BBK Comparison thread: Brembo vs. StopTech vs. AP Racing

[imag]

Originally Posted by Gary_C

This is one of the best posts that I have read on this topic and I really appreciate seeing this type of objective reasoning. I am curious though, why you have been soo quick to discredit the Brembo product from your first post, where it did seem that it was originally an option for you?

Rather than simply sharing my personal opinion about the Brembo product, maybe I can answer specific questions based on your actual concerns. I know that Brembo has the largest name in the braking business, and with that comes a varying degree of opinions, but when it comes to the aftermarket/racing products it is definitely one of (if not THE) top choice out there.

Please, share some questions that you think would be helpful to your search, and may also help other people in a similar situation. I'll do my best to share only relevant, factual, and useful information.

Gary - - - -

Thanks all for the posts. I'm an information junkie, so the more I have, the better I feel about what I end up getting.

To answer your questions, Gary, on my view of Brembo:

1. I'm a bit worried about only a front caliper change. On one hand, my concern is that the stock rear caliper/rotor combination has proven not to be up to our needs. On the other hand, I'd obviously be glad to save the money, and I do realize that the addition of the bigger front brake *should* reduce the load on the rears. I'm not sure where to end up in this whole mix.

2. The OEM brake business definitely devalued the brand in my eyes. It was no doubt a good business decision, and I hear your point that the OEM side made no difference to the aftermarket BBKs, but putting out less-than-stellar OEM brakes definitely tarnished Brembo's image. Maybe that's irrelevant, but it's what prompted my comments. In a world where we are being asked to rely on reputations, things like that matter.

- -

Basically everyone is asking us to trust them. That's fine, but it's different than most industries, where I can really research the products I want to buy. I'm not used to it.

One metric I referred to before that I would like to consider is weight. It obviously cannot be looked at in a vacuum, but it is a relevant data point, as we all realize the benefit of unsprung weight reduction. If each of the main BBKs are probably going to be fade-free for 30 minute sessions, lighter is better. I don't know if anyone has data on caliper/rotor weight for each of the BBKs, but it would be nice to have. Yes, I realize that there are tradeoffs with weight - lighter weight means lower thermal mass, potentially smaller rotors, etc.. My guess is that the AP system wins there.

- -

In general, I admit I was pretty naive when I got the car. I figured the OEM brakes, with their 14" rotors and fixed calipers, would be able to handle moderate track use with a rotor and pad upgrade. Now I'm looking at spending $5K on a system I didn't really want in the first place, so I'm being as anal as possible in an attempt to learn. I now realize most any car will need a BBK for track use, but I guess I just thought that was only true for racing. Right now, I'm having to tiptoe around the brake limits pretty carefully or switch to pads for track days* which is a drag, as I will probably still have problems. If I can get away with a new front caliper, then that's great, but what happens when I get a bit faster and now have to go through all this again...

Anyway, thanks again for all the thoughts. I hope there are forum lurkers that this conversation has also helped in one way or another...

*Yes, I realize that track use may mean switching pads. My goal was to have a car I could drive to the track, run, and drive home without swapping parts or alignment. I'm willing to make compromises like:

- Living with an alignment that causes higher tire wear on the street. I figure the tires are going to get worn out on track anyway. I'll live with the cost of getting tires every 3-6 months to avoid tinkering at the track.
- Using street tires on track. I figure I'm not good enough to need track tires at this point anyway, and swapping wheels just isn't in my goal right now.

I am hoping I can get a brake system where I can drive at 9/10ths with streetable (not street, but not pure race) pads. I'm still in the beginner group, so I have a feeling I'm not fast enough for that to be an issue with a BBK. Feel free to weigh in on whether or not I'm delusional...

[AP - Chris_B]

Originally Posted by imag

I figured the OEM brakes, with their 14" rotors and fixed calipers, would be able to handle moderate track use with a rotor and pad upgrade. Now I'm looking at spending $5K on a system I didn't really want in the first place, so I'm being as anal as possible in an attempt to learn. I now realize most any car will need a BBK for track use, but I guess I just thought that was only true for racing.

