Best BBK for 50% Track 50% Street

[trebm3]

Hey Everyone,
Looking to see what everyone is using on the track in 2025. I've recently turned my E92 to more of a track car vs daily driving and I'm slowly updating everything to be better for the track. Right now I've been cycling through a more aggressive track pad and been cycling between DTC70/60 as well as Pagid pads all on Zimmerman rotors, steel lines and motul brake fluid. This solution works just fine but the sound on streeting driving can be unbearable. FCP has been great with rotor and pad replacement (lifetime warranty).

As I've moved to bigger tracks like COTA and Eagles Canyon (Texas), I've found the want for a BBK and have been looking for something between stock/track pads and official AP or Esses Racing BBK to where I'm not breaking the bank.

I've come across the eBay 18Z solution but I've read they're all chinese copy calipers, rotors and pads and I'd be stuck replacing rotors after half a session and will have to buy track pads right away. Then I'm seeing the M4 conversion as an option but hearing there isn't a big difference on track. Biggest positive here is ease in swapping pads.

What are people's suggestions based on my usage and wanting to save a few pennies?

[Estoril Blue]

What specific problem are you trying to solve?

[Redd]

Anything but Brembo GT kit. Too many fakes, crazy expensive rotors, and random soft pedal issues depending on how unlucky u are. I'd go for Stoptechs and get them from Zeckhausen.

[kolosy]

Originally Posted by Estoril Blue

What specific problem are you trying to solve?

This. Fundamentally, a bbk is about heat management and pad choice. The question of whether it’ll be good for a street/track combo is about pad selection.

[jmeenach]

IMO it's a waste of money to upgrade to F8x calipers.

Also, track pads on stock rotors (which is what the Zimmermans are) will make the rotors heat quickly because they aren't suited well for a harsher pad, especially with longer braking zones. I ran a similar setup and my rotors would get hot QUICK.

For heat management, you can create ducts (many options on here) which can allow you to go longer without going up to a BBK. I would also recommend upgrading to a two-piece rotor setup to replace the OEM rotor. Girodisc still makes a decent replacement setup that I've used, as well as Paragon.

Here is a link to the Girodisc rotor:
https://www.bimmerworld.com/Brakes/B...C7UHysVIxTwRhV

[omgzirra_exe]

GiroDisc 2-piece front rotors with OEM calipers are exactly what you need.

Brake management isn’t just about the brakes themselves. It's also about tires and suspension. The only thing you don’t get with this setup is the ability to flex a big brake kit, and honestly, that’s all it is. Just flex.

F8X retrofits and other conversions are a waste of time and money.

If you really want to do it right, go straight to something like AP 9668, Alcon CR6420, or even Paragon. Otherwise, keep it simple and effective.

I also don't recommend stoptech BBK to anyone since they are not producing any parts for them anymore. so don't bother buying second hand ones.

[trebm3]

Originally Posted by Estoril Blue

What specific problem are you trying to solve?

sorry I thought I mentioned it in my post. Was looking for what people are using and what's worked best from a cost perspective as well as decent performing while still street driving and not wanting to break the bank.

[trebm3]

Originally Posted by Redd

Anything but Brembo GT kit. Too many fakes, crazy expensive rotors, and random soft pedal issues depending on how unlucky u are. I'd go for Stoptechs and get them from Zeckhausen.

that's the issue I keep running into, so many fakes and when I dig further from the seller on a part number or where they've been refurbished they disappear.

[trebm3]

Originally Posted by jmeenach

IMO it's a waste of money to upgrade to F8x calipers.

Also, track pads on stock rotors (which is what the Zimmermans are) will make the rotors heat quickly because they aren't suited well for a harsher pad, especially with longer braking zones. I ran a similar setup and my rotors would get hot QUICK.

For heat management, you can create ducts (many options on here) which can allow you to go longer without going up to a BBK. I would also recommend upgrading to a two-piece rotor setup to replace the OEM rotor. Girodisc still makes a decent replacement setup that I've used, as well as Paragon.

