ABS defeat?

[Xenonk]

that was the part I wasnt clear if it had an accelerometer.. I know about the 4-channel sensors. Oddly enough I wonder how many axis the accelerometer has.. if it's 2-axis and not 3, then it would be quite interesting to change the suspension to level out the car and force one of the other axis to read a higher g.

[KartRacerBoy]

Temps now up to 32 degrees F or so. Sad. Development roads are melting and they're the only curvey ones in northern Indiana. But still enough snow to be irresponsible, so I tried the ole rally flick (quick turn right, then a flick left, for a left hand turn) to unsettle the rear, clutched it, and used the e-brake to bring the rear around. Effective, but I've got to carry more speed into the turn. Limits the use of the technique around brick monolith mailboxes! But even more fun than keeping the foot in it and simply using the e-brake to bring the tail around. Whee! Thanks Keefe.

[robinlsb]

that was the part I wasnt clear if it had an accelerometer.. I know about the 4-channel sensors. Oddly enough I wonder how many axis the accelerometer has.. if it's 2-axis and not 3, then it would be quite interesting to change the suspension to level out the car and force one of the other axis to read a higher g.

 

As near as I can tell, from looking at the wiring diagrams, the G-sensor feeds the EBD ( pseudo proportioning valve) logic in the ABS control system. Helps the car stop in a straight line, hinders total stopping distance. Sigh:( And it is in one axis, front to back, at least if the testing of the unit is an indication.

[Metal2You]

So Spec B's shouldn't pull their e-breaks while moving even with the clutch in since they have torsen rear diffs?

[Metal2You]

OK, that makes more sense. I got confused somewhere along the line there. It doesn't really take much

[ClimberDHexMods]

someone could find the power wire for the actual ABS pump and put a switch on that. Then it would cycle on and off with the switch and not throw the ABS light or require a cycle of the key..... i think

 

few years bump...

 

Interested in finding a way to 'soften' ABS instead of killing it completely, thereby allowing EBD to still work.

 

As far as I can tell from the vague vacation pix, B301 Pin 13 (motor power) and (Pin 12 motor ground) drives the ABS motor. I was thinking what if a resistor(s) could be installed to lower the motor voltage or something like that? I don't know much about resistors, so I am asking if this would make any sense? For that matter I don't know much about EBD, so I am not sure whether my goal of softening ABS without softening EBD can be accomplished. Anyone know anything about this?

[mwiener2]

EBD is mainly for emergency stops when you are carrying a load. It really won't help you stop any faster on slippery conditions or at the track

[robinlsb]

EBD is mainly for emergency stops when you are carrying a load. It really won't help you stop any faster on slippery conditions or at the track

 

Well, I have never tested the actual porportioning without EBD in the Subie. On the other hand, I have never driven a race car without some sort of a porportioning valve, including one with a driver adjustable valve.

 

I am pretty dang sure that a Subie with the ABS/EBD defeated will brake worse that than one with it engaged.

[LittleBlueGT]

I tried looking under the dash for the fuse/relay to disable ABS, but not EBD, no luck yet.

 

Anybody have any ideas? I need to spend some quality time with vac pics.

[robinlsb]

I tried looking under the dash for the fuse/relay to disable ABS, but not EBD, no luck yet.

 

Anybody have any ideas? I need to spend some quality time with vac pics.

 

That would be nice. But I spent hours on Vacation pics with no love. There just has to be someone smarter than me (it would'nt take much;)} out there. HELP!!!!!

[ClimberDHexMods]

From what little I've heard, EBD is not something you want to have off in aggressive corner entrys. I don't know how true it is of course.

 

LBGT, they are fully integrated with eachother AFAIK. I looked at the schematic, and there is no indication that you can mess with one without the other.

 

I'm wondering if halving the pump voltage or something like that might still allow the pump to control EBD well enough. Just a wild swing in the dark here, but at least I'm looking.

[LittleBlueGT]

From what little I've heard, EBD is not something you want to have off in aggressive corner entrys. I don't know how true it is of course.

 

LBGT, they are fully integrated with eachother AFAIK. I looked at the schematic, and there is no indication that you can mess with one without the other.

 

I'm wondering if halving the pump voltage or something like that might still allow the pump to control EBD well enough. Just a wild swing in the dark here, but at least I'm looking.

 

 

That is what I thought when I originally did my mod a few years ago. But then someone on some forum (maybe here) said there was a way to do it. Maybe he was wrong, IDK.

 

I don't think that the pump working any differently would help. Remember the old Cavalier ABS, it was like 1 pump per second! It was the most ridiculous ABS system ever IMO.

 

I just use mine in the winter on glare ice, when threshold braking can make a big difference.

 

At my last Solo track event it was raining, sometimes it wasn't too bad, but on some corners it would get soo slick that it seemed impossible to keep the ABS out of the equation, and braking distances shot through the roof. I had a racer drive with me, and he said, "too bad you can't turn off your ABS" I told him I could, but with my DTC-70s f&r the car sure seemed twitchy, so I left em the ABS on.

