Comparison test of BBK for the E9x M3 - Surprising results!!!

[Boss330]

German magazine Auto Bild Sportscars did a test of BBK for the E92 M3 in their latest issue (12/2014).

The finishing order was as follows:

1. Stoptech
2. PFC
3. AP Racing
4. BMW original brakes
5. K-Sport (8 pot)
6. Brembo GT kit

The most surprising, to the editors as well, was how bad the Brembo kit did in this test!

From 200km/h - 0 it used 1,9m more than the stock brakes...
From 250km/h - 0 it used 8m more than the stock brakes and a whopping 25m longer than the best BBK!!!

The test was done very meticulously and new Michelin Cup2 tires was fitted for every BBK they tested. And every BBK manufacturers procedures for bedding the brakes was followed to the point.

Each test parametre was tested 20 times (so 200-0 was done 20 times for every BBK).

The test is done with the compounds supplied by the BBK manufacturer and as approved by the TÜV for the kits. Just like what a consumer would get when buying a BBK from the suppliers.

AP Racing and K-Sport both use the Pagid RS29 brake pads.

The test was done at the DEKRA test centre with a independent brake and tuning specialist present.

• With the Brembo they write that the pressure point was inconsistent and after installation and bleeding the brake pedal was very low. After rebleeding the pressure point was still inconsistent and often required a double braking action to restore the pressure point.
  
  
• AP Racing has a very consistent pressure point.
  
  
• The K8 suffered from severe vibrations after some use. It's also heavier than stock brakes.
  
  
• PFC is 10kg lighter than the stock brakes! Has a consistent and short pedal travel as well as being easy to modulate.
  
  
• Stoptech has short and consistent pedal travel and the best modulation. Highest deceleration and no fade.
  
  -

EDIT:

Video posted on their FB page:

https://www.facebook.com/video.php?v=890428987647521

UPDATE 20. january 2015:

In the last issue of Auto Bild Sportscars there was a letter in the "Readers letters" section that took up the BBK test.

The editor replied that they assumed that "Brembo had delivered the wrong kit which was the reason behind the disastrous results" and the they would do a new test with the proper Brembo BBK that would be published later.

[Acree]

Amazing article, but WTB a translator

[MMAJNKE]

yes def need to translate this asap!

[IND-Distribution]

I'm not able to read the article, but a few questions come to mind immediately:

-Did these journalists install the same brake pad compound in each kit? It looks like some kits are using Pagid RS29 pads and others are using a different pad.

-Did these journalists measure any other parameters than stopping distance?


A few things to consider:

-Stopping distance is largely a test of pad compound, and less so a test of the design of the brake caliper or rotor. An excellent compound in the original BMW brakes can produce a very low stopping distance, provided that the tires have enough grip to operate up to the compound's ability.

-Brake calipers and rotors are upgraded to increase their thermal capacity, not their one-time stopping distance. The key is not what the brake system can do once, rather the question is what consistency does the brake system offer over time?

Most E9x M3 owners that drive their cars quickly around the track have noticed that even with an excellent brake pad compound (which does provide better stopping distance), the original BMW E9x M3 brakes will eventually fade and fail with hard use.

This test does not appear to test brake operating temperature over time, nor does it seem to graphically represent performance (brake fade or lack thereof). This test also shows several of the brake kits loaded with Pagid's RS29 pads (an excellent track brake pad), and the other kits loaded with other pads (I am assuming Ferodo FM1000 for the Brembo kit, and stock for the BMW kit).

For an empirical test I would have loaded all of the brake calipers with a high performance pad like the RS29, and logged brake fade in some way.

As-is, even the stopping distance test conducted here is of no use. The data is not accurate due to the inconsistency in pad compound.

[Boss330]

Originally Posted by Ilia@IND

I'm not able to read the article, but a few questions come to mind immediately:

-Did these journalists install the same brake pad compound in each kit? It looks like some kits are using Pagid RS29 pads and others are using a different pad.