Here is a link to the Girodisc rotor:
https://www.bimmerworld.com/Brakes/B...C7UHysVIxTwRhV

Great info, thanks so much!!!

[M3SQRD]

Originally Posted by omgzirra_exe

GiroDisc 2-piece front rotors with OEM calipers are exactly what you need.

This is definitely one of the better, and more cost effective, options for a car with a 50:50 street-track split. A major advantage is not having to worry about winter use with this setup.

Brake management isn’t just about the brakes themselves. It's also about tires and suspension. The only thing you don’t get with this setup is the ability to flex a big brake kit, and honestly, that’s all it is. Just flex.

F8X retrofits and other conversions are a waste of time and money.

From my experience on student cars, IMO the f8x standard blue retrofit is actually a decent upgrade. You get calipers that make pad swaps easier and larger 380 mm OD front rotors (oem or GiroDisc or Paragon) and 370 mm OD rear rotors (oem or GiroDisc or Paragon). Another advantage, just like e9x M brake setup, is you can use this setup in all seasons without having to worry about protecting inner seals. The f8x 2NK/2NH 6-piston and 4-piston brake setups may be an option on the e9x M if Track/S offers caliper mounting brackets that work with his custom 380 mm OD GiroDisc (and I believe Paragon) front rotors which allows the use of 18” wheels. This would be an excellent option for the e9x M with more capability (fade resistance) than the f8x standard blue brake setup and the ability to run this setup yearly without concern. Only disadvantage is the calipers have to be removed to swap pads.

If you really want to do it right, go straight to something like AP 9668, Alcon CR6420, or even Paragon. Otherwise, keep it simple and effective.

CP9668/CP9449 and CR6420/CAR4949 are the best track options. Paragon PA025 only uses an 18 mm thick pad and I’ve read they have a high pad wear rate. However, you have to pay close attention to, and clean well, the pistons before pushing them back into the caliper. This applies to the track season, especially after a track event with rain, street use, and the winter season. I personally would not use them on the street if the streets have been pre-treated with brine/salt and there’s still salt on the road after an ice/snow storm.

I also don't recommend stoptech BBK to anyone since they are not producing any parts for them anymore. so don't bother buying second hand ones.

I agree. Don’t buy a StopTech brake kit. StopTech has had supply chain issues for at least the past two years and, for a little over a year now, they have stopped supporting kits that use the wide-annulus rotor rings. This forces owners to use custom rotors from Coleman Racing and, potentially, GiroDisc and Paragon (if they already don’t offer replacement StopTech rings for that application).

[Redd]

Good point. Whichever bbk you get, also consider availability/price of consumables like pads and discs.

[jritt@essex]

We have options that lean both towards the street (our Essex Road Brake Kits), and towards the track (our Essex Competition Brake Kits). Even though we technically sell each type of kit for a specific environment, both types are extremely capable in all environments. In reality, we now have thousands of clients running our kits in all types of environments. You can read a short article I wrote on this topic, which outlines our two types of kits:

Which type of AP Racing Brake Kit is Right for Me?

I often refer to our Road Kits as the sledge hammer solution...all the components are extremely large, and they solve heat issues via mass. Conversely, our Competition Kits are the scalpel, shaving all unnecessary weight and solving the heat problem via clever design and material choices. They are both incredibly effective.

Our solutions are not the cheapest, but they are 'buy once, cry once'. Once you have one, you don't have to worry about your brakes again. You can use it until you move on to your next track car. At that point you can sell our kit and recoup about 65% of what you paid for it new, since our kits are such high quality and hold their value extremely well (they are truly an investment). In the meantime you'll save yourself a huge amount of headaches, you won't be perpetually throwing spare pads and discs at your car, and you won't find yourself lying on 120 degree tarmac cursing while bleeding your brakes mid-session.

We have plenty of clients who initially mess around with lesser solutions, but most times they just waste a lot of money and time fooling around with something that doesn't ultimately solve their problems. Then they come to us later and wind up spending even more money than they would have if they had just gotten one of our brake kits in the first place. I've watched this cycle happen 8 million times over my 20+ years in the aftermarket brake business.