Yes, I hear this a lot. Unfortunately, the engineers don't win all the battles. Sometimes the accountants (most of the time, actually) get the last word. You should talk to someone with a Corvette C6 Z06 and see what they think of spending around $70k and getting worse brakes than you have! GM had a better option on the table, but the budget simply didn't allow for it. Some have noticed that the ZR-1 uses entirely different brakes. By the way, this is the #1 reason I have never wanted to work for an OEM road car manufacturer. That and the fact that Michigan has very cold winters and all the tracks close down until spring.

Originally Posted by imag

*Yes, I realize that track use may mean switching pads. My goal was to have a car I could drive to the track, run, and drive home without swapping parts or alignment...
I am hoping I can get a brake system where I can drive at 9/10ths with streetable (not street, but not pure race) pads. I'm still in the beginner group, so I have a feeling I'm not fast enough for that to be an issue with a BBK. Feel free to weigh in on whether or not I'm delusional...

This is exactly what the AP Racing road car brake systems were designed and developed to do. It is also why the pads chosen are good to over 1300°F. If you are one of the few pushing past that temp limit, the only options left are full-on race pads. Of course with an AP BBK, you will have lots of options to choose from.

Chris

[imag]

Originally Posted by AP - Chris_B

Yes, I hear this a lot. Unfortunately, the engineers don't win all the battles. Sometimes the accountants (most of the time, actually) get the last word. You should talk to someone with a Corvette C6 Z06 and see what they think of spending around $70k and getting worse brakes than you have! GM had a better option on the table, but the budget simply didn't allow for it. Some have noticed that the ZR-1 uses entirely different brakes. By the way, this is the #1 reason I have never wanted to work for an OEM road car manufacturer. That and the fact that Michigan has very cold winters and all the tracks close down until spring.


This is exactly what the AP Racing road car brake systems were designed and developed to do. It is also why the pads chosen are good to over 1300°F. If you are one of the few pushing past that temp limit, the only options left are full-on race pads. Of course with an AP BBK, you will have lots of options to choose from.

Chris

Exactly - I am stunned that the Z06 brakes have issues on track. I realize that's partly a result of all that horsepower, but still, I would indeed be pissed if I had to retrofit brakes for a car that was sold as a track monster.

I do feel like part of the issue is all the weight on cars. I was thinking the other day about how the only ~2800 lb sports car left is the Cayman/Boxster, then the Miata and the Exige below 2500. In combination with the horsepower wars of the last 10 years, we've got way more energy to manage than before. It sounds like the next-gen RX7 and Miata will continue the light approach, which is good, because to my mind, 3300 lbs. is just too much for a sports car. Mazda also seems to give decent priority to trackworthiness because they understand their customers; it will be interesting to see where they make the price/performance stopper decision. Mazda does have the odd advantage of low horsepower...

It's good to hear that you feel AP's kit is suited to a dual use scenario on the Z. I was worried that the response would just be, "If you want to track your car with any kind of seriousness, you have to get used to switching pads." The whole payoff for me of a BBK is not having to worry about the brakes any more, other than keeping pads and rotors current. I don't mind putting up with a small amount of noise and any amount of dust; I just don't want to have to bring jacks to the track (yet). Eventually all the track regulars seem to drop down the rabbit hole, which leads ultimately to a trailered car, but I'm trying to stay out of that one as long as possible ;-)

[Gary_C]

Originally Posted by AP - Chris_B

Yes, I hear this a lot. Unfortunately, the engineers don't win all the battles. Sometimes the accountants (most of the time, actually) get the last word. You should talk to someone with a Corvette C6 Z06 and see what they think of spending around $70k and getting worse brakes than you have! GM had a better option on the table, but the budget simply didn't allow for it. Some have noticed that the ZR-1 uses entirely different brakes. By the way, this is the #1 reason I have never wanted to work for an OEM road car manufacturer. That and the fact that Michigan has very cold winters and all the tracks close down until spring.

Tell me about it!

Brembo spent a lot of money on proposed development for the C6 ZO6 only to have it left behind in favor for a more price conscious system to meet the budget set for the final price point of that vehicle. The good news is that this development is what has allowed us to be first to market with more than 6 different brake options for the ZO6.

We were though, able to nail the contract for the ZR1 with out CCM technology.

