Time for BBKs?

[mfanatic325]

I know that Z4Ms come with E46 M3 ZCP/CSL brakes as standard equipment from the factory, but to what degree?
Is it just the rotors, pads, and lines? Or are the calipers/carriers also exactly the same?

The reason I ask is because I'm looking to upgrade to BBKs, but am currently still window shopping. Was hoping to find a used E46 M3 set for cheaper or something, but was told that E46 M3 fitment BBKs were different Z4M though

And another thing. Could someone provide a hierarchy of all the major BBKs, starting with the absolute best that money can buy for our cars?
Am I wrong in my research that I should prioritize in this order?
Brembo GTR > StopTech Trophy > AP > Alcon > Brembo GT > StopTech

[ZStig]

I've always wanted to piece together a Wilwood setup, with ultralight calipers

[NickyC]

Originally Posted by Roffle Waffle

I've always wanted to piece together a Wilwood setup, with ultralight calipers

Wilwood? Ugh. I had a Wilwood BBK setup on my 06 GTO, and had nothing but problems. One bad experience does not a company make, but damn, they were horrible.

[The HACK]

The answer is simple, but complicated.

The simple part of the answer is the more expensive the better. Meaning monoblock forged calipers with titanium pistons is going to be significantly better than two piece bolted down cast aluminum calipers with stainless steel pistons. But those are also anywhere from 3-8X more expensive and requires regular rebuild. But you'll NEVER fade a set via fluid boiling nor will you ever have uneven pad wear and the pads will always be in maximum contact with rotors...And the brake will be so responsive that you can feel a millimeter movement in your foot in the brakes. In addition, you can add the fancier Carbon/Ceramic two piece floating rotors vs. cast grey iron one piece rotor.

But do YOU need to spend $10,000-$16,000 for a set of brakes like that? Are you competing professionally where 1/10th of a second means the difference between finishing on the podium consistently vs. middle of the pack, where sponsorship money can be the difference in tens of thousands of dollars?

The complex part of the equation, is in reality, you only need brakes that are good enough for your level of driving. If you're racing professionally in one of the top tier programs, like ALMS or Rolex series, where hundreds of thousands of dollars is the low end of operating expense per season? It makes no sense to buy a low end caliper with a one piece rotor. You'll need the high end Alcon/AP Racing/Brembo competition calipers with accompanying 2 piece floating rotors made of high quality cast grey iron or carbon ceramic. If you're club racing, you may be dictated by who you can get a sponsorship from. The top club racers usually just run whatever or whoever is willing to sponsor them, not always the BEST calipers available unless the "team" is made of money (ever heard of making a small fortune in racing?). If you're doing lapping days? It is very hard to imagine the need to get anything more than the current sliding caliper setup and a good set of rotors and pads, except to look good underneath the wheel. If that is all you're after, it doesn't even really matter which kit you get (as long as you have a quality rotor), as long as your budget allows.

[onelove]

Since our cars came from the factory with the M3 Competition style brakes, you can make up some of the price difference by selling your complete setup to a Standard M3 owner looking to upgrade (I was able to sell mine for close to $1,000 front and rear).

I've been dealing with the majority of the manufactures for over 10 years now, and have to admit in the past 2 years I've put nothing but Stoptechs on my personal and customers vehicles. Ever since Centric purchased them a few years back their quality and R&D has sky rocketed. From a cost standpoint you get an excellent brake package that is balanced for the car at a bargain compared to the comparable competition. The kits use various piston sizing per application to help deal with front/rear brake proportioning eliminating the need for a proportioning valve in most cases.
Are there some benefits to the super expensive Monoblock calipers with Titanium hardware available in the Brembo GTR kits, yes, however if you're not running the Daytona24 or racing professionally you're not likely to see those benefits.

The Stoptech trophy spot kits come from the same exact forgings as the standard calipers, the big difference is that rather than getting powder coated and the logos painted on, the forgings receive an additional cnc process to remove weight and engrave the logo into the caliper, reducing weight by about 15%. They also zinc coat the rotors and provide additional coating on the calipers and rotor caps. They also have STR kits available to compete with the competitions offerings now, which feature titanium pistons and hardware, quick release pins and monoblock offerings, at a cost (and sans dust boots).

