I didn't mean, keeping the brakes locked. I meant braking right up to the
verge of locking, using "pedal" (as opposed to "manual") control. And I
also contend that tests of early ABS systems evinced this exact
characteristic -- slightly longer stopping distances on dry pavement; in
essence, trading off distance for stability. I concede that I may be
out-of-date, and that modern systems with perhaps faster cycle times or
better algorithms, are superior in this situation.
REwald9535@aol.com had this to say:
>Max,
>Two misconceptions here. First having the brakes on 100% does not give the
>shortest possible stopping distance. Locked brakes take longer to stop that
>brakes that are not quite locked. Secondly, ABS does not "release" the
>brakes in the sense of turning them off and then back on again. What ABS
>does is when a wheel starts to lock to reduce, slightly I might add, the
>pressure going to the caliper thus allowing the wheel to keep turning. By
>keeping the wheel right on the verge of lockup the shortest stooping
>distance
>is achieved, and control is maintained.
>In the web page that Eric supplied was an interesting fact. From 140 Km/h
>on
>wet pavement a test car W/O. ABS took 181 meters to stop, the same car with
>ABS took 112 meters a difference of 69 meters. At the point where the ABS
>car stopped, the non-ABS car was still traveling something like 86 Km/h!
>Now comparing two different cars one with ABS and one without is a dicey
>proposition, a great ABS system on a lousy brake system will not be optimal
>nor will a lousy ABS system on great hydraulic brakes.
>The web page Eric supplied is
><http://www.mercedes-benz.com/e/innovation/rd/forschung_nov96.htm>
>Go to planning and trials.
>Rick Ewald
>
>In a message dated 01/09/2000 4:41:51 PM Pacific Standard Time,
>mvheim@studiolimage.com writes:
>
>> I believe that is the case, due to the fact that cycling the brake on and
>> off means that it is actually applied less than 100% of the time, which
>> would, of course, result in the minimum distance.
>>
>
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.
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