Chris,
Do you know if AP tried to go after that OEM account as well?

[AP - Chris_B]

Originally Posted by Gary_C

Chris,
Do you know if AP tried to go after that OEM account as well?

As far as I can tell, AP Racing spends about zero effort in going after OE accounts from Detroit, although the marketing people at that level don't drop many hints. They do supply GM's Holden HSV programs in Australia, but AP are not really geared for high volume production. It's all been the specialty stuff like the newest cars from Arash, McLaren, Gumpert, Rossion, Lotus, Tramontana, GTA, Caparo, Plethore, etc. These are all low-volume, extreme supercars, not production vehicles like the 'Vette.

[Gary_C]

I hope you're ready for a mini-novel on braking...

Originally Posted by imag

To answer your questions, Gary, on my view of Brembo:

1. I'm a bit worried about only a front caliper change. On one hand, my concern is that the stock rear caliper/rotor combination has proven not to be up to our needs. On the other hand, I'd obviously be glad to save the money, and I do realize that the addition of the bigger front brake *should* reduce the load on the rears. I'm not sure where to end up in this whole mix.

For the caliper upgrade we do only offer the front option.
For the complete big brake systems, we offer front only /or/ front+rear.

The bias is optimized on each of the options by selecting the appropriate piston combination within the caliper. So hopefully knowing that the bias is not negatively affected in any way, you can focus on what is in fact changing and make your selection accordingly. I offer brakes as a solution to an existing problem, or as a preventative step to avoiding future issues. Without knowing the issues you are currently having, or your intent with the vehicle (to avoid potential issues) it's hard for me to tell you where you should end up either.

The caliper upgrade was developed as an intermediate step for aggressive street use and light track duty. The big changes will be in the modulation and control you have over the braking, as well as the longevity of the pads and rotors. You get a much higher quality caliper,... lighter/stiffer, superior design and manufacturing. The calipers improved pedal feel modulation is a direct result of those traits. The pad shape offers improved surface area and volume by almost 40%. The pad also acts as a heat sink, so the larger volume helps to reduce overall temps. The additional life span of the pads and friendliness on the rotor is a positive bi-product of the design.

You do accomplish a whole lot, with very little.
Remember, it's just a caliper, combined with an amazing pad, and a braided line to also assist in pedal feel. We are not increasing the size of the disc, so it's generally not recommended for aggressive track duties, or for drivers already experiencing significant fade related issues. It's designed to make better use of the OEM sized disc.

For the full brake systems, front only /or/ front and rear, we are focusing on the brakes as an entire system and can therefore improve all of the other aspects of braking performance that the OEM system cannot handle. We do increase the diameter of the discs which is the "heart and soul" of temperature management. The larger discs have the ability to absorb and distribute the peak operating temperatures, while at the same time doing a much better job at dissipating this heat and keeping the system operating consistently at MUCH lower temperatures.

The disc is a 2pc. fully floating assembly that provide even pad and rotor wear, reduce the potential for knockback, and seek a true center line for improved modulation and initial bite. Brembo's discs come directly from top level racing and are widely recognized as the best performing, longest lasting, available. Combine that with the impressive traits of our 6-piston monobloc caliper (already discussed above), and you have a system that is virtually bulletproof, and requires the least maintenance and costly consumable items of any other aftermarket brand.

The full systems, front only /or/ front and rear, are developed to prevent any potential brake related issues. The only thing you as a driver need to be concerned with, is finding a pad compound that suits your needs and personal preference. That's it. Our development has taken care of every other aspect.

2. The OEM brake business definitely devalued the brand in my eyes. It was no doubt a good business decision, and I hear your point that the OEM side made no difference to the aftermarket BBKs, but putting out less-than-stellar OEM brakes definitely tarnished Brembo's image. Maybe that's irrelevant, but it's what prompted my comments. In a world where we are being asked to rely on reputations, things like that matter.

