Threshold braking or letting abs do its thing

rbahr · 09-04-2022, 10:53 AM

There is a reason that 'real' race cars have an ABS system that is different from the street cars. The 'normal' street ABS is pretty crappy. It kicks in far to quickly, it is possible to experience the 'natural frequency' of the abs typically on washboard surfaces...

Ray

5.M0NSTER · 09-04-2022, 06:45 PM

Quote:

Originally Posted by rbahr

There is a reason that 'real' race cars have an ABS system that is different from the street cars. The 'normal' street ABS is pretty crappy. It kicks in far to quickly, it is possible to experience the 'natural frequency' of the abs typically on washboard surfaces...

Ray

Actually "real" race cars don't have ABS at all. It is forbidden by the rules. Not because they are crappy, but because racing is about driver skill. And if the race car driver can't brake and turn at the same time, he/she deserves to crash and the rest of us gat to watch.

rbahr · 10-31-2022, 10:56 AM

Quote:

Originally Posted by 5.M0NSTER

Actually "real" race cars don't have ABS at all. It is forbidden by the rules. Not because they are crappy, but because racing is about driver skill. And if the race car driver can't brake and turn at the same time, he/she deserves to crash and the rest of us gat to watch.

Absolutely not true: I KNOW for a fact that Porsche race cars have ABS - and it it's very different from what is found in road going cars - in general they have options for different surfaces - wet or dry, allow for different tire diameters, and allow for different amount of lockup before intervening. A GOOD race car driver can stop faster with threshold braking on a dry surface that with ABS.

Now the Motorsports ABS are not cheap - Porsche charges ~$10K for the Box (made by Bosch)... but they are better behaving on a race track -

The street systems also can be prone to 'ice mode' - which I can assure you is 'interesting' on a race course, having experienced it...

Ray

jefe2000 · 10-31-2022, 02:19 PM

Here's a more mathematical approach to answering the question:

PackPride85 · 11-03-2022, 07:03 PM

Quote:

Originally Posted by jefe2000

Here's a more mathematical approach to answering the question:

I'm glad someone posted this. Anyone that claims they can stop faster than ABS is lying. If you don't agree, prove me wrong.

rbahr · 11-07-2022, 05:54 PM

I watched the video, and it is not clear to me that the ABS systems found on passenger cars does as good a job at keeping the wheel speed in the 'good' zone as the presenter suggests!

A corner case,but: I also know that abs does have problems and a person can often stop faster in snow without ABS than with.

Ray

Ray

09-04-2022, 10:53 AM	#23
rbahr Private 35 Rep 70 Posts Drives: To many & not enough Join Date: May 2022 Location: Carlisle, MA iTrader: (0)	There is a reason that 'real' race cars have an ABS system that is different from the street cars. The 'normal' street ABS is pretty crappy. It kicks in far to quickly, it is possible to experience the 'natural frequency' of the abs typically on washboard surfaces... Ray
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10-31-2022, 02:19 PM	#26
jefe2000 Lieutenant 740 Rep 483 Posts Drives: 2018 M2 6MT Join Date: Feb 2020 Location: San Francisco Bay Area iTrader: (0) Garage List 2018 BMW M2 [10.00]	Here's a more mathematical approach to answering the question:
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11-07-2022, 05:54 PM	#28
rbahr Private 35 Rep 70 Posts Drives: To many & not enough Join Date: May 2022 Location: Carlisle, MA iTrader: (0)	I watched the video, and it is not clear to me that the ABS systems found on passenger cars does as good a job at keeping the wheel speed in the 'good' zone as the presenter suggests! A corner case,but: I also know that abs does have problems and a person can often stop faster in snow without ABS than with. Ray Ray
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