This past weekend we rolled out a brand new car---our #31 car slated for the new SCCA Pro Racing World Challenger "TC" class. ( www.world-challenge.com
). This was the cars first time on track with the only other effort being dyno pulls to insure the motor and drivetrain worked properly. We used an ABS module from a donor car -- a car that we buy with high miles and no rust before we gut it and put a cage in it, cut metal/weight out, etc., etc....
Watch vid and the end in particular.
What some people might see as **** driving is actually an ABS failure. I have experienced this 4 times now and I'm telling you that it is scary as F__K. Especially when we are hoofin' these cars on the edge. The symptoms are a brief sense of security in the brake pedal followed by a wheel (typically one wheel) locking up along with the other 3 wheels loosing a ton of their braking capability. Essentially you have quadrupled your braking zone distance (which you can see in the video above). The way to get out of this is to feather back off the brakes (which has you covering lots of ground at high speed) and look waaaaaaaay in the distance for a clear space to drive to. This is scary fellas. Scary, scary, scary. Typically you just sneak up on this failure until you go deep in the braking zone and all heck breaks loose. Worse case scenario is your hauling the mail, drive deep and the pedal goes to the floor without any advanced notice.
Here is a view from my car. Listen closely and you'll hear the front left lock up (which means you have about about zero steering capability (which means you let off the brakes to allow for steering which means you are not slowing down which means you are still hauling ***** which means you pretty much dont' stop).
What you don't see/hear/experinece is what is going on with my braking foot. Initial brake pedal application gives me an "oh crap" feel which means I let back off and modulate the brake just enough to slow the car down but prevent lockup. Perhaps you might describe this as braking only 30 or 40% of what you would normally brake. This is why you see the car overshoot what would be a location on the track that you'd normally stop----well behind the first car I approach. WELL behind. Did I mention how kick *** these cars brake? Especially when you remove 700 lbs of weight out of them, add $7K of suspension and race tires. These things stop: S T O P.
So------if this ever happens to you may I suggest you check all 4 of your ABS lines/wires to the Wheel speed sensors first.
Here is another example of when the brakes started to go. We put the car on the trailer shortly thereafter because quite frankly I do not enjoy driving at 7/10th's. Boring and you can't expose the cars handling characteristics (which is what our goal was for that track day).
Brake Failure Vid: http://www.youtube.com/user/meyermotorsports