ABS

[George M. Dailey]

Alright gentlemen, enough general talk about ABS.  Who, out there, has
DIY_ABS? I'm thinking that if you buy the critical parts (modulator), the
ECU should not be hard to build. Wheel speed sensors should also be a snap
to build. Imagine this set up:

4 fast acting solenoid valves, normally closed between each wheel and master
cylinder, each solenoid dumps back to the master cylinder

speed sensor at each wheel

small electric gear pump (high pressure, very low volume), suction side
connected to master cylinder resorvor, discharge connected to each wheel caliper

Here's a controll senerio.

You're testing your DIY_EFI for high speed, 140, 150, 160mph. All of a
sudden a "Big Foot" leaps out on the road. You slam the brakes.

The ECU detects a lower frequency signal comming from one wheel as it locks.
It opens the solenoid valve for a few milliseconds. the wheel speed catches
up with the rest of the crew. This repeats between several wheels untill the
master cylinder stroke bottoms out.  At this point, the electric pump kicks
in and supplies the fluid pressure to the brake callipers. What do you
think? Sure, you would have to add code for stuff like eliminating ABS
control below 5mph and other situations. 

Send your flaming comments to:   throw_it_in at trash.can

On a serious note, it doesn't seem to hard to do technicly. Uh-oh, looks
like trouble.

GMD