Why is the Boschmotorsports ABS the cat's meow? Why is this system better than plain old ABS? Why is a car faster with it? Brakes don't stop a car tires do. If a dotR race tire is good for 1g rubber on road how does a fancy ABS help if my generic Porsche ABS also prevents locking at 100% of the tire's capability? The porsche ABS senses lock up. Grippy tires lock later than poor tires.

 

The motorsport version has a more sophisticated brain and valving system. Simply put it can lock and release a tyre significantly faster than the road version. I forget the figures but you can work it out from the specs. Meaning more of the tyres available grip is being used and more often.

 

 

A few differences:
Motorsport calibrations. The street system has internal "limits" on what it expects the maximum braking forces to be. Track tires, pads and suspension can exceed those street pre-determined limits. This is a cause of the "ice pedal" in street abs applications.

Motorsport has much better resolution. Like stated above it can allow the tire to come much closer to threshold braking with much faster cycle rates.

It is programmable for the particular cars specifications like tire diameter, wheel base, track, ect... Street systems are designed around a particular stock tire size so can be out of range when a different size track tire is fitted.

Internal components like pressure valves and pump are designed for frequent abs operation.

Better diagnostic capabilities.


Race ABS doesn't technically make the car faster. It is still limited by a tire and brake component capabilities but it makes it much easier to reach those limits. Most cars do not have a perfectly setup braking system and the ABS will "cover" a lot of that up and allow better braking performance in that case. We installed motorsport ABS on our world challenge 991 cup and did back to back testing at VIR. Fastest laps were the same, it was just easier with the ABS but that car has a very well designed dual-master brake system from the factory. Put it on an early street converted to race Cayman with a generic brake upgrade and you will see a difference.

The first time a motorsport ABS system saves you from having a crash, it probably came close to paying for itself.

 

It has been a while since I've seen the reference material on the Bosch ABS unit, but I believe that is not true. The M4 unit is derived from the same hardware as production car units. The software too is all based on the production software and is actually simpler (again from memory). There are 2 big upsides to the Bosch unit which are A) it has multiple switch positions which vary the parameters to which the unit work to allowing the driver select separate sets of slip targets and acceleration values B) it can be tuned specifically for the vehicle/tire/chassis/etc for the 2 extra switch positions.

Think of it similar to a traction control system. Coding a racecar traction system is not too difficult. The usage case for a race track is actually pretty limited. A street car has to deal with a significantly greater set of conditions than a racecar and as such the software gets more complex with every development of the system. Deal with ice, gravel, wet pavement, dry pavement, a car with just a driver, a car loaded up with 4 passengers and their luggage, ie. lots of lots of variation.

 

Nailed it.

 

Teves also makes a very good race ABS

 

My Teves went into Ice mode. I now have a new car. New car has Bosch unit. Way nicer and actually tells you on the dash what's happening. Very helpful.

Stu

 

 

Interesting. Sorry that happened. I wonder if there was a malfunction with the Teves? I've not hear of that happening before

 

When researching Motorsport ABS I saw a few stories like this (mostly on BMW forums though)

 

What are the benefits over the m4?

 

Area under the curve.

 

Every street ABS has ice mode. We all dread it. Caymans had an issue with it. I think the response from porsche was that's the way it is. There is no flaw. Don't use the brakes as a light switch. Maybe a motorsports ABS just doesn't have that function. Sometimes it is easier to build a racecar because of the narrow range it must operate in. A streetcar needs to operate from 0-150 and from death valley heat to frozen Alaska driven by skilled club racers to one eyed grandma. Streetcar engineering is tough.

 

It's my understanding is that one big difference is that street ABS is a safety device and that Constant duty cycle will overheat it while motorsports ABS can handle more aggressive use.

My 996 GTB came with a MotorSports ABS. My installation gave no feedback. I called the manufacturer thinking there was a problem. They said that was by design. 'Use it. You may sense it work, but not in the pedal. It is meant to meant to be used - and aggressively'

That is what they told me anyway. It seemed to be true. I did sense in my butt when it was working but the pedal wasn't vibrating like a street ABS. Let me be very aggressive on threshold.

Had a switch to turn it off too.

Loved it.

But that's just me and maybe it was also offsetting lack of talent.

F1 has no ABS and they seem to do ok...