In my previous post I made it a point to mention that peoples expectations are a large part of their opinion towards the OEM brake systems. Hands down, the OEM Brembo systems perform above and beyond the capabilities of non-Brembo equipped models. You also need to remember that those of us who are tracking our production vehicles on a regular basis only make up a very small percentage of the total # of vehicles sold. I personally wish that there was a better way to differentiate the capabilities, and potential limitations, of the OEM products vs. those developed for the High Performance division so that peoples expectations would be in line. Unfortunately it's a difficult balance because the capabilities exceed the vast majority of the users expectations, and both Brembo and their OEM partners are more than satisfied with these results. The closest thing to a "one product satisfies all" system is what we offer in the High Performance division, and that level of product even prices itself of of potential for even the $ 6-figure $ vehicles like Ferrari, Aston Martin, Lamborghini, etc...

Basically everyone is asking us to trust them. That's fine, but it's different than most industries, where I can really research the products I want to buy. I'm not used to it.

I think it's really still the same as any other industry, you just have to dig a little deeper to get directly to the source. I generally offer what I feel should be a common sense approach to researching any product, which is to go directly to the source and only listen to what each company has to say about themselves and their own products/capabilities. If one company is talking more about other companies and trying to discredit would be competitors, this should show you that they don't have enough going for themselves to work with.

For Brembo it's a bit difficult because they are a Billion dollar company with multiple divisions. What is the difference between OEM, Racing, and High Performance, and how does one influence the other and vise-versa? Being such a large company you would think their marketing would be on point and information would be readily available at the click of a button. Unfortunately it's not and that has left room for other people to step up and try to position themselves as an authority on the topic.

Brembo is the World Leader in Braking Technology, and is responsible for developing the aftermarket braking industry over the last 10 years. Their High Performance division is the most advanced and most capable on every level. From proprietary software that aids in the selection of components for targeting the optimum brake bias for a given application, to R&D , engineering, and testing procedures that ensure top level performance, their results alone should speak volumes. Brembo's High Performance division is a result of taking the best from OEM and Racing to create a product that exceeds drivers expectations and offers genuine value dollar for dollar.

Too many aftermarket brands function with the mind set that aftermarket products should have a certain "forgiveness" or "compromise" based on what they feel they deliver. Aftermarket products rarely have set standards to which they need to be judged, and creative marketing covers their flaws by turning them into "innovations". Being behind the curtain, I have to laugh sometimes at what is marketing to the public vs. what you are actually receiving. It's not my place to point out other companies flaws, and overtime the truth will expose itself, but I will say that Brembo's customer satisfaction is the best in the industry that I know of.

We stand behind the products 100%, while at the same time we rarely have a reason to do so. Every component in our aftermarket systems go through the same rigorous homoligation process that is mandatory for OE development by every major auto maker, and many of the top level race series. I also don't know of any other aftermarket brands that are subjected to such rigorous testing, in lab and on road, before they are even introduced to the public and eligible for sale.

What I will say about some of the other companies out there, in an effort to support the ones who deserve more respect, is that there are very few companies supplying complete brake systems that are actually manufactures for the products they sell. There's only so much you can do in terms of product development, testing, quality control, even assembly and packaging, when you are not the manufacturer. Brembo owns every step of their process from the mining of the raw materials that make up their cast iron and aluminum, to the final assembly and packaging of the products for delivery to the end user. There's not need for smoke and mirrors or creative marketing when you have total control of the entire process.

One metric I referred to before that I would like to consider is weight. It obviously cannot be looked at in a vacuum, but it is a relevant data point, as we all realize the benefit of unsprung weight reduction. If each of the main BBKs are probably going to be fade-free for 30 minute sessions, lighter is better. I don't know if anyone has data on caliper/rotor weight for each of the BBKs, but it would be nice to have. Yes, I realize that there are tradeoffs with weight - lighter weight means lower thermal mass, potentially smaller rotors, etc.. My guess is that the AP system wins there.

Weight savings is significant with all of our products. I don't have the OEM weights of the 370Z components, but I can provide the weights for each of my components for reference. I don't think Chris would have any problem sharing the AP weights as well. It is a factor that should be relevant, but at the same time form follows function, and unfortunately weight is a factor that's a product of both form and function.

