Winter driving and our ABS

[ross1]

Does anyone else feel our ABS is invoked too easily in low grip situations?

I'm running 15" Blizzaks and can tell there is plenty of grip left when braking but the ABS intervenes so I always wind up easing the brake pressure so as not to feel and listen the ABS pulsing.

I've disabled it for ice trials in the past but don't feel it's a good idea on the road as it's great in the dry.

Does anyone know how to change the threshold at which the ABS comes on?

[David325e]

Wild shot in the dark- would that involve changing abs modules?

I remember when I had the 525 and 540 at Radford. Hills up the wazoo plus 2-4ft of snow. The ABS would engage, which made the car slip, which made it even worse. Like I slammed on the brakes on marbles when I could stop almost normal distances by pumping the pedal.

[demetk]

I use snows on my cars and my ABS always engages at wheel lockup and not before. Can caliper drag can causing earlier engagement?

[ross1]

I use snows on my cars and my ABS always engages at wheel lockup and not before. Can caliper drag can causing earlier engagement?
Every car I've owned with ABS is like this and it's damn annoying.
I suspect it engages at the first sign of slipping, this doesn't allow for threshold braking. I'd love to dial it back a bit but haven't the foggiest idea how or if it could be done.

[Binjammin]

Ross, you may want to meter your ABS sensors to see if one is out of spec. Even on dry pavement at slow speed, I've been in cars that would trigger ABS going over a bump, it's entirely possible that you've got a weak or dirty sensor, or tone ring that's rusty, and that's causing premature engagement.

[ross1]

Ross, you may want to meter your ABS sensors to see if one is out of spec. Even on dry pavement at slow speed, I've been in cars that would trigger ABS going over a bump, it's entirely possible that you've got a weak or dirty sensor, or tone ring that's rusty, and that's causing premature engagement.


By the time I get to doing that the roads will be dry. It's been the same every E34 I've owned as well as other cars. I'm certain it's working correctly, just too intrusive for my taste. Same with the ASC on the wife's e39, it can be turned off though.

[Binjammin]

By the time I get to doing that the roads will be dry. It's been the same every E34 I've owned as well as other cars. I'm certain it's working correctly, just too intrusive for my taste. Same with the ASC on the wife's e39, it can be turned off though.

Well, I hear that, but taste is all relative. For example, my abs rarely ever ever ever came on in my 535, and that even included the night I drove 1.1 miles in like 2 hours on a sheet of ice. I don't particularly like ABS either, but I've driven enough cars to know that it shouldn't just come on because of snow, you'd have to have one wheel locked up to trigger it. If it's coming on with just braking, you should probably check it out.

[ross1]

Well, I hear that, but taste is all relative. For example, my abs rarely ever ever ever came on in my 535, and that even included the night I drove 1.1 miles in like 2 hours on a sheet of ice. I don't particularly like ABS either, but I've driven enough cars to know that it shouldn't just come on because of snow, you'd have to have one wheel locked up to trigger it. If it's coming on with just braking, you should probably check it out.

Not "just braking". My complaint is that you can't get to the grip threshold without this damn nanny taking over.
We are getting a pretty good snow here today so I took to some fun unplowed roads. I don't know if I can out brake the ABS on the dry but certainly could in snow. It seems to allow no slip, perhaps comes on before that. A small amount of slip is optimal.

[Layne]

It would be easy to wire a switch into almost any of the ABS system's wires to cause it to fault out and not run when the switch is open, but I would guess the slip threshold is hard programmed and cannot be changed.

[Binjammin]

It would be easy to wire a switch into almost any of the ABS system's wires to cause it to fault out and not run when the switch is open, but I would guess the slip threshold is hard programmed and cannot be changed.

I always wanted to run direct power to the front ABS solenoid to see if I could make a ghetto line lock.

[ross1]

It would be easy to wire a switch into almost any of the ABS system's wires to cause it to fault out and not run when the switch is open, but I would guess the slip threshold is hard programmed and cannot be changed.

My prior method was to yank a relay out of the unit when I wanted it off. The switch is a consideration, at least it would let me do quick changeovers.
If it's possible to change the threshold someone here will know about it.
Waiting for guys like Shogun et al who've been deep inside the electronics of these cars.

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I always wanted to run direct power to the front ABS solenoid to see if I could make a ghetto line lock.
:confused :)

[Binjammin]

My prior method was to yank a relay out of the unit when I wanted it off. The switch is a consideration, at least it would let me do quick changeovers.
If it's possible to change the threshold someone here will know about it.
Waiting for guys like Shogun et al who've been deep inside the electronics of these cars.

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:confused :)

It should work. Worst case scenario would be to build a PWM circuit that keeps it closed rather than full voltage, a diode on the line back to the ecu for safety, and away you go. It's a solenoid that applies pressure to the brakes, there's no reason it shouldn't work.

