ABS Stuff

[apowell@ezlink.com]

Todd asked:

> Hey guys, why in the hell would you want to lock up the brakes 
> at any speed?

A fair question.  i have been reflecting on this for a while.  The fact 
is that using ABS allows you to stop a car with steering ability and 
directional control, BUT....not NECESSARILY as quickly as if you 
locked the wheels.

Granted, once a tire stops turning and slides, the friction generated 
IS less than that of a tire turning, but right at the verge of locking 
up.  (Bondurant and others will gladly teach you this "threshold 
braking" technique for non-ABS brakes...for $$.)

However, IMO most ABS systems aren't smart enough to really 
walk that line.  I believe that many of them allow more stopping 
distance to maintain steering control....they just don't "threshold 
brake" maximally (although they do it better than most drivers do). I 
also think that there are times when locking up the brakes will burn 
off speed faster than ABS will allow.

Having said that, I leave the ABS on my 200 turned on.  I figure that 
in 90+% of all driving situations, I'm better off with it on.  If I were 
driving in an autocross, though, it would be off.  

It's kind of like the old saying about which car you should drive to 
be safe..."tell me what kind of an accident I'm going to be in, and I'll 
tell you what I want to drive."  Same for having ABS on.




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Al Powell
Apowell@EZlink.com
1958 Fiat 1200 Spyder "Transformabile"
1983 Datsun 280ZXT
1990 Audi 200
http://www.ezlink.com/~powells/
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