If you're not heavily tracking the car, you'll likely be fine with the stock brake setup with a pad upgrade. I can however understand the aesthetic reasons that most upgrade as well. I chose to go with the Stoptech kit on my car for the ease of swapping between track and street pads, and the availability of various pad compounds (the pad shape is the same as some Porsche offerings, meaning most pad companies will have a Stoptech fitment readily available).

[mfanatic325]

Thanks for the input thus far. I think I can narrow it down to either AP Racing's "road" BBK, or the Brembo GTs, or StopTechs; in that order of preference.

For now, I will use up my spare set of OEM pads and/or rotors while first upgrading fluid to ATE Super Blue. I already have StopTech SS lines, but will wait to see if I upgrade to a full BBK or not. Because if I upgrade, then the kit will come with lines, and if I don't need to open and use my current StopTeck line kit, then I'll just sell it as BNIB.

Thus far I've only gotten quotes for new sets of APs and StopTechs, but not yet for the Brembo GTs.

Also, I'm trying to make sure the APs are the ones direct from UK and not the Stillen watered-down ones.

As far as qualifications go, I'm currently running 1:47's @ Laguna Seca (with a shift to 4th and lift-off throttle between turns 5 and 6 to pass sound check; which accounts for maybe a second or two of lap time?) with the mods listed in my signature, on "street" tires (Nitto NT05's). That's approximately 1:45-1:46 absolute fastest I can currently pull off. Since I typically run more consistently in the 1:50's with some traffic during open track days, I know/feel I've got a lot of room to grow still; and since Laguna is killer on brakes and the fact that I've been fading the stock setup for the last 2-3 track days makes me want to consider investing in some good quality entry-level BBKs.

[The HACK]

When I say "level" of driving I mean commitment. As in, are you committed to racing and what level of racing. At the club level not only are you limited by class rules, but you are also likely begging for sponsorship parts and consumables (and if you're not, spending your own money to go racing will get really old really fast). So it doesn't matter that you think you'll be able to churn out laptimes in the X.XX range on Track Y, what brakes you need to run will be dictated by circumstances.

Back on the topics of 'fade'. Big brake kits don't increase the capacity to resist fade, since the M Z4 already cows with one of the most efficient rotor design ever equipped on a BMW. Big brakes with fixed calipers give you consistent pedal feeling with less caliper flex. The ROTORS improve the system's ability to shed heat thus improve fade resistance. The only and proper way to cure fade is improve cooling, not piston count. And since the M Z4 already comes with a massive 2 piece floating rotor you will not gain much in terms of fade resistance from going to a BBK, especially on a relatively light chassis like the M Z4.

Providing proper cooling via a cooling duct will go a much longer way on fade prevention than bigger brakes will on this chassis.

[mfanatic325]

I'm currently only at the level where I can test for SCCA license, but even if I were to get one, I'm pretty sure I won't go into pro racing or anything that dedicated. So my purposes? Mostly for personal pleasure I suppose?

Are you sure about BBK not helping with fade though Hack? Cuz if I were to go BBK the rotors will also be larger, and that in turn is supposed to help with cooling, and therefore prevent fade, no?

[onelove]

Originally Posted by mfanatic325

I'm currently only at the level where I can test for SCCA license, but even if I were to get one, I'm pretty sure I won't go into pro racing or anything that dedicated. So my purposes? Mostly for personal pleasure I suppose?

Are you sure about BBK not helping with fade though Hack? Cuz if I were to go BBK the rotors will also be larger, and that in turn is supposed to help with cooling, and therefore prevent fade, no?

Anyone can test for a SCCA license, it's quite useless without the intent to go racing. Quite honestly it's much better to say "I've got over 30 days of solo track driving" than "could get a SCCA license" IMO.

If you're still using the stock pad setup, I would suggest getting a dedicated track pad setup and go that route first, and then start driving on a real tire at the track. If you're driving the NT05 and not experiencing the tires limits well before brake fade, then you'll definitely want to consider a pad upgrade first on your setup. At that point you should open a new window to lower your times further and test your own limits, then considering dedicated track tires as the next upgrade. I'd be wiling to bet there is a ton more left in reducing your track times than you think.

