Sometimes ABS sucks

[idosubaru]

or a pedestrian hit

a very good friend of mine hit someone, a pedestrian, massive injuries and they never looked at his vehicle.

[nipper]

Somewhat interesting/related reading:

http://www.oramagazine.com/pastIssues/0411-issue/041102t-finesse.html

 

Don't skip the last two paragraphs.

 

Nice to see something that validates what I have been saying.

 

Now there is a few options to "control" the abs. One is a simple momentary push button switch. The second method, whic i am thinking of favoring is a timed latching relay. You can push a button, latch the relay, which would disable the ABS, for anywhere from .1 seconds to 1 hour, depending upon which timed latching relay you get.

 

For more hard core off road driving you can come up with something else.

 

nipper

[nipper]

a very good friend of mine hit someone, a pedestrian, massive injuries and they never looked at his vehicle.

 

I did hit a pedestrian myself (well he hit me) and they impounded the car and went over it with a fine tooth comb.

 

nipper

[crazyhorse001]

The problem I see with downhill in snow with ABS is that you start at well over the threshold speed & can't really get under it, in an auto. Consider for a moment, how fast does your car go, in gear, at idle? I'm betting better than 3mph. However fast your car goes at idle, WILL be your terminal velocity downhill, on a slippery surface. This is when the human safety device steps in to shift to N, or use the E-brake.

 

In those conditions, I'll take my manual brake, manual steer, Pinto ANY day over any of my modern ABS equipped cars. Any mistakes made are attributed DIRECTLY to the loose nut behind the wheel.

[hankosolder2]

The other problem with ABS which hasn't been touched on is the effect of bad shocks/struts on the functioning of the ABS system, even in dry conditions.

I read an interesting paper about how even one faulty strut can greatly increase stopping distance- the ABS computer interprets even minor wheel "dribbling" as lockup and tries to equalize speed.

 

Personal experience- I have an old BMW with somewhat tired struts- because it's a fairly stiffly sprung car, it doesn't give the "wallowing" feeling which says "worn struts" to most folks. Tire wear is normal. However, if I have to brake moderately hard over a choppy surface (say, railroad tracks) the ABS will activate and lengthen the stopping distance significantly.

Yep, got to do something about that one of these days.

 

Nathan

[nipper]

The other problem with ABS which hasn't been touched on is the effect of bad shocks/struts on the functioning of the ABS system, even in dry conditions.

I read an interesting paper about how even one faulty strut can greatly increase stopping distance- the ABS computer interprets even minor wheel "dribbling" as lockup and tries to equalize speed.

 

Personal experience- I have an old BMW with somewhat tired struts- because it's a fairly stiffly sprung car, it doesn't give the "wallowing" feeling which says "worn struts" to most folks. Tire wear is normal. However, if I have to brake moderately hard over a choppy surface (say, railroad tracks) the ABS will activate and lengthen the stopping distance significantly.

Yep, got to do something about that one of these days.

 

Nathan

 

 

Actually that goes for any car with bad struts or shocks. Part of the job of the dampner is to keep the wheels on the ground. When a damper is bad (ever see a car dribbling a wheel on the highway and wonder how in hell can they not feel that) it is a MAJOR saftey item. When the trie is bouncing you have no control over that wheel.

 

nipper

[subaruplatt]

I had ABS save me during a high speed pile up, I actually drove right around it. I have been saved by non ABS setups by good tires. I mean literally standing on my brakes so hard that my rear wheels almost came off the ground.

 

A good ABS setup won't even engage as long as you still have traction. I would drive it the same as if it weren't there.

 

Used to creep along on sheer ice with my old VR6 and the ABS would operate at any speed I mean 1 mph.

 

Then I realized how sophisticated ABS really was.

 

So now they have ESP. Sort of an ABS ruder.

 

In the real world a combination of outfitting, maintenance, tires, ABS, and driving might save your Bacon.

[subsince77]

My Sub is the first ABS car I've ever had. I have never liked it, but I thought it was just because I grew up in Colorado and North Dakota driving many months of the year on winter roads with regular old brakes. I learned early how to use my gears and pump the brakes to stop. I almost never give the ABS a chance to work, because my foot isn't on the brake that long. Anyway, never liked it, thought I was just getting old, turns out I was at least partially right.

[nipper]

You do know that by pumping ABS you can actually make your stopping distance longer?

 

nipper

[Virrdog]

And sometimes ABS absolutely rocks.

 

Isn't that how it goes with everything in life? What's the point of this thread again?

[CNY_Dave]

After some more experimentation last night, it seems that:

 

1) In 1st, threshold speed is about 10mph

 

2) Not sure, but in D I think its even lower

 

3) You can use the ABS to get down below threshold speed, then release the brakes, then lock 'em up IF you have it in 1st (to get the higher threshold speed), BUT, you must leave your foot off the brakes for about 1/2 second to allow the ABS to be come 'disinterested'.

 

4) As a last resort, just turning the key to 'off' works just fine, but will be a detriment if you need power again quick.

 

I didn't check threshold speed in 2nd, the folks on the street were looking at me funny enough as it was.

 

If I were going off-road a lot, there is no doubt in my mind I'd put in an ABS kill-switch, for going off-road.

 

In the interests of science, I'd love to put an LED on the ABS solenoid (or whatnot) for each wheel. I'm not sure there's any exposed wiring, though.

 

Dave

[nipper]

In the interests of science, I'd love to put an LED on the ABS solenoid (or whatnot) for each wheel. I'm not sure there's any exposed wiring, though.

 

Dave

 

 

In laymans terms...

