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Car Forum / Driving, Maintenance, Tuning / Driving / December 2007ABS, snow, steep downhill- car won't stop.
OK, is this a subaru implementation issue, or an ABS-in-general issue? Going down a steep snowy hill, quite slow, car cannot stop due to the ABS- just cycles and cycles, keeping car moving slow. The subie knowledgeable say in this situation, it will stop if you put it in neutral (its an automatic). This was the kind of snow where if you lock up the tires you dig through the crud and stop in short order- used to have to do that with my pickup, and on this car, the e-brake stopped it right quick. Overall I am finding the ABS to be a positive, always wondered if there was a case where it would be a negative. Ayuh, there sure is! Dave > OK, is this a subaru implementation issue, or an ABS-in-general issue? > > Going down a steep snowy hill, quite slow, car cannot stop due to the > ABS- just cycles and cycles, keeping car moving slow. Don't need a hill for that, at least in consumer level ABS of ten years ago. I've heard things have improved but haven't driven a recent car in snow situation where the ABS kicked in. > The subie > knowledgeable say in this situation, it will stop if you put it in > neutral (its an automatic). No reason for it to stop by doing so unless the ABS de-activates with a neutral gear selection. > This was the kind of snow where if you lock up the tires you dig > through the crud and stop in short order- used to have to do that with > my pickup, and on this car, the e-