I'm not a big ABS fan either, I can see where a full modern ABS system would
be a great driving aid, but the training of how to use it is so lacking...
Personally I prefer to control brake lock with my foot, and not give it to
electrons. Heheheh, can you imagine a Lucas ABS system? I'd never drive
that puppy!!!
Anyhow, here is what the State of Maine discovered after ABS systems started
to be prevalent. The number of single vehicle "off the highway and into the
trees" accidents started to rise dramatically. When they looked at the
numbers, the majority of vehicles involved in these type of accidents were
ABS equipped. Further study showed that most of the accidents involved
evasive action, ie: coming up on an animal in the road at night. After some
vehicle testing, it was found that nailing the brakes and swerving (to avoid
an object in the road) at the same time caused the ABS systems to fully
release the brakes. Apparently the physics of potential lock-up and slip
angles caused the system to not apply the brakes at all during the swerve
action. When the system recovered, the vehicle was headed off the pavement
and into low traction surfaces (grass or loose dirt). Here, the system
would modulated correctly, but due to the lowered surface friction the car
would usually hit something before it stopped on the brakes. In this
specific case, I would certainly prefer the non ABS system, to allow burning
off speed on a high traction surface.
Chris of Maine "one last post..."
'71 wagon "junkbox" driver DR#5 (LZ22 :>)
'72 4dr - project DR#6 (V8)
'69 1600 Bluebird SSS 4dr 1/24 scale
'70 Bluebird Coupe 30th Anniversary Edition 1/60 scale (thanks Lou!)
> -----Original Message-----
> From: Brian Hollands [mailto:bholland@hayes.ds.adp.com]
> Sent: Wednesday, June 06, 2001 6:51 PM
> To: Patrick P. Castronovo
> Cc: Datsun Roadster Mailing list
> Subject: RE: ABS
>
>
> Some of the early ABS systems are easily fooled but newer
> systems are more
> sophisticated. The good ones will sense the speed at each
> wheel and will
> relieve pressure on that brake until the wheel begins to spin
> again then add
> pressure until it starts to lock and again release. They do this from
> several to many times each second. So they keep the wheel
> near its point of
> lock up regardless of pedal pressure so that the stopping
> distance will be
> as short as the available traction will allow. One of the
> problems that has
> also occurred is related to driver training with the system. A police
> officer was killed (If I remember correctly in a Caprice) due
> to improper
> training on ABS system use. The pedal will sort of vibrate as the ABS
> system cycles between adding and relieving pressure from each
> brake. This
> PD had trained it's drivers with the old "pump the brakes" bit which,
> especially with an ABS system only increases the stopping
> distances. When
> the driver felt the pedal vibrating under his foot he interpreted the
> problem as wheel lock and released (began to pump) the pedal
> ultimately
> causing him to enter a corner too fast and lose control.
> The pedal does feel weird when the ABS engages and that can be
> disconcerting.
> Brian
>
>
> -----Original Message-----
>
>
> I have heard some horror stories about the ABS Brakes. They
> do not stop a
> car on ice or sand or Gravel. Any loose soil that allows it
> to slip and the
> brakes release. Pat
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