-Did these journalists measure any other parameters than stopping distance?


A few things to consider:

-Stopping distance is largely a test of pad compound, and less so a test of the design of the brake caliper or rotor. An excellent compound in the original BMW brakes can produce a very low stopping distance, provided that the tires have enough grip to operate up to the compound's ability.

-Brake calipers and rotors are upgraded to increase their thermal capacity, not their one-time stopping distance. The key is not what the brake system can do once, rather the question is what consistency does the brake system offer over time?

Most E9x M3 owners that drive their cars quickly around the track have noticed that even with an excellent brake pad compound (which does provide better stopping distance), the original BMW E9x M3 brakes will eventually fade and fail with hard use.

This test does not appear to test brake operating temperature over time, nor does it seem to graphically represent performance (brake fade or lack thereof). This test also shows several of the brake kits loaded with Pagid's RS29 pads (an excellent track brake pad), and the other kits loaded with other pads (I am assuming Ferodo FM1000 for the Brembo kit, and stock for the BMW kit).

For an empirical test I would have loaded all of the brake calipers with a high performance pad like the RS29, and logged brake fade in some way.

As-is, even the stopping distance test conducted here is of no use. The data is not accurate due to the inconsistency in pad compound.

The test is done with the compounds supplied by the BBK manufacturer and as approved by the TÜV for the kits. Just like what a consumer would get when buying a BBK from the suppliers.

The test surely could have been done with a non vendor specified brake pad, but if the customer doesn't get that compound, the test would not have been representative anyway... The way they did it, it represents what the customer actually can buy...

AP Racing and K-Sport both use the Pagid RS29 brake pads.

I'm not sure how many consecutive brake tests needs to be done to get sufficient heat over time, but they did 20 subsequent decelerations for each test criteria (100-0 and 200-0 as well as 250-0).


The test was done at the DEKRA test centre with a independent brake and tuning specialist present.

• With the Brembo they write that the pressure point was inconsistent and after installation and bleeding the brake pedal was very low. After rebleeding the pressure point was still inconsistent and often required a double braking action to restore the pressure point.
  
  
• AP Racing has a very consistent pressure point.
  
  
• The K8 suffered from severe vibrations after some use. It's also heavier than stock brakes.
  
  
• PFC is 10kg lighter than the stock brakes! Has a consistent and short pedal travel as well as being easy to modulate.
  
  
• Stoptech has short and consistent pedal travel and the best modulation. Highest deceleration and no fade.
  
  -

[ilikebmxbikes]

My experience with stoptech has always been excellent. Its interesting to compare a regular stoptech kit to a brembo and AP kits. A stoptech trophy kit is a more in line price wise.

I find it really hard to believe the OEM brakes beat the brembo in anything.

[VictorH]

Originally Posted by Ilia@IND

As-is, even the stopping distance test conducted here is of no use. The data is not accurate due to the inconsistency in pad compound.

Seriously? This is the standard by which almost every car magazine measures braking performance and the brake pad issues was addressed by the OP. It would be nice to read this test in English but the German's are usually pretty logical and systematic in evaluating these types of things. What test would you propose that would provide better objective information?

This is probably the most objective comparison we will get regarding BBKs in our cars and appears to be well done. The fact that the results don't support what many people may have believed just goes to show that objective facts don't always fit your belief system. Thanks for posting.

[NELSON.MLGB]

Stoptech does not disappoint for its performance and price. Installed st60, st40 myself a while back, awesome quality, fitment and stopping power.

[FazerBoy]

Well it would certainly be good to get a full translation but it appears that they are doing 40 hard stops in total (from two different initial speeds) so it probably is a fair test of consistency over time.

I've got the Alcon BBK so I'm disappointed that they didn't test that too (or perhaps I'm better off not knowing the result if the original equipment would have performed better ;-)).

