Spyerx

Ok, so, the 964 cup cars had a badass switch to disable ABS. It's a simple switch on/off.

Question is: how is this wired in? Anyone know exactly how it was done on the cup cars?

Thanks

Gus

If I remember correctly, years back there was a discussion on an ABS cut off on the 964 Forum. The poster did not install a switch but rather a wire loop with a small red flag on it. When the loop was pulled it would turn off the ABS. His point being that the ABS did not work when going backwards and disabling the ABS would allow braking to function should one end up going backwards at a good rate of speed.
I can’t recall who posted, but I am sure it is still on sight and could be found with a good search. Hope this is useful.

Peteinjp

https://rennlist.com/forums/964-foru...ml#post2325695

Spyerx

sweet thank you.

Peteinjp

No problem- let us know how it works out!

Pete

Spyerx

I have a factory switch coming ... they are NLA... mainly as I'm bored and could use a small project :-)

-nick

The Bosch switch is nla now? Porsche part number on those should be 964.615.135.70. But it’s just a generic Bosch 0-340-006-012 switch.

The clever RS?/RSR? solution was an in-line pressure activated switch to turn off the abs. If you’re spinning and abs is confused and preventing brake pressure to the calipers, then adding pedal pressure triggers the switch and the abs gets out of the way. After finding a ground wire fault, spins are the only time I get abs problems.

I picked up a Bosch hydraulic sensor that I’ve been planning use to log brake pressure, and to trigger a pressure based abs defeat. Someday I’ll get to that project

38D

the later ‘92 cups, based on the RS, have this “push thru” pressure switch. I might have activated mine 1-2 times total in my 10 years racing my cup. It’s one of those things you rarely use.

Peteinjp

I can't imagine being able to take my hands off the wheel and push any buttons in a spin..... guess it would require spin practice! Where is the "push thru" pressure smith located?

Pete

Spyerx

I just want it ... because? it's another thing to put a label on and have people scratch head.

On track i WANT abs, I don't run slick, just R-Comp... i can drive w/o abs, and did for a while until i fixed the pump.

BUT, while on the race track a while back some kuncklehead dove into a corner in front of me and lost it, i got into brakes very hard... lockup... flat spot.

Bill Verburg

Just in case here's the wiring and parts used on 964Cups, curtesy of Bob Gagnon

Peteinjp

Where ya gonna put it? Ive seems pics of cup cars but can recall the original location....

P

ThomasC2

I have that switch. It sits where the intensive washer button is supposed to sit, right side of the tac. There’s a hole in the dash that you use. A cool button but never used it on track :-)

Spyerx

So basically the switch is interrupting signal on the abs relay?
so run 2 wires from switch to central electric, cut wire, splice.

that harness looks more complicated but maybe it’s replacing wires i already have.

Peteinjp

Looks like it has an additional circuit for the lighted switch and possibly one additional warning light sliced in?