Miata Mailing List: July 1993, Message #132
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   From: Al Jenab 
Subject: RE>Re: RE>to ABS or not...
   Date: Thu, 15 Jul 1993 08:53:18 -0400


Andy Poling writes:

"On Wed, 14 Jul 1993, Al Jenab wrote:
> a) It damages the brakes under repeated threshold braking situations.
> The constant pulsing of the hydraulics will destroy rotors and other stuff.


You're the first person I've ever heard this from.  Do you have a source
for this?  I'm genuinely curious, not just being argumentative."

The head instructor at Car Guys for the advanced groups, Dan Dazzo told
me this.  He's also instructor for PCA events and a real good autocrosser.
Students at Car Guys schools are recommended to disconnect their ABS
for two reasons: you won't learn a damn thing about braking, and you'll
probably fry your system, especially at the Point.   Several of my past
instructors who race Showroom Stock also disconnect it.

I should mention that this is in the DRY.  Stock ABS systems just can't
handle the extra heat and stress put on a car during dry racing situations of
any duration.  You'r right about the rain. ABS would be an obvious
advantage on a race track, but the heat build-up would be insignificant
since the coefficient of friction of the track would be so low.  However,
people still disconnect them at schools in the wet to learn how to brake.

"It's only shown up recently, but at least McLaren has it available.  Prost
opted not to use it in Britain (he had some strange electronic problem in
pratice that apparently spooked him), but his teammate (who's name I can
never remember, dammit) had it."

I thought Prost ran a Williams-Renault.  His teammate, BTW, is Damon Hill.
Maybe you mean Ayrton Senna?  HIS teammate sure could use it.:^) Anyway, the
point I was trying to make was that ABS is pretty simple compared to most high
tech stuff in Formula 1, and most chassis contructors & drivers have elected
to not use it.

"> b) Limits driver control.  We don't want no steenking computer modulating
> our brake pedals.

This may be true, but I think it's just racing ego.  How many cars have
you seen slide straight into the runoff area because both front tires were
locked up and sliding?  I think, once ABS becomes more commonplace (i.e.
soon), it will be embraced as yet another technological tool/edge that you
must employ in your effort to win..."

You're probably right about that.  But racing ego doesn't last long when you
lose.  In order to become more commonplace, ABS must offer an obvious benefit.
I don't think that they've gotten it to the point that a good F1 driver wants
it, though.  That says something about the state of technology you can get on
your street car, if mega $ Formula 1 teams can't
get an advantage out of it yet.  As soon as it's an obvious competitive
edge, well you know what happens.

"> c) They can brake faster than the ABS system under most conditions.  They
don'
> t modulate the pedal faster (obviously). The ABS system
>  kicks in at impending lock-up, not at lock-up.  What defines "impending"
> is up to some statistical measure of how brain dead the average driver is
> supposed to be.

That's because ABS's goal is to avoid exceeding your traction envelope.
If it waited until you had exceeded it, you (the average you) would most
likely already be in big trouble by the time ABS came into play."

Exactly my point.  If I could get into the electronics and actively control
when the system engages, I'd be singing a different tune.  My traction
envelope is different from the average someone else's and that will
always mean loss of control over inputs to the car at some level.

"Just ask anyone who's raced a 'vette in SS roadracing why they cream
everybody else in the rain.  They'll tell you it's because they can just
stand on the brakes at the end of the straight and turn into turn one.
I'm sure there are a few at the FATTs Al - ask 'em.  :-)"

I have and they disconnect it in the dry.  So do the serious Porsche and
BMW drivers.

This thread got started as "should I spend 800 bucks on ABS or not" and
my point was that $800 on drivers schools is more likely to save your ass
in an enmergency than ABS.  Moreover, you learn how to turn and handle
the car in spins as well as skids, power slides, etc.  I think ABS is a great

safety feature for a very limited set of cicumstances, in fact that's one
of the reasons I just purchased a Jeep Grand Cherokee (for my wife).  But I
personally feel it doesn't belong on a car like the Miata, and folks are
missing a MAJOR component of the art of skilled driving when they don't learn
how to modulate a non-ABS brake pedal at lock-up.

Also, I'm probably just an old (well, 35) fossil who gets cranky when high
tech starts replacing what I consider to be skill.  I've heard that people
made the same complaints about hydraulic brakes replacing cables.  Oh
well.
-Al