[RickyBobby]

Interesting article. It makes me regret removing my stoptechs.
Can anyone translate this?

[LittleBlueBMW]

very interested since my stock brakes failed at the track and keep overheating with track pads and high temp fluid. I am considering stoptechs, that or add a ton of cooling to the rotors.

[FogCityM3]

Awesome find! thx for sharing!

[MasterP]

ST owner here. I'm surprised the PFC ones didn't finish first. But I guess the light weight is what you're buying. Most shocked the Brembo GT finished last!

Regardless of the compounds, having the brake pedal travel be that inconsistent is unsettling. It would have been better if they tested another set just to make sure. As popular as that kit has been it's hard to believe this is the first time hearing about it.

[swhat]

I agree with Ilia. This test is very flawed. Stopping distant is not a comparison for BBKs. If anything it should be heat dissipation. The varying braking compound doesn't make this an even comparison.
With stopping distant, it's is determined by tires, environmental conditions, and brake pad/disc temperatures, and of course the biggest factor of them all, the human driver. If the brake kit can lock up the wheels after 40x hard braking, than it's good.
People normally upgrade their brakes because after repeated hard braking, the OEM brakes become squishy due to inadequate cooling. e.g. Brake fluid boils, brake pads melting.
In the case of this comparo, they used RS29 pads and the ferodos. RS29 is an enduro racing compound vs the Ferodos which I consider to be a street/light trackday compound.

[JAJ]

I agree that if the test involved hammering the pedal and riding the ABS to a stop, then the stopping distances don't mean much - that's a test of the tires and the track surface conditions, and that's all.

The more interesting results are the pedal position, firmness, modulation and fade. But when did they measure those and how? If they were mashing the pedal to the floor and riding the ABS to a stop, then there's no pedal feel to speak of, just the thumping of the ABS. So, unless they tell us the test cycle, it's hard to know what it all means.

And, lastly, the Brembo's were possibly defective, although it could have been something else that was wrong. For instance, most of the brake pads look good but the Brembo pads look cooked. The article doesn't seem to say anything about the rear brakes, and I wonder if the rears were not working properly for the Brembo test - that would explain the weird pedal and the cooked front pads because the fronts were doing all the work.

[evilspiritM3]

Looks like they were using performance friction's 01 pad compound from the photos, and not the stock Z rated street compound.

[0-60Motorsports]

Thanks for posting this up. Love my Stoptech's

[Boss330]

Originally Posted by swhat

I agree with Ilia. This test is very flawed. Stopping distant is not a comparison for BBKs. If anything it should be heat dissipation. The varying braking compound doesn't make this an even comparison.
With stopping distant, it's is determined by tires, environmental conditions, and brake pad/disc temperatures, and of course the biggest factor of them all, the human driver. If the brake kit can lock up the wheels after 40x hard braking, than it's good.
People normally upgrade their brakes because after repeated hard braking, the OEM brakes become squishy due to inadequate cooling. e.g. Brake fluid boils, brake pads melting.
In the case of this comparo, they used RS29 pads and the ferodos. RS29 is an enduro racing compound vs the Ferodos which I consider to be a street/light trackday compound.

Originally Posted by JAJ

I agree that if the test involved hammering the pedal and riding the ABS to a stop, then the stopping distances don't mean much - that's a test of the tires and the track surface conditions, and that's all.

The more interesting results are the pedal position, firmness, modulation and fade. But when did they measure those and how? If they were mashing the pedal to the floor and riding the ABS to a stop, then there's no pedal feel to speak of, just the thumping of the ABS. So, unless they tell us the test cycle, it's hard to know what it all means.

And, lastly, the Brembo's were possibly defective, although it could have been something else that was wrong. For instance, most of the brake pads look good but the Brembo pads look cooked. The article doesn't seem to say anything about the rear brakes, and I wonder if the rears were not working properly for the Brembo test - that would explain the weird pedal and the cooked front pads because the fronts were doing all the work.

Just to reiterate some of the test criterias as explained in the OP:

-For each BBK the M3 was fitted with a new set of Michelin Cup2 tires. Every BBK tested should therefore have the exact same tire condition. IMO the point about tires can therefore be disregarded.

-Every test was done on the same place, at the DEKRA test facility. Same surface and same friction between surface and tire in each test.

Tires and surface was exactly the same for all of the tested BBK's. In that respect, tires, surface and test conditions can be disregarded as factors that can explain the difference in test results. These factors where exactly the same for all BBK's tested.

Stopping distance definitely IS a selling/buying point with a BBK, in addition to the other factors mentioned. As you can see from the test results, there is a 5m difference (more than a M3 car length) between the two BBK that use the same Pagid pads. ABS braking is a good test to find these differences. Because that's a condition where the calipers ability to pulsate is tested. How quick/slow is it's application and releasing of the brake pads. The faster it reacts, the closer to treshold braking can it operate.

If a caliper is slow it takes longer to lock the wheel and longer to release the pads and get the wheel rolling again. In that process, a BBK with a slower reacting caliper will require a longer stopping distance than a BBK with a caliper that has quicker reaction times. ABS braking is actually a extreme test of the calipers qualities IMHO.

Pedal feel was a subjective test. They drove the car on a track and noted pedal feel, modulation and pedal travel.

As regards the Brembo, they don't say anything about it possibly being defective, but just like others here, I wouldn't entirely rule out that option (a defective caliper in itself would be a bad thing for Brembo...)

[NELSON.MLGB]

Originally Posted by Boss330

Just to reiterate some of the test criterias as explained in the OP:

-For each BBK the M3 was fitted with a new set of Michelin Cup2 tires. Every BBK tested should therefore have the exact same tire condition. IMO the point about tires can therefore be disregarded.

-Every test was done on the same place, at the DEKRA test facility. Same surface and same friction between surface and tire in each test.

Tires and surface was exactly the same for all of the tested BBK's. In that respect, tires, surface and test conditions can be disregarded as factors that can explain the difference in test results. These factors where exactly the same for all BBK's tested.

Stopping distance definitely IS a selling/buying point with a BBK, in addition to the other factors mentioned. As you can see from the test results, there is a 5m difference (more than a M3 car length) between the two BBK that use the same Pagid pads. ABS braking is a good test to find these differences. Because that's a condition where the calipers ability to pulsate is tested. How quick/slow is it's application and releasing of the brake pads. The faster it reacts, the closer to treshold braking can it operate.

If a caliper is slow it takes longer to lock the wheel and longer to release the pads and get the wheel rolling again. In that process, a BBK with a slower reacting caliper will require a longer stopping distance than a BBK with a caliper that has quicker reaction times. ABS braking is actually a extreme test of the calipers qualities IMHO.

Pedal feel was a subjective test. They drove the car on a track and noted pedal feel, modulation and pedal travel.

As regards the Brembo, they don't say anything about it possibly being defective, but just like others here, I wouldn't entirely rule out that option (a defective caliper in itself would be a bad thing for Brembo...)

I think they probably have brembo brakes, and does not feel good right now.. the test is just giving us a piece of mind, but honestly, I don't see a $3k-4k difference in performance.

[manari06]

Interesting article! Glad I have ST60 Front and ST40 Rear on my E92!!!

[JD3]

Originally Posted by manari06

Interesting article! Glad I have ST60 Front and ST40 Rear on my E92!!!

Same here, very happy. Very grippy with track pads, very livable with street pads. Best of both worlds and confidence inspiring on track.

[manari06]

Originally Posted by JD3

Same here, very happy. Very grippy with track pads, very livable with street pads. Best of both worlds and confidence inspiring on track.

yes in deed. I visit the Nurburgring quite a bit during summer time and the Stoptech has never fail or let me down.