than the M3).

I'm not saying that with the new suspension/sways, more practice in this particular car, etc, I won't reach the limit of what I have. That's why for the next outing, which is Laguna - my home track, and one I'm most experienced at - will have the upgraded lines, cooling, and track-specific pads (decided on DTC-70/60 combo instead of the EBC's). Laguna's front straight is pretty intense - corner 1 over the rise is flat through down in to corner 2 - you can easily reach 130mp+ with a quick enough car before you're on the brakes.

I'll report back my findings!

Thanks!

S.

[roastbeef]

Originally Posted by romemmy

Thanks for all the replies guys!

As for my experience, my first outing with the M3 was at Laguna Seca with stock pads. Big mistake. I cooked the pads within a few sessions and had major fade. Pad material also stuck to the disc and I ended up with a bunch of judder for a while (took a couple weeks for all the stuck material to finally wear down). I wrongly assumed the M3 had decent pads from factory (my Evo, Porsche and Lotus had pretty amazing pads from factory).

I immediately bought new pads. EBC YellowStuff went on, and next event was Sonoma Raceway. Some major braking zones on this track, but as it was just my second day in this particular car, I took it easy somewhat. However, I am familiar with the track so still pushed fairly hard. I can't say I experienced any fade with 25 minute sessions.

I did one more day at Sonoma, then on to Buttonwillow, where the engine exploded so only got half a day out of it.

So all in all 2.5 days of no fade with approximately 25 minute sessions. All sessions (after Laguna) using RE71R rubber, which although not an R-compound, many will say it's pretty darn close (my usual tires are of the R888 variety, though my other cars are lighter than the M3).

I'm not saying that with the new suspension/sways, more practice in this particular car, etc, I won't reach the limit of what I have. That's why for the next outing, which is Laguna - my home track, and one I'm most experienced at - will have the upgraded lines, cooling, and track-specific pads (decided on DTC-70/60 combo instead of the EBC's). Laguna's front straight is pretty intense - corner 1 over the rise is flat through down in to corner 2 - you can easily reach 130mp+ with a quick enough car before you're on the brakes.

I'll report back my findings!

Thanks!

S.

when is your next track day, rome? i'll be there 11/18 if you want to go for a ride and feel the brakes from the passenger seat.

[dparm]

Originally Posted by romemmy

I'm not saying that with the new suspension/sways, more practice in this particular car, etc, I won't reach the limit of what I have. That's why for the next outing, which is Laguna - my home track, and one I'm most experienced at - will have the upgraded lines, cooling, and track-specific pads (decided on DTC-70/60 combo instead of the EBC's). Laguna's front straight is pretty intense - corner 1 over the rise is flat through down in to corner 2 - you can easily reach 130mp+ with a quick enough car before you're on the brakes.

The DTC-60s are great pads. You'll be happy with them.

[kyippee]

I've driven both with stock brakes (even pads) and my BBK with street/track pads. Never noticed any significant fade with stock brakes.

However, I recently went to the Laguna Seca where my friend and I did sort of a lead-follow with my friend (with stock braking system and aftermarket pads) in front of me. He had to pull off the track due to brake fade. His brake pedal went to the floor with minimal effect, while I just kept on going and had more capacity available.

If you can find a good deal on a BBK as I did, I figure it's a nice safety upgrade that looks cool while you're at it! Another friend of mine rode along for the last session and told I could still brake harder and later, so maybe I just haven't fully tapped into the BBK capabilities yet.

[romemmy]

Originally Posted by roastbeef

when is your next track day, rome? i'll be there 11/18 if you want to go for a ride and feel the brakes from the passenger seat.

I'm there on both 11/18 and 11/19! Would be great to get a passenger ride for a few laps. What run group are you in?

Thanks!

S.

[romemmy]

Originally Posted by kpewpew

I've driven both with stock brakes (even pads) and my BBK with street/track pads. Never noticed any significant fade with stock brakes.

However, I recently went to the Laguna Seca where my friend and I did sort of a lead-follow with my friend (with stock braking system and aftermarket pads) in front of me. He had to pull off the track due to brake fade. His brake pedal went to the floor with minimal effect, while I just kept on going and had more capacity available.

If you can find a good deal on a BBK as I did, I figure it's a nice safety upgrade that looks cool while you're at it! Another friend of mine rode along for the last session and told I could still brake harder and later, so maybe I just haven't fully tapped into the BBK capabilities yet.

I'm pretty sure was a fluid issue. Fluid upgrade is definitely needed for track work, especially with a 3500lb+ car. Pedal-to-the-floor is the fluid boiling over, which will happen with BBK or stock if the fluid is old, saturated with water, or not rated for a high enough dry/wet boiling point. I don't really consider fluid issues "fade", though some will lump it together. BBK's can delay fluid boil by dissipating heat better, but it will still happen.