Yes there is a tradeoff,... for example in the friction materials, where my pad shape is significantly larger than OEM (and most other aftermarket options) for functional reasons. Where the pad itself is may be heavier, my caliper will be lighter while being stiffer and more responsive. Our 2pc. rotors are without a doubt lighter than the OEM 1pc. discs, and again offer a functional advantage without the compromise of more weight.

6-piston monobloc caliper =
7.7lbs (w/o pads)
10.8lbs. (with pads)

380mm disc =
17.05lbs. (without hat/bell and hardware)
19.78lbs. (total assembly)

355mm disc = (Brand NEW 370Z option just released during SEMA)
15.43lbs. (without hat/bell and hardware)
17.60lbs. (total assembly)


Questions to ask:

Does the caliper weight include pads?
Some companies intentionally offer weights with or without pads on purpose.

If the weight does include the pads, what is the size, shape and thickness of the pads?
I have seen narrow body, billet calipers that are extremely light, offer impressive caliper clearance, but only come with 10mm thick pads. Yes, the weight is an advantage, but the pad has very little volume for longevity, or to act as a heat barrier for the caliper/fluid.

Does the rotor include the weight of the hat/bell, and mounting hardware?
Brembo uses a very functional hardware that allows for float while remaining noise free. We are still generally lighter than rotor assemblies that are not full floating and simply bolt together.

Side note: All 2pc. rotors are not created equal. Brembo is one of the only companies that provides a 2pc floating rotor that allows for proper radial and axial expansion. Another good hardware is the AP "Strap Drive" system, but not all of the AP kits that are available utilize this setup. Other companies claim to be full floating, but close inspection of their hardware makes it obvious it is not as functional, and their hats/bells become consumable due to the excessive wear. I am only making mention to these variances because weight is one aspect that has MANY contributing factors. It's equally important to find out where the weight is and what it provides in terms of function, longevity and safety.



- -

In general, I admit I was pretty naive when I got the car. I figured the OEM brakes, with their 14" rotors and fixed calipers, would be able to handle moderate track use with a rotor and pad upgrade. Now I'm looking at spending $5K on a system I didn't really want in the first place, so I'm being as anal as possible in an attempt to learn. I now realize most any car will need a BBK for track use, but I guess I just thought that was only true for racing. Right now, I'm having to tiptoe around the brake limits pretty carefully or switch to pads for track days* which is a drag, as I will probably still have problems. If I can get away with a new front caliper, then that's great, but what happens when I get a bit faster and now have to go through all this again...

Different strokes for different folks.
That's why we tend to offer more than one option for the same vehicle.
I do know drivers who have been able to make good use of the OEM brakes based on their driving style and finesse. I know fast/advanced drivers who are brake friendly, and I've seen beginners murder brake systems. Equally, I've seen slow beginner driver who never get enough heat into the system, and fast drivers who heat soak and entire system in 3 laps. I don't make any recommendations until I have sufficient information before hand. I never say BEST, unless it is strictly relevant to the component itself, or the "best" for your personal situation.

The OEM system has decent heat capacity, but very little cooling. When the brakes get hot, they tend to stay hot. The pad shape/size and rotor design are the root of the problem, but there are a few intermediate steps you can take to better the peak performance. You didn't mention improving fluid. You didn't mention braided lines. Both of these options improve fade and pedal feel.

Was your fade mechanical or fluid?
- Mechanical is when the pedal stays hard/firm but you lose friction.
- Fluid fade is when the pedal goes soft and you lose firmness.
You can have both at the same time as well.

Believe it or not, many of the aftermarket rotor options that appear to be upgrades because they are nicely boxed, drilled and/or slotted, with attractive plating and prices, are still the same design but sometimes with a lesser quality/effective metallurgy. A disc of equal size and shape will do nothing for performance unless it is a superior metallurgy and/or an improved vein design (that is actually functional) to improve cooling.

Also, many of the "upgraded" or performance pads that are available actually make the problem worse. If you are exceeding MOT of the OEM pad and inducing mechanical fade, you will need a pad with a higher MOT. At the same time you must pay attention to heat management. Going to a more aggressive pad with a higher operating temperature may help prevent pad fade, but without finding a way to reduce temperatures elsewhere will lead to more problems.