Food for thought, when I recently upgraded to my BBK my braking capacity was actually REDUCED. The reason... My stock brake setup with Hawk HP+ performed better than the Stoptech BBK with stock/standard pads. It was all in the pad rather than the rotor upgrades. That being said when I put my DTC70 Pads in the Stoptechs for the track, it's a whole nother world of difference. My main reason for the upgrade was exactly that, the ability to swap pads in 10 minutes when putting my track wheels on, and running with Porsche club the ability to find extra pads should I need them at the track was much easier, otherwise I would have stuck with the stock brake setup.

[ZStig]

I wish someone sold a good brake cooling duct for the z4m

[mfanatic325]

hahah and here I was thinking I'd be better off stating SCCA rather than total # of track days.
But anyhow, in terms of total # of track days...I'm tallying only about 16 thus far.
I dunno though....I feel like my 16 doesn't do me justice

[The HACK]

What "onelove" said. I'll add that the TRUE benefit of a fixed caliper big brake comes when you are using high end track pads, because it spreads out the force of the piston and allows for far greater even wear and consistent braking than the sliding caliper design. That's why you need to get BBKs. Typically I throw away my track pads by the time they're worn down to ~50% because they start to show a significant "taper" pattern and is no longer as effective at slowing down consistently.

Another advantage to BBK is weight saving. Aluminum fixed calipers can be anywhere from 1-3 lbs lighter than massive iron sliders. But as far as heat dissipation is concerned the BMW two piece floaters are actually more efficient than your typical BBK rotors, since the actual iron part of the rotor is significantly larger (more surface to shed heat) and the rotor mounting hardware is in the center of the rotor, not the outer face thus allowing more air to enter the cooling vanes.

One more thing I will add. If you are fading the M Z4 brakes with moderately suitable track pads (say, HP+ or better) at Laguna Secca, you are being unnecessarily hard on your brakes and there's more speed to be found from using LESS braking. Laguna Seca is tough on brakes only if you let it be. If you cand do the same 1.4x laps consistently without fading your brakes, you will likely find that dropping another second or two will be very easy.

[onelove]

Originally Posted by The HACK

One more thing I will add. If you are fading the M Z4 brakes with moderately suitable track pads (say, HP+ or better) at Laguna Secca, you are being unnecessarily hard on your brakes and there's more speed to be found from using LESS braking. Laguna Seca is tough on brakes only if you let it be. If you cand do the same 1.4x laps consistently without fading your brakes, you will likely find that dropping another second or two will be very easy.

....and even once you get to the point you're fading HP+, by going to a set of real track tires (NT01 / R6 / etc) you'll further open the window of braking potential by giving the brakes more bite. Swapping to track pads and R compounds will further open up this window.

[mfanatic325]

Okay, plan of action:
1) upgrade fluid first in my stock system
2) use up my spare stock pads/rotors
3) invest in track pads and/or tires
4) invest in AP Racing BBK (the UK version, not the Stillen-tarnished ones)
5) reach ultimate goal of breaking 1:40 @ Laguna Seca

[inTgr8r]

great discussion in this thread!!

mfanatic325; since this started out as a BBK comparo
"Brembo GTR > StopTech Trophy > AP > Alcon > Brembo GT > StopTech"

If you've done some pricing, it would be great to post that as well.
Even if it's just retail #s, it would help to compare.

[Mirko]

I can't add too much to this but I found another option not listed here on Bimmerworld. It is the Performance Friction BBK. I had a Wilwood kit on my 330ci and it was better than stock by 10% for stopping and 50% for fade but I wouldn't get it again.

http://store.bimmerworld.com/perform...kit-p1059.aspx

[mfanatic325]

Thanks for the addition of the PFC BBK. Didn't even know they had one

Originally Posted by inTgr8r

great discussion in this thread!!

mfanatic325; since this started out as a BBK comparo
"Brembo GTR > StopTech Trophy > AP > Alcon > Brembo GT > StopTech"

If you've done some pricing, it would be great to post that as well.
Even if it's just retail #s, it would help to compare.

I have pricing for:

ST60 fronts, ST40 rears --- $5000 (hookup price, tax inclusive, picked up locally)

AP Racing (UK version: non-Stillen) --- $6000 (quasi hookup price, tax-inclusive, picked up locally)

Brembo GT --- $6000+ retail

I didn't bother getting quotes for the StopTech Trophy nor the Brembo GTR, because after I got the quotes above, I was already over my proposed budget LOL!