As others note, don't underestimate the importance of having a solid provider behind the brake system you choose. Make sure they have a longstanding track record in the industry, that they hold spare parts in stock, and that a live human will answer the phone when you call them. All it takes with a brake system is not being able to get one component from the kit and you essentially have a car on jackstands and a useless pile of metal in your hands. I've watched so many people on this forum get burned by people selling Brembo knockoffs from their mom's basement on the other side of the world. They 'save' some money upfront, but essentially end up with nothing. As a fellow enthusiast, that always makes me steaming mad.

Sorry for the rant.

You can see all options for the e9x M3 here on our site: https://www.essexparts.com/my-vehicl...M3/E90%20Sedan

Feel free to email me if you want more specific advice.

[maddmatth]

I don't get the hate on the F80 brake retrofit in here, likely these guys have never tried it. It's perfect for this use IMO. I've had mine for a while, used on 9 track days so far.
Before installation I had my F80 calipers rebuilt with racingbrakes.com high temp seals and stainless steel pistons, and repainted with high temp paint (because the OEM blue turns black from hard track use).
Paired with Paragon 2 piece rotors and Endless ME20 brake pads.

It handles track use brilliantly. And feels great on street too.

It's probably overkill to put track pads on the rear as it gets nowhere near as hot as the fronts. If you don't want noisy track pads for your street use, then you can just swap the fronts for track days but leave performance pads on the rear.

As a bonus the F80 calipers make for easy pad swaps as the pad slides in and out the back of the caliper, saving you from having to unbolt it.

Also consumables are probably cheaper than other BBKs are it's just takes F80 discs and pads, which have plenty of aftermarket options.

If you are going for more hardcore track use with longer sessions, wheel-to-wheel racing where you need them to handle 30 mins of non-stop fast track time, then maybe you need a proper BBK, but for your general 20 min and under track day sessions or supersprints this will do nicely.

And when you sell the car later you don't need to explain to the new owner where to source some obscure size rotors and pads. Just tell him to look for F80 parts - easy.

[tdott]

Originally Posted by jmeenach

IMO it's a waste of money to upgrade to F8x calipers.

Sounds like your opinion isn't worth much.

F8x retrofit has been a great upgrade for me, it's been 5 years since I've done it. At one point the prices for parts have gone up, but I completed the upgrade for less than you spent on Girodiscs. Prices seem to be coming down a bit now so you can probably get a decent deal.

I've done 30+ track days since then, with about 5 sets of Hawk DTC70 pads, 1 set of Ferodo 1.11, 1 set of Powerstop. I've also had 3 sets of OEM rotors. (FCP FTW), compare how much even 1 replacement set of rings and track pads would cost for a BBK. BBK is definitely a great upgrade and almost a requirement if you are in w2w racing. But the f8x upgrade is more cost effective when it comes to consumables and OEM rotors are easier to get and a set of pads don't cost $800-1000.


So yea let me know what your experience has been.

[M3SQRD]

Originally Posted by tdott

Sounds like your opinion isn't worth much.

F8x retrofit has been a great upgrade for me, it's been 5 years since I've done it. At one point the prices for parts have gone up, but I completed the upgrade for less than you spent on Girodiscs. Prices seem to be coming down a bit now so you can probably get a decent deal.

I've done 30+ track days since then, with about 5 sets of Hawk DTC70 pads, 1 set of Ferodo 1.11, 1 set of Powerstop. I've also had 3 sets of OEM rotors. (FCP FTW), compare how much even 1 replacement set of rings and track pads would cost for a BBK. BBK is definitely a great upgrade and almost a requirement if you are in w2w racing. But the f8x upgrade is more cost effective when it comes to consumables and OEM rotors are easier to get and a set of pads don't cost $800-1000.


So yea let me know what your experience has been.

I agree with you on the f8x brake upgrade. Works well for a large % of people who track their cars.