[Layne]

Doesn't the solenoid release pressure from the calipers, not lock it in? Ie; you've applied the brake too hard so the tire slips, the solenoid releases some pressure so that the tire rotates again...? I never really got into it, but I thought that's how it worked.

[Layne]

ASC+T applies pressure to the rear brakes... Just re-pipe it so it effects the front instead. The more you spin the rear wheels, the more pressure the system would apply trying to stop you :rofl: Disconnect the ASC throttle of course.

[Binjammin]

Doesn't the solenoid release pressure from the calipers, not lock it in? Ie; you've applied the brake too hard so the tire slips, the solenoid releases some pressure so that the tire rotates again...? I never really got into it, but I thought that's how it worked.

It has to be able to do both, as it continually applies and releases the pedal continuously.

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ASC+T applies pressure to the rear brakes... Just re-pipe it so it effects the front instead. The more you spin the rear wheels, the more pressure the system would apply trying to stop you :rofl: Disconnect the ASC throttle of course.

Now that's funny :rofl

[priler]

have you tried a different tire width,air pressure or tire model? anything you can do to increase traction.(adding lots of weight would be another but undesirable).

changing the algorithm somehow would probably do it but I've never messed with that on any car,ever.




edit to add: perhaps even changing brake pads that give you more modulation instead of a quick,sudden bite.

[ross1]

have you tried a different tire width,air pressure or tire model? anything you can do to increase traction.(adding lots of weight would be another but undesirable).

changing the algorithm somehow would probably do it but I've never messed with that on any car,ever.




edit to add: perhaps even changing brake pads that give you more modulation instead of a quick,sudden bite.

That's the thing, I have traction available. The darn nanny just has a low threshold.

[sse34]

I always found the abs to be a new sense

[shaytanabyad]

Just want to help out a bit...

nuisance - a person, thing or circumstance causing inconvenience or annoyance. Just one of my pet peeves (a minor annoyance that an individual identifies as particularly annoying to himself, to a greater degree than others may find it.)

[Layne]

I think his phone must have auto corrected that. Surely no one believes that "nuisance" is "new sense". Surely.

[T444E]

I always found the abs to be a new sense

dot

[Binjammin]

I think his phone must have auto corrected that. Surely no one believes that "nuisance" is "new sense". Surely.

Think about who posted it for just a minute.

[breadvanracing]

Buy an E46, your ABS will be disabled most of the time you drive it. ;-) I always found that I was able to brake relatively hard on those tires before the ABS kicked in. I'm more disappointed with the equivalent tire on my E46, but I don't have the total vehicle weight anymore, or the big V8 over the front wheels to aid traction.

I guess you're getting your money's worth this winter on those Blizzaks though. I know I am with mine.

[ross1]

Buy an E46, your ABS will be disabled most of the time you drive it. ;-) I always found that I was able to brake relatively hard on those tires before the ABS kicked in. I'm more disappointed with the equivalent tire on my E46, but I don't have the total vehicle weight anymore, or the big V8 over the front wheels to aid traction.

I guess you're getting your money's worth this winter on those Blizzaks though. I know I am with mine.
Yes, I am, thanks again Gavin.
I can brake pretty hard and feel I could brake harder if it were not for...........

[shaytanabyad]

Think about who posted it for just a minute.

No need to be a dick.

I was just trying to help him out, not poke fun.

[Binjammin]

No need to be a dick.

I was just trying to help him out, not poke fun.

Considering who posted it, and the context of this thread, I wasn't. I was simply pointing out that given his post history, it's very likely that he didn't know the difference, and won't until he reads this thread.

[djb2]

Buy an E46, your ABS will be disabled most of the time you drive it. ;-) I always found that I was able to brake relatively hard on those tires before the ABS kicked in.

Same thing with an e39... the ABS units in those are destined to fail.
When they do, you'll freshly appreciate the value of ABS.

Our freeway commute sometimes involves 70MPH panic stops. When the ABS unit failed we quickly ended with flat-spotted tires. One tire would lock up while the others still had plenty of traction. Sometimes I wouldn't even realize it until I saw the tire smoke.
I have plenty of experience with hard braking on cars without ABS, and can't recall really flat-spotting a tire before. It was just this combination of suspension, tires and brake pads.

The point is that you might really be losing traction on one wheel without realizing it, and the ABS is doing its best to help you.

(And for those of you that imagine you can avoid a freeway panic stop by careful driving, you haven't been in real traffic. There is always an idiot that slams to a stop when they see a brake light in the distance. If you anticipate that, you become the idiot. Leaving a big gap in front of you invites the wildest driver to change lanes right in front of you when braking starts, while braking hard.)