[inTgr8r]

Thanks....
Good pricing on the Stoptechs!!
That's about the same splits I was seeing as well.

[onelove]

Originally Posted by mfanatic325

Thanks for the addition of the PFC BBK. Didn't even know they had one



I have pricing for:

ST60 fronts, ST40 rears --- $5000 (hookup price, tax inclusive, picked up locally)

AP Racing (UK version: non-Stillen) --- $6000 (quasi hookup price, tax-inclusive, picked up locally)

Brembo GT --- $6000+ retail

I didn't bother getting quotes for the StopTech Trophy nor the Brembo GTR, because after I got the quotes above, I was already over my proposed budget LOL!

StopTech trophy sports add $750/axle so another $1500.

A similar Brembo GTR kit is 10-12k

[mfanatic325]

Good game........
I'll stick with the $5k-$6k playing field. Those are expensive enough for me as is

[Finnegan]

Originally Posted by mfanatic325

Good game........
I'll stick with the $5k-$6k playing field. Those are expensive enough for me as is

No kidding!

Great discussion here, and I for one have learned several things as a developing track junkie. It's good to have a plan and idea of what's required when thinking about plans down the road. Hack, oneLove, thanks!

[CobraR1339]

LS has one braking area that is a bit of a confidence buster, the end of the front straight. For me, there is a confidence lift there in the Z06 when you look at the telemetry. Most novice drivers have the same here.

The Z06 has the same basic caliper set up as on the C5 but the C5 has an inferior rotor. The car will stop and does every time, but lacks confidence. I suspect you have the same issue. There are 2+ secs right here alone. Put a pro in the seat, and it shows a two sec improvement.

I now have Motul, PF01 and brake ducts on the Z06. Better to some degree but more placebo as a Pro friend did not have this advantage. In stock form, he managed 2 secs better here.

The thing Andy Porterfield once said was that, tires really stop the car, not brakes. I seriously doubt you will see sub 1:40 without dedicated tires in the ZM. Not enough HP to do it in that car. You have to carry the speed to do it. Can it be done, sure. But track only tires like a Hoosier will make the most diff. You will find yourself braking 10-20ft later, and on the throttle sooner. That will make the most diff of all.

I seriously suggest you try this first, as you will end up here anyway, you may surprise yourself and save $5k. My best time here on stock tires on a C5 Z06 was 1:44. The new LS Boss with a better driver ( read more seat time at LS ) was 1:42. The Z06 is 3,100lb tops, and 405 Hp. The Boss is 3,700 with 444. The Boss had better tires than the Goodyear Eagle F1, closer to a Nitto. No way the Boss should take the Z06 here with that power to weight ratio, period. All driver and tire.

At ButtonWillow where I have 5 X the seat time. 13CW the Z06 is good for 1:55 with Goodyear real racing slicks, Hoosiers are 1:57 all day, Nittos are 2:00 - 2:01 flat with fresh tires and no heat cycles, Eagle are 2:05-2:06. There is a huge diff in tires.

I have not tried all the tires at LS with the Z06. But, I guarantee you will get more from tires than the stoptechs or others. Would I still like to get them, Yes, are they worth the money, in pure performance, no. Are they worth the money in confidence, possibly. But you will not hit your goal with Stop tech alone IMO.


One other note on the fixed calipers: On the Z06, we tried them and they create pad kick back. This means as you go through a turn the hub flexes enough to kick the pad back. This creates a very weak, soft pedal on the next brake application. You have to pump them up so to speak, or they travel a 1/2 -1.0 inches further. No confidence in that at all. I have no Idea on the Z4. I highly suggest you ask that question and look for REAL hardcore M3 drivers to to get input from. May be a more robust hub on the Z4M, but doubt it. The Vette is pretty strong with the factory Timken bearing. We change them twice a season on the T1 cars.

If the ZM has the same issue you will need an inline pressure system to maintain the pedal. We tested the early C6 stoptech kits and that was a very serious issue. Any BBK would have had the same exact issue without a pressure regulator of some type. With Slicks or Hoosiers the Hub simply will flex enough to cause the issue. What ever you decide, do it right the first time or you you will have a couple very unhappy days till you get it sorted out. Been there, done that.

Best of luck on the 1:38's -1:39's. That will be a stunning time for the Zm at LS. Bring it !.