However, I disagree with your consumable cost of an aftermarket brake kit and the f8x upgrade. I can run ONE set of PFC rotors for 20 track days (5 20 min sessions/day, 3 days/event with 45 min sessions mixed in - more sessions than a typical 4 20 min sessions/day, 2 day/event) + street driving. Similarly, I’ll use ~1.25 sets of PFC pads in 05, 11 or 13 brake compounds over 20 track days + street driving. PFC replacement slotted 372 mm OD front and 355 mm OD rear rotor rings are $525/ring and $400/ring, respectively. The 28 mm thick front and 21 mm thick rear pads cost only $375-625/set and $170-425/set depending on the race compound, respectively. You’ve gone through seven sets of pads and three sets of rotors in only 30 track days (not factoring in FCP Euro warranty). OEM front and rear rotors cost $376/rotor and $354/rotor, respectively. Hawk DTC70 18 mm thick front and 17 mm thick rear pads cost $305 and $265, respectively (Ferodo DS1.11 front and rear are $420 and $413, respectively). Hawk DTC70 pad for PFC Z54 caliper with 28 mm thick pad is only $530. Where are you getting pad costs of $800-1000/set? Is it a complete front and rear sets? OEM Ferodo DS1.11 front and rear pads cost $823 and are only 18 and 17 mm thick pads, respectively. PFC Z54/Z45 thicker pads may initially cost $1050 but for 30 track days the the PFC pad cost is $1969 vs. seven sets of Ferodo DS1.11 pads for the oem calipers that have a total cost of $5831 for 30 track days - equivalent to a minimum of 5.6, or a maximum of 10.7, complete sets of Z54/Z45 PFC pads.

F8x running costs for 30 track days:
Rotors: $4380
Pads: $3990 (Hawk DTC70)
Total: $8370

PFC Z54/Z45 running costs scaled to 30 track days:
Rotors: $1388
Pads: $1969
Total: $3357

For 30 track days, the PFC running costs are 40% of the oem f8x running costs. Track brake kits may have a much higher initial cost but it pays for itself in < 2 track seasons.

[tdott]

Originally Posted by M3SQRD

F8x running costs for 30 track days:
Rotors: $4380
Pads: $3990 (Hawk DTC70)
Total: $8370

PFC Z54/Z45 running costs scaled to 30 track days:
Rotors: $1388
Pads: $1969
Total: $3357

For 30 track days, the PFC running costs are 40% of the oem f8x running costs. Track brake kits may have a much higher initial cost but it pays for itself in < 2 track seasons.

With FCP it's actually:
F8x Rotors + DTC70 Pads = $1692.96 (Front & Rear)
*plus cost of return shipping + any price fluctuations.

PFC isn't a really a good example since you can't buy them anymore new.

AP Racing 9886+9449 = $10,300 + tax (no pads)
DS 3.12 $696.33+$479.17 = $1175.50
Replacement rotor rings $1098 + $1058 = $2156

That doesn't include taxes, shipping or replacement hardware.

But with heavy track use without FCP, it's better to get a BBK I agree there. Most doing the f8x retrofit probably wont be tracking that much, I also don't track my M3 as much anymore, moved to w2w racing with a Spec E9x.

*30 track days was just an estimate, not an actual count.
Also still on the same set of rear rotors, I've only replaced the fronts.

[maddmatth]

Originally Posted by M3SQRD

F8x running costs for 30 track days:
Rotors: $4380
Pads: $3990 (Hawk DTC70)
Total: $8370

PFC Z54/Z45 running costs scaled to 30 track days:
Rotors: $1388
Pads: $1969
Total: $3357

For 30 track days, the PFC running costs are 40% of the oem f8x running costs. Track brake kits may have a much higher initial cost but it pays for itself in < 2 track seasons.

Don't forget though, you can get aftermarket 2 piece discs in F80 (and E90) OEM sizing too. I'm running Paragon rotors and Endless ME20 pads on my F80 brakes. 9 track days and they still have plenty of life in them.

Of course I'm sure the discs won't last as long as BBKs with thicker rotors. I think your use case is still much more track use than the vast majority of us, so for you, it looks like the BBK was worth it.