Brake fade for me is more about pads being overheated beyond their working range. The pedal won't fall to the floor, but brake efficiency will go out the window making it difficult to stop. That's what the BBK tries to address, though, I think high temp track pads, extra cooling and lines will resolve that too on the stock discs/calipers. BBK's can be overworked too with the wrong pads (e.g. street pads), long track sessions, inadequate cooling, etc. The main thing the BBK adds (from a heat perspective) is extra rotor mass or more efficient rotor cooling vanes, but as a great big heatsink, it will eventually saturate too. Two-piece discs definitely improve temperature performance too.

It will be interesting to see how my stock brakes like my active cooling setup. Hopefully it will help keep rotor temps down.

Thanks!

S.

[romemmy]

Originally Posted by dparm

The DTC-60s are great pads. You'll be happy with them.

I hope so - it's the first time I'm trying this compound. I'm going with the 70's up front and the 60's at the back!

Thanks!

S.

[kyippee]

Originally Posted by romemmy

I'm pretty sure was a fluid issue. Fluid upgrade is definitely needed for track work, especially with a 3500lb+ car. Pedal-to-the-floor is the fluid boiling over, which will happen with BBK or stock if the fluid is old, saturated with water, or not rated for a high enough dry/wet boiling point. I don't really consider fluid issues "fade", though some will lump it together. BBK's can delay fluid boil by dissipating heat better, but it will still happen.

Brake fade for me is more about pads being overheated beyond their working range. The pedal won't fall to the floor, but brake efficiency will go out the window making it difficult to stop. That's what the BBK tries to address, though, I think high temp track pads, extra cooling and lines will resolve that too on the stock discs/calipers. BBK's can be overworked too with the wrong pads (e.g. street pads), long track sessions, inadequate cooling, etc. The main thing the BBK adds (from a heat perspective) is extra rotor mass or more efficient rotor cooling vanes, but as a great big heatsink, it will eventually saturate too. Two-piece discs definitely improve temperature performance too.

It will be interesting to see how my stock brakes like my active cooling setup. Hopefully it will help keep rotor temps down.

Thanks!

S.

Maybe it was. However, I believe he may have already upgraded his fluid and pads - he already swaps on a separate set of wheels/tires for track days. I can ask if you'd like to learn more about the scenario we encountered. I'm personally running the million dollar SRF fluid, so even if he did have aftermarket fluid, it may have had lower heat capacity.

Good luck - report back your findings! Will you be at the Speed SF event at Laguna in 3 weeks? I see one day is still open, may sign up

[romemmy]

Originally Posted by kpewpew

Maybe it was. However, I believe he may have already upgraded his fluid and pads - he already swaps on a separate set of wheels/tires for track days. I can ask if you'd like to learn more about the scenario we encountered. I'm personally running the million dollar SRF fluid, so even if he did have aftermarket fluid, it may have had lower heat capacity.

Good luck - report back your findings! Will you be at the Speed SF event at Laguna in 3 weeks? I see one day is still open, may sign up

Yep - I'm there for both days! I'll be running my M3 on one day (if I can get it put together by then - ran in to some engine build issues today but hopefully still on target), and my Evo on the other day. Let me know if you decide to go.

Thanks!

S.

[kyippee]

Originally Posted by romemmy

Yep - I'm there for both days! I'll be running my M3 on one day (if I can get it put together by then - ran in to some engine build issues today but hopefully still on target), and my Evo on the other day. Let me know if you decide to go.

Thanks!

S.

Awesome, I just signed up for sunday, low intermediate. Let's hang out - I have a bunch of friends with me at Sonoma the weekend before (Sunday as well) but not Laguna!

[roastbeef]

Originally Posted by romemmy

I'm there on both 11/18 and 11/19! Would be great to get a passenger ride for a few laps. What run group are you in?

Thanks!

S.

sweet, i'll be in a space grey e92, number 42. we'll be in a garage with a big blonde german shepherd. come find me.

mike

[kyippee]

Looks like we have a 3-way hang out. Let's connect somehow... not sure if we can do group PM, use whatsapp, telegram, or some other chat app

[roastbeef]

Originally Posted by kpewpew

Looks like we have a 3-way hang out. Let's connect somehow... not sure if we can do group PM, use whatsapp, telegram, or some other chat app

i don't have any of that stuff... lol just come find me and say hi. i'll be at sonoma on sunday.

[romemmy]

Originally Posted by roastbeef

sweet, i'll be in a space grey e92, number 42. we'll be in a garage with a big blonde german shepherd. come find me.

mike

Cool - I only got a garage for the Sunday (by the time I signed up there were no garages left on Saturday!) Not sure which one I'll be in on the Saturday (grey E90 or black Evo), but will be #30 either way! Looks like we're in different run groups if you are the same Mike I'm looking at on the attendee list (I'm advance 2, looks like you are Advance 1) so that's cool.

I'll stop by to say hi!

Thanks!

S.

[romemmy]

Originally Posted by kpewpew

Looks like we have a 3-way hang out. Let's connect somehow... not sure if we can do group PM, use whatsapp, telegram, or some other chat app

Looks like Mike will be there on Saturday, so he won't be there on Sunday! I'll be there though so come find me. I'll have a garage on the Sunday. I have a few people going too, but feel free to find me and hang out! If you wanna PM me your number I do have Whatsapp.

Thanks!

S.