9 times out of 10 the OEM disc that comes on a vehicle is going to be the better quality than aftermarket options. This is due to the fact that OEM products must be homoligated, and meet the QC levels of the automaker. With brakes, there is truth in "you get what you pay for". It may sound cliche, but you can't fake quality when it comes to brake components.
***That's not to say that some dealer products aren't overpriced and you can find equal quality, or even the identical item, elsewhere for less...but when in doubt, throw that option out.***

My approach when you don't want to upgrade to a full system is...
Fluid first, then braided lines, then a properly selected pad upgrade.
If you are still experiencing fade,... recognize the source of the fade and start your plan of attack. Maybe some ducting to get more airflow to the components. Maybe the caliper upgrade with more pad surface area/volume, which comes with the braided line and an amazing pad compound already selected for high performance driving. Maybe you are aware that you have reached the limit of that particular systems design flaws and you step up to a Brembo GT system. In any case you need to have a source to go to for the proper advice along the way.

Anyway, thanks again for all the thoughts. I hope there are forum lurkers that this conversation has also helped in one way or another...

*Yes, I realize that track use may mean switching pads. My goal was to have a car I could drive to the track, run, and drive home without swapping parts or alignment. I'm willing to make compromises like:

- Living with an alignment that causes higher tire wear on the street. I figure the tires are going to get worn out on track anyway. I'll live with the cost of getting tires every 3-6 months to avoid tinkering at the track.
- Using street tires on track. I figure I'm not good enough to need track tires at this point anyway, and swapping wheels just isn't in my goal right now.

I am hoping I can get a brake system where I can drive at 9/10ths with streetable (not street, but not pure race) pads. I'm still in the beginner group, so I have a feeling I'm not fast enough for that to be an issue with a BBK. Feel free to weigh in on whether or not I'm delusional...

You are not delusional at all and I think you are setting your expectations at a more than reasonable level. Your requests are very common and I think what the majority of track day enthusiasts are trying to accomplish. For brakes I don't believe that you have to take the "tradeoff" or deal with compromise. There are dual purpose pads that work well for even advanced/fast drivers who are at the track even more than they are on the street. The Brembo system, by design, is a no compromise solution to performance braking, PERIOD.

You can drive our system across the country with 3 friends and a trunk full of Redbull, just as easily as you can do a dozen track events a year, or compete in a club level race series. With any of the Brembo options, the only thing you will ever have to worry about is finding a pad you like. Replace pads and rotors as they wear, and think of NOTHING else. No rebuilding calipers, no inspecting rotor hats for wear, no safety wire, no seized bolts, no 3rd party QC issues, no "caliper from one company, rotor from another", no cheap pad to keep the initial cost down, no gimmick marketing that doesn't equate to an actual performance benefit, no over promising and underdelivering!

I can point out every single reason that the Brembo system costs what it does, and I can identify every reason why each component was selected and what it offers to the system. If there is a less expensive option, I guarantee I can point out where the cost cutting is taking place so you can make a proper judgment call. Just becuase it's cheaper doen't mean it is not good, and just becuase it is expensive does not mean it is any better.

Brembo was the first company to offer complete aftermarket brake upgrades that were not developed by a third part. They set the standard to which all the others compare themselves, price wise and performance wise. There are other great options out there, and I'm in no way saying that Brembo is the only solution. I just wanted to offer why I think Brembo should be back on your list and I hoped I could offer some insight on why I feel they are a top choice. Thanks for letting me do that.

[AP - Chris_B]

Originally Posted by imag

Basically everyone is asking us to trust them. That's fine, but it's different than most industries, where I can really research the products I want to buy. I'm not used to it.

Me neither. But over the 20 years I've been in this industry I've learned that reputations mean something. They are hard earned and quickly lost. I have also come to understand that I'm buying an experience, not a product. It's a bit like the guy who goes into a home improvement store to buy a drill. He really wants holes, not the drill!

Just because I may reason that one product is slightly better than another, the service after the sale can trump small differences in product offering. All it takes is some bad experiences with a company to undo any perceived product advantage.

Originally Posted by imag

One metric I referred to before that I would like to consider is weight. It obviously cannot be looked at in a vacuum, but it is a relevant data point, as we all realize the benefit of unsprung weight reduction. If each of the main BBKs are probably going to be fade-free for 30 minute sessions, lighter is better. I don't know if anyone has data on caliper/rotor weight for each of the BBKs, but it would be nice to have.

