wht01ws6ta

iTrader: (45)

I posted this in the gears and axles section but didn't get any response so I'll try here. Basically, I bought a used 3 channel 9 inch and put it directly into my 4 channel car.

I got the 9 inch installed finally and didn't worry about keeping the ABS and TCS so both lights are on currently.

I thought ABS is disabled BUT when I get on the brakes fairly hard the pedal pulsates as if ABS is still working even though it is not. Is this normal?

Also, I read that with ABS disabled (or disabled by pulling the relay at least) that the brake bias goes back to 50/50 between the front and the rear instead of 70/30 or whatever it should be. Is this the case with my situation?

Help me out if you can!

Adam1982

iTrader: (6)

I believe you are correct with it going back to 50/50. SJM engineering makes an actual abs delete kit that comes with a proportioning valve so you can bring it back to a 70/30 bias (or whatever you like i guess).

wht01ws6ta

iTrader: (45)

Is it at 50/50 automatically?
The braking still feels about the same though except for the pedal pulsating like crazy even when ABS normally wouldn't be kicking in (if it was still enabled).

I know lots of people have done this type of swap before, what did you do with your brakes?

socmguy

iTrader: (18)

My SJM ABS delete just came in the mail. I will be installing it when I put the 9" in. Did you solve your TA problem?

Jditlfm

iTrader: (26)

Pull the fuse out for the ABS the pulsating will stop. Its doing that because the computer thinks its the back tires are locked up when you apply the brakes because the front wheel speed sensors read what ever mph your going and the back ones read 0. Watch how easy that is. Post back when you pull the fuse.

Adam1982

iTrader: (6)

Im having abs / tcs issues not related to the rear end, its a 4channel. Pulling the fuse may stop the pulsing, but i think you will still have a 50/50 instead of 70/30 bias. Im by no means an expert, i cant even figure out whats wrong with mine. This is just the little bit of info i could find doing some research. If being at 50/50 doesnt bother you, pull the fuse and tape over the light i guess. If you want it back to 70/30 I think you will need a kit like SJM has or something similar.

wht01ws6ta

iTrader: (45)

We forced the bolt into the torque arm where it bolts to the diff and then later I centered the rear using the adjustable panhard bar so that the TA is farther away from the tunnel. I don't think it is hitting the tunnel anymore but the rear does clunk, I think it may be the rear itself that is causing the clunk. It's an Eaton trutrak and not a locker so I don't think it should be clunking.

Which SJM kit did you buy?


I will pull the fuse and let you know if the pedal pulsing stops!


I would like it back at the proper brake bias.

2002_Z28_Six_Speed

iTrader: (19)

Brake Bias shouldn't be affected. That is set by orifice size. If it was that would sound like a good way for GM to get sued.

wht01ws6ta

iTrader: (45)

https://ls1tech.com/forums/showthrea...ght=bias+brake
Post #16 mentions it going back to 50/50 because of the ABS motor being disabled. Not sure if that is true or not. I read the same thing somewhere else on here but can't find it now. Anyone know for sure?

wht01ws6ta

iTrader: (45)

https://ls1tech.com/forums/showthrea...ght=bias+brake

That mentions the brake bias going more to the rear with ABS inop.

2002_Z28_Six_Speed

iTrader: (19)

I am thinking about removing the ABS block from my car. The black piece that implements the controls is disabled. But, I still have the junction part.

I wouldn't go as far as to say you are 100% wrong but I don't see how unplugging the ABS adjusts the BIAS unless the ABS is always pulsing to control it.

I guess that the ABS module could have some kind of pintle that is constantly adjustable. I have never sawed the block in half though.

Only kinda taken it apart....




I am thinking about getting a true ABS delete kit with a Strange bias -- I bet that would solve it.

wht01ws6ta

iTrader: (45)

I don't know what happens to the brake bias but I was trying to find out. If bias is affected with ABS simply disable then what you said about the ABS having to always pulse to control the bias makes sense.

What kind of kit are you thinking about getting, SJM or something else?

Adam1982

iTrader: (6)

If it didnt effect the bias, SJM wouldnt offer a proportioning valve to bring it back to 70/30. SJM is also the only ABS delete kit ive seen. If you have seen others let me know.

2002_Z28_Six_Speed

iTrader: (19)

SJM kit removes the ABS block where the proportioning takes place.

socmguy

iTrader: (18)

I got the: 1998-2002 F-body 3 ch. ABS delete kit w/flaring tool. Kit does NOT include LL kit. SJM-2ABS33

It will work with my SLP line lock.

wht01ws6ta

iTrader: (45)

Well I went to remove the ABS fuse as suggested and I see three fuses: ABS BAT SOL 20amp, ABS BAT-1 50 amp and ABS BAT-2 50 amp.

I pull the ABS BAT SOL and then go to test the brakes to see if the pedal still pulsing. Before pulling the fuse the brakes worked fine but the pedal just pulsed all the time so I expect the same braking effect without the pedal pulsing. BUT when I mashed the brakes this time there is no pulsing but at least one of the back tires locks up and the backend of the car starts to come around to the right really fast and I spin around and go off the road backwards on the opposite side of the road. Not good!! I pull the dirt and grass out of my exhaust pipe and replace the fuse and try again (much more cautiously this time) and the pedal pulses and car stays straight. I think one of the front wheels locked up a for a second before I let off. So, even if the rear wheel speed sensors are unhooked and the ABS INOP light is on, the system is apparantly still functioning in some manner to control the brake bias and the stability of the car.

Jditlfm

iTrader: (26)

WOW, sorry to hear about the spin. You think you should have tried it going a little slower first? I told you the pulsating would stop but man your lucky you didn't crash. I am all for abs and i honestly believe it saves lives and don't know why anyone would want to get rid of it on a street car. My advice get the proportioning valve or fix your abs. I feel bad i told you to pull the fuse but honestly it wasn't that smart to go that fast and try it the first time, especially if you didn't know or think a car with disc breaks at full pedal and no abs would do something like that.

wht01ws6ta

iTrader: (45)

Yeah I wouldn't have tried it going that fast except I already had several tried it several times with the "ABS INOP" and like I said the car stayed straight and stopped fine but the pedal pulsed. I thought (from what I read and was told here) that pulling the fuse would just stop the pedal from pulsing but from my experience it does more than that! Yeah I am thankful I didn't crash into anything except skidding backwards into the embankment by the time I was almost stopped. I wonder if I had let off the brakes when I was going sideways on the pavement if I would have flipped the car.

I believe I will get an ABS delete kit with a proportioning valve or get new axles with the exciter rings/have mine machined to accept the exciter rings in order to re-enable ABS. I'm a little leary of driving the car like it is on a long term basis because if that fuse blows for some reason it could be very bad.

wht01ws6ta

iTrader: (45)

Well I currently have the center section out to have 3.89 gears installed so while I have the axles loose I'm thinking about taking them to get machined to accept the exciter rings off of my 10 bolt. Brandon, do you or anyone else know of a decent machine shop around here that could do this?

2002_Z28_Six_Speed

iTrader: (19)

you need to unplug the whole 40 pin harness from the abs mod


this will disable the abs pump motor