[M3SQRD]

Originally Posted by maddmatth

Don't forget though, you can get aftermarket 2 piece discs in F80 (and E90) OEM sizing too. I'm running Paragon rotors and Endless ME20 pads on my F80 brakes. 9 track days and they still have plenty of life in them.

Of course I'm sure the discs won't last as long as BBKs with thicker rotors. I think your use case is still much more track use than the vast majority of us, so for you, it looks like the BBK was worth it.

Yes. I know but it wasn’t part of my comparison. I also have three other AP Racing and PFC brake kits I could have included. I think the comparison shows an aftermarket brake kit pays for itself fairly quickly compared to the e9x M “brake upgrade” oem f8x blue stock brake setup. I know how it performs on my f82 until I upgraded to an aftermarket brake kit. 20 days on PFC V3 rotors is the min number of track days it can survive.

[M3SQRD]

Originally Posted by tdott

With FCP it's actually:
F8x Rotors + DTC70 Pads = $1692.96 (Front & Rear)
*plus cost of return shipping + any price fluctuations.

PFC isn't a really a good example since you can't buy them anymore new.

AP Racing 9886+9449 = $10,300 + tax (no pads)
DS 3.12 $696.33+$479.17 = $1175.50
Replacement rotor rings $1098 + $1058 = $2156

That doesn't include taxes, shipping or replacement hardware.

But with heavy track use without FCP, it's better to get a BBK I agree there. Most doing the f8x retrofit probably wont be tracking that much, I also don't track my M3 as much anymore, moved to w2w racing with a Spec E9x.

*30 track days was just an estimate, not an actual count.
Also still on the same set of rear rotors, I've only replaced the fronts.

The same caveats apply (e.g., rear rotor lasts longer than front). I personally would never run any Ferodo pad. 20 days is the low end. Comparison still applies with or without rear rotor replacement at same replacements interval.

AP Racing CP9668 uses a 25 mm thick pad for only a ~$200 difference in price of AP and f8x blue F & R pads but AP lasts much longer so pad cost is higher on the oem f8x blue. AP (or GiroDisc or Paragon) rotors also last longer than f8x blue rotors. I don’t understand how FCP Euro stays in business but you do get inferior rotors for free. You’re also stuck with one track pad with FCP Euro which I stopped using over 20 years ago. Comparing performance instead of cost, AP, Alcon and PFC outperform oem f8x blue.

[tdott]

Originally Posted by M3SQRD

Comparing performance instead of cost, AP, Alcon and PFC outperform oem f8x blue.

No question there! Agree.

I just don't need $10k brakes 😂.

M3 is going back to limited track duty, probably only at events I instruct at or for fun.

[e30gentry]

For a while on our 335d we were tracking we did this and it worked great
Separate rotors for our DTC pads and swapped rotors with oem pads when ever doing longer normal road days.

Upgrading to the two piece rotors and adding some cooler air with nice track pads does wonders if your not going to get full big brake kit.

The F30 and other brembo conversions seem more shoe than anything, they’re going to run into the same issue as the oem brakes.

[bigjae1976]

Originally Posted by M3SQRD

I agree. Don’t buy a StopTech brake kit. StopTech has had supply chain issues for at least the past two years and, for a little over a year now, they have stopped supporting kits that use the wide-annulus rotor rings. This forces owners to use custom rotors from Coleman Racing and, potentially, GiroDisc and Paragon (if they already don’t offer replacement StopTech rings for that application).

Girodisc offers replacement rings. The ass kicker could be the brake rotor hats. Not aware of any alternatives. I don't think any other consumable item is bespoke to Stoptech. Piston seals, dust boots, bleeders, crossover pipes, and hardware. Maybe the abutment plates?

Stoptech is not the best BBK out there but it does have some advantages. The ST40 caliper has an almost unlimited choice of pads. Same pad shape as early Porsche 928/944/968 models. Pad changes are super easy - a big plus if it is a car that sees frequent pad changes.

A 4 wheel BBK with the ST40 caliper front and rear - you can swap pads front to rear in a pinch.

Stay away from the ST60 caliper - it does not have any of the advantages of using Stoptech.