 

"here, hold my beer"

 

:-p

 

Couldnt resist

 

nipper

[idosubaru]

is it possible that old sensors are somehow more susceptible to this? would new sensors help at all, or is that completely unrelated? from the few that i've removed they degrade quite a lot.

 

any other ideas on dealing with this?

 

+1 on bad struts...just drive an XT6 with flat air suspension and yo'ull see just how dangerous bad struts are, and those are non-ABS vehicles. i know that's a stretch, but definitely shows the importance of good suspension on any vehicle.

What's the point of this thread again?

it's getting very important safety information out there. what other subaru related item from the factory creates a situation where it is physically impossible to stop??!! that's a big deal! i didn't even know that this was an ABS issue, i just assumed something was wrong with "my" car. discussion leads the way to improvements or tips on how to deal with it.

[nipper]

is it possible that old sensors are somehow more susceptible to this? would new sensors help at all, or is that completely unrelated? from the few that i've removed they degrade quite a lot.

 

any other ideas on dealing with this?

 

+1 on bad struts...just drive an XT6 with flat air suspension and yo'ull see just how dangerous bad struts are, and those are non-ABS vehicles. i know that's a stretch, but definitely shows the importance of good suspension on any vehicle.

it's getting very important safety information out there. what other subaru related item from the factory creates a situation where it is physically impossible to stop??!! that's a big deal! i didn't even know that this was an ABS issue, i just assumed something was wrong with "my" car. discussion leads the way to improvements or tips on how to deal with it.

 

Its not a sensor issue.

 

This is an ABS issue, in all cars. You dont hit this too often, but you do, you need to know how to deal with it. The same way everyone should know how to deal with a loss of brake boost, a loss of power steering, how to handle a blow out, and what to do when the idiot lights come on or the gauges peg.

 

You can not rely 100% on technology. If you could, a car wouldnt need an operator.

 

Traction control alos has its failings, as we will see so does stability control. Both will give people a false sense of confort, and drive at the threshold of physics, where there is no chance of recovery.

 

nipper

[hankosolder2]

Actually that goes for any car with bad struts or shocks. Part of the job of the dampner is to keep the wheels on the ground. When a damper is bad (ever see a car dribbling a wheel on the highway and wonder how in hell can they not feel that) it is a MAJOR saftey item. When the trie is bouncing you have no control over that wheel.

 

nipper

 

Nipper,

 

My point was not that worn struts are a great thing for the braking and handling of a car, but rather, that ABS takes a less-than-ideal situation (a car with worn struts) and greatly worsens it. The test I was speaking of was measuring the stopping distance of a car with one worn strut with and without ABS enabled in dry conditions. Without ABS, the car stopped significantly sooner. Let's face it- especially in states without vehicle inspections, a signficant number of cars on the road are going to have worn struts...it's worrying when a 'safety' aid like ABS is a detriment to safety under several not that unusual conditions...loose snow and worn suspension.

 

Nathan

[subiemech85]

when ABS SUCKS

 

frozen "skating rink" accelerate to max speed then slam on brakes and see how far you can slide

 

now that's fun !!!

[nipper]

when ABS SUCKS

 

frozen "skating rink" accelerate to max speed then slam on brakes and see how far you can slide

 

now that's fun !!!

 

Thats when everything sucks short of studed tires

 

nipper

[subiemech85]

if you have studs, you are disqualified because you would tear up the ice and stop too soon, where's the fun in that?

[nipper]

if you have studs, you are disqualified because you would tear up the ice and stop too soon, where's the fun in that?

 

Arent most skating rinks surrounded by walls?

 

 

nipper

[Manarius]

ABS didn't help me yesterday in the slush. However, neither did my tires. It was a lose-lose situation (luckily I didn't lose anything more than my pride).

[fnlyfnd]

I use the walls to pull myself up

[subsince77]

You do know that by pumping ABS you can actually make your stopping distance longer?

 

nipper

 

Yup. But old, old habits are hard to break (brake). I'm working on it.

[idosubaru]

the recent storm proved the same thing...they suck in the snow. going down hill is just madness. the snow tires help some, but still annoying. i'll probably go play another day and see the difference between pulling the fuse and not pulling it...just for kicks. i didn't check, does ABS have a dedicated fuse in the interior box?

[BruceyWV]

Going down steep hill (35 degrees or so), Heavy slush, First gear as at the bottom of the hill is an intersection/stop sign.

 

Never topped 5 mph, and I still managed to just slide right by the stop sign and the state trooper, no ticket though, he knew I was trying.

 

Would simply kicking it into neutral have worked better and disable ABS? I'd feel more confident know I can simply kick the shifter forward and have full lock up when needed than disabled the ABS permanently by pulling the fuse.

 

(I did that last winter, still better than having it, but its the other side of the coin.)

[nipper]

Going down steep hill (35 degrees or so), Heavy slush, First gear as at the bottom of the hill is an intersection/stop sign.

 

Never topped 5 mph, and I still managed to just slide right by the stop sign and the state trooper, no ticket though, he knew I was trying.

 

Would simply kicking it into neutral have worked better and disable ABS? I'd feel more confident know I can simply kick the shifter forward and have full lock up when needed than disabled the ABS permanently by pulling the fuse.

 

(I did that last winter, still better than having it, but its the other side of the coin.)

 

I thought we addressed this a few times.

 

Yes put the car in neutral. Read the entire post, i think someplace in here (or the other snow thread) is an article and myself explaining why.

 

Also another PS if you lock all 4 wheels, the ABS is going to think you are stopped, so it isnt going to do a thing. Even if the car itself is still moving.

 

nipper