 

The above made my wonder if I could still keep the EBD but no ABS.

[robinlsb]

That is what I thought when I originally did my mod a few years ago. But then someone on some forum (maybe here) said there was a way to do it. Maybe he was wrong, IDK.

 

I don't think that the pump working any differently would help. Remember the old Cavalier ABS, it was like 1 pump per second! It was the most ridiculous ABS system ever IMO.

 

I just use mine in the winter on glare ice, when threshold braking can make a big difference.

 

At my last Solo track event it was raining, sometimes it wasn't too bad, but on some corners it would get soo slick that it seemed impossible to keep the ABS out of the equation, and braking distances shot through the roof. I had a racer drive with me, and he said, "too bad you can't turn off your ABS" I told him I could, but with my DTC-70s f&r the car sure seemed twitchy, so I left em the ABS on.

 

The above made my wonder if I could still keep the EBD but no ABS.

 

When I put a decent set of snows on, I was scared when the ABS engaged! It wasn't like the stop/ slide used to be, it was "judder". I thought the brakes were screwed.

 

That pedal vibrated like a son of a gun:lol: Tires make a big difference.

[dmanaenk]

Pull the fuse on the relay block under dash. Disables ABS, keeps EBD on.

[LittleBlueGT]

Pull the fuse on the relay block under dash. Disables ABS, keeps EBD on.

 

I will look for it today.

[ClimberDHexMods]

I'm almost afraid to ask, how did you find that out?

[ClimberDHexMods]

Pull the fuse on the relay block under dash. Disables ABS, keeps EBD on.

 

FB-44

F/B Fuse No. 33

(IG)

 

FWIW from behind this fuse there's a GY (Green w/ Yellow Stripe for normal people) that runs directly from the fuse box to Pin 18 of the ABS Control Module connector B301. On the bottom row of that connector, to the inside of the 4 thicker wires, it goes pin 16, 17, 18 where 16 is Black, 17 is LgB (Light Green, Black stripe). I don't like to mess with fuses, would rather cut this wire and hook up a relay to it so it will look prettier.

 

I can't do this myself because my car is apart (still). But I would love to try it when I get done and find a "race track" where I don't mind sliding around a little. Hope this helps someone in the mean time.

[dmanaenk]

I'm almost afraid to ask, how did you find that out?

Nothing scary

[dmanaenk]

FB-44

F/B Fuse No. 33

(IG)

 

FWIW from behind this fuse there's a GY (Green w/ Yellow Stripe for normal people) that runs directly from the fuse box to Pin 18 of the ABS Control Module connector B301. On the bottom row of that connector, to the inside of the 4 thicker wires, it goes pin 16, 17, 18 where 16 is Black, 17 is LgB (Light Green, Black stripe). I don't like to mess with fuses, would rather cut this wire and hook up a relay to it so it will look prettier.

 

I can't do this myself because my car is apart (still). But I would love to try it when I get done and find a "race track" where I don't mind sliding around a little. Hope this helps someone in the mean time.

#33 is the fuse in the fuse block under dash. It is NOT the one I'm talking about. Taking out #33 disables everything (and causes a CEL in my car).

I'm talking about a different fuse, it's on the relay box, and you have to look behind the dash plastic right of fuse door. It's kinda hard to take this fuse out without removing the lower dash panel, but it's doable.

It's circled on the wiring diagram. It cuts out brake pedal sensor signal to the abs/vdc etc (but not to brake lights). So cruise control won't work.

[ClimberDHexMods]

Realized that after reading your other thread (which I couldn't find before )

 

Thank you also for trying to keep to the topic in that thread. Was great to follow your test steps.

 

During your FSM reading, did you happen to retain anything about how the 5eat might operate differently with no brake pedal input? Or the engine for that matter? It gets old reading the manual... each time it's a repeat for a slightly different search query

 

I'll try this either way, but would love to save the time if possible.

 

So this is reversible on the fly with a switch!

[dmanaenk]

Sorry, no. But I'd guess 5EAT logic might care about brake pedal input.

 

Sadly, it's not reversible on the fly, if you mean while the engine is running.

[ClimberDHexMods]

Sorry, no. But I'd guess 5EAT logic might care about brake pedal input.

 

5eat does... at least there is an input for it if i remember correctly. I've done zero testing. Will find out later...

 

Sadly, it's not reversible on the fly, if you mean while the engine is running.

 

Are you still looking into this?

[dmanaenk]

Not at the moment. I'll try one thing when I'm doing smth else that involves messing with wires around the steering column. But even in the unlikely event it would work, the thing I'm gonna try won't help you, since it involves steering angle sensor.

 

Basically I was looking through ABS/VDC diagnostic pages and looking for an ABS/VDC error code to replicate, that would have a note smth like this: "The ABS and VDC operate normally if voltage returns", and the only one I'd try - steering angle sensor.

[ClimberDHexMods]

Eh I'm pretty sure the 5eat uses stearing angle too.

[dmanaenk]

Steering angle - part of VDC. So yeah, some 5eat will have it, but not '05