AP5700 (Front 6-piston kit with 362x32mm 2-piece disc) --

Caliper weight, unloaded: 7.3 lb. / 3.31 kg
Caliper weight, loaded w/pads: 10.4 lb / 4.72 kg
Pad area: 72.50 cm^2
Pad thickness: 16.8mm
Rotor weight, assembled: 20.3 lb. / 9.21 kg

Notes: This kit was developed to fit many 18" wheels for those who wish to have a larger selection of track tire compounds. The matching rear kit is strongly recommended for optimum mechanical and thermal brake bias.


AP3750 (Rear 4-piston kit with 330x25.4mm 2-piece disc) --

Caliper weight, unloaded: 4.7 lb. / 2.13 kg
Caliper weight, loaded w/pads: 6.7 lb. / 3.04 kg
Pad area: 48.62 cm^2
Pad thickness: 16.0mm
Rotor weight, assembled: 22.8 lb. / 10.3 kg (iron hat for long-life parking brake function)

Approval and backing by the legendary, record-breaking driver Steve Millen: Included in all AP Racing BBKs at no extra charge!

A note about bolted vs. floating kits. In our experience in designing and building aftermarket upgrade brake systems since 1990, bolted disc assemblies should be used wherever possible. The maintenance-free nature of this type of assembly clearly trumps any advantage of a floating assembly for most users. Only when the thermal capacity of the system is being tested regularly should a floating system be considered.

One drawback of floating systems on street vehicles is lack of proper maintenance. Race teams have a crew of mechanics that perform regular maintenance schedules, which includes an intense amount of brake servicing. For the street, we all just like to bolt them on and forget them. Floating disc assemblies, while definitely having distinct thermal expansion advantages in the upper temperature ranges, tend to collect brake dust, road grime, salt, etc., in between the bobbins and the hat. If cleaned out regularly, this poses few problems. However, most owners aren't up for the extra maintenance (or, more likely, aren't told about it by whoever sold them the kit). But if left to build up, this debris can actually start to prevent the disc from floating -- only now its location is not controlled.

Example: We have seen drivers who have stated their system performs normally when warm, but there is a pronounced steering wheel judder when left overnight. After driving for a bit, thermal expansion of the warmer rotors allowed the parts to become free again. Once hot, parking the vehicle leaves the iron disc just slightly out of plane with respect to the aluminum hat. During cool down, the disc "sticks" in this position due to debris and dust. Once warm again, the disc frees up and all is back to normal.

I am NOT saying this happens all the time with all floating kits! But I am saying it is an issue (like potential rattling sounds) that is entirely prevented when staying with a bolted disc assembly. Talk to anyone with an R35 GT-R who goes over speed bumps or into driveways and hears his car sound like someone bumped into a dishwasher full of large plates. The large discs on that car overpower the float springs and leave drivers sure they have suspension components loosening up!

My rule of thumb: Only go to a floating assembly when it is proven necessary. Several AP Racing systems are sold in a floating arrangement for such applications -- the G's and Z's haven't been two of them. We have done full-floating, dedicated track kits in the past and can continue to do so if the demand is there, but these are not really something most people want to live with on the street. You guys with dedicated track cars -- get in touch with us and we'll work something out. It's a little pricier, but you'll be glad you did.

A better solution? AP Racing's Strap Drive system is the best of both worlds. The disc and hat are free to expand as needed and move slightly relative to each other -- and there are no moving parts to rattle or trap debris. This system is limited in availability at the moment, but could find its way into more kits in 2010. If anyone is interested, that is...

Chris

[ChrisSlicks]

For reference the OEM front rotor is 29 pounds. I haven't weighed the rear, but I'm sure it is similar given only a slightly smaller diameter and have a larger hat.

I'm also interested in what Mike weights the stock calipers in at, when I had them unbolted they felt pretty hefty but I never got to weight them.

All I know is that these Akebono calipers are some of the worse OEM calipers on this class of car I've seen in a long time. They definitely went for the 95th percentile on this one.