re: ABS yes or no? Modifying your ABS sensitivity.

[jkerouac@xxxxxxxxxxxxx]

re: ABS Yes or no?  Modifying your ABS sensitivity.

     Here's maybe.

     Just like the guys who jiggle crankshaft position sensor pickups, 
it should work.  (_Don't ask me about that one, I ain't telliing.)

Here's how to either speed up or decrease the sensitivity of ABS:
      This is an ABS mod that maybe someone has already tried out and 
didn't dare reveal to any sanctioning bodies, or anyone else.

ABS sensors pick up pulses at I believe 40 pulses per wheel rotation 
from s strobe ring that presses onto the hub.  Remember back when you 
would switch your dwell/tach to four, six, or eight cylinders so it 
knows how to translate your spark pulses into engine rpm?  Same idea here.

     How can you jiggle this pulse?  Possibly an electronics whiz can 
make up a black box to intercept the pulses and slow them down or speed 
them up to fool the ABS brain into thinking there is more or less wheel 
slip.  These kind of timing ciruits are nothing special.  Receive one 
frequency as input,  generate another  as output.  I've seen these type 
of timing circuits that can be applied to engine emectronics to 
intercept crankshaft position sensor pulses and delay them by a 
specified number of degrees.  So you can advance the timing of a stock 
Motronic by, for example, four degrees.  More advanced circuits let you 
dial in a whole new advance curve for given rev range increments.  
 Fakes the bal&s out of any  engine management system, just be sure your 
knock sensors are working right.
     Here it would be simpler.  A circuit to plug into the ABS harness. 
 It would have four channels for a four circut ABS.  The circuit would 
receive pulses from the abs sensors.  Then generate a new series of 
pulses at a frequency that is a factor of the timing of the original 
pulses sent from the wheel sensors.
     This could have separate pulse factors for front and rear.  Zero 
factor would effectively eliminate and ABS effect.  Conversely the 
factor would have to be limited so that the ABS isn't tricked into 
always braking either.

Clearly this is underground stuff.  but wasn't upping the rev limit on a 
325e once considered just as clandestine?

     This can also be achieved mechanically to a fixed pulse factor of 
half or two..

     That would require either machining twice as many grooves as are 
already inthe ABS ring on the hub to make the ABS twice as sensitive, or 
welding over and resurfacing every other existing groove in the ring to 
make the ABS half as sensitive.

     If anyone has the means to work on developing this, my car is your 
willing testbed.

Good Luck,

'jk

ps for those with older Motronics, here's a simple way to richen up the 
system. I recall you can put a resistor in the line with the O2 sensor 
signal.  That fakes the computer to thinking you're running leaner than 
you are.  So the ECU richens you up slightly.
     If anyone recalls the value of this resistor, please post it.

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