From practice to the real world.

From practice to the real world.

"These build journal entries are part of a special series on the development of the e9X M3 Custom AP Racing Big Brake Kits by HaimusRacing and written in collaboration with Antonio and his engineering team. 

In this journal entry, I provide Haimus' objective performance results and compare to the SportAuto test."
- Matt

Internal Performance Testing. 

The test settings. 

The tests were conducted by HaimusRacing on their E92 M3 Clubsport build. 


The tires picked for the test were the Continental SportContact6 tires in stock 19" sizes. 

Pads used. 

Pads were both street biased compounds – from OEM BMW and ATE with similar coefficients of friction. Antonio and his team used OE level pads to have a better assessment of the objective performance gains the Clubsport kit versus OEM. 


The same street road with similar weather conditions was used to perform the tests. 

Results vs OE & PFC. 

Improvements over OE:

100-0 kph AP Custom Clubsport (Internal testing)  PFC (SportAuto)
Average 0.4m -
Best 0.7m 0.9m


Haimus achieved 0.3 meters of improvement in the 100-0 stopping distance the first time out.

After 7 consecutive stops, the repeatable average improvement was 0.4 meters per stop with a peak difference of 0.7 meters on the fourth stop. The PFC big brake kit improved upon the OEM brakes by 0.9m, topping the HaimusRacing Clubsport kit's best of 0.7m.

There are 2x caveats. 


SportAuto used brand new Michelin Sport Cup 2 tires. HaimusRacing used Continental ContiSportContact6 (UHP) tires. 

These 2 are not the same.  

Per AutoBild's 2020 UHP tire testing, the ContiSportContact6 was precisely 0.6 meter behind the Cup2s when compared in similar conditions, on the same car. 


The PFC kit came fitted with their Z rated pads. It is their Clubsport type pad designed for fast road and track day applications. 

This chart shows what I assume to be some form of friction metric on the Y axis over a wide temperature range over X.

PFC's Z rated pad chart. We're again missing an Y axis metric. 

What this all means is the PFC pads bite more, and are more resistant to fade, improving performance over OEM style pads. 

We can make the deductive assumption that the Haimus Custom AP Clubsport kit would perform better with similar tire and pad compounds. 

Will we ever get a picture perfect BBK test? I don't think so.

Does it matter? I don't think so either.


BBKs are not purely about stopping power, neither was it the pure optimization target by Antonio and his team. Improved braking performance were one of 6x targets. It has been achieved. 

Initial targets.

The main targets were laid out in the 2nd entry to this Special Series to this Clubsport kit. 

  1. Lightweight
  2. Improved braking performance
  3. Street friendly and track suitable
  4. Superior brake bite and brake feel
  5. Improved heat dissipation 
  6. Accessible, affordable consumables

Looks matter, it's undeniable. The caliper design and custom painted finish are critical drivers of purchase decisions. 

Prologue to my driving impressions. 

Use change. 

I was running fitment experiments in parallel with the E60 M5 and I got caught with my pants down. The delays in getting parts from BBS and H&R put me in a bind. 

Still, it was worth the wait :) 

I ended up having to use the E92 M3 as a daily driver from April to September as the E60 M5 was stuck at the shop. 

This got prolonged into October as evidently something else had to fail on the V10: the electrical radiator fan went out. Because V10 M5, I took on the challenge to fit a lightweight flywheel while in there. 


I got the BBK installed by the guys at InnovAuto in late August. I unfortunately wasn't available to document the process.

As a reminder, this is a complete kit. It includes everything you need to do the install. 

It's relatively straight forward and took the guys about 90 minutes to do the front. 

Up next: I drive the car for 4,000 km in every other environment available.

Rain or shine.
Cold or warm. 
It got driven. 
It got beat on. 

I do my best to convey & visualize the improvements. 

I finally get to reveal my ace-in-the-hole and I wrap it up with my final thoughts. 



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