DIY ABS (was: A thought...)

[Chuck Tomlinson]

> From: George M. Dailey <gmd at tecinfo.com>
> 
> Hi Chuck, I've been thinking about a simple abs for my '58 chevy truck.
> Somthing real simple, that could be done with a basic stamp type PIC. These
> are just thoughts so don't send Dr. Kavorkien to my home :() What do you
> think? Are there oem system that are easy to retrofit? Or is it suicide to
> attempt this?

All the ABS work I've done was on vehicles that originally had production ABS, 
so the vehicle was wired and plumbed for the modulator and wheel speed sensors 
(the key ingredients in ABS).  I suspect it would be a lot of work to fit 
wheel speed sensors to a pre-ABS vehicle (like a '58), but it can be done.

My main concern with DIY ABS: many of the failure modes cause immediate and 
total loss of brake pressure.  Production ABS has more diagnostic and fail-
safe code than control code, so any conceivable failure will be detected and 
dealt with in the safest possible way.

Even with tightly controlled test facilities, experimental ABS is treated with 
utmost care and respect.  IMHO, brake failure is far more dangerous than 
engine failure (although a grenaded engine can spit you into the woods, too).

The bottom line: I highly recommend against DIY ABS.  Without access to proper 
test facilities and, more importantly, many highly experienced ABS engineers, 
DIY ABS is a disaster waiting to happen (and it probably wouldn't wait long).
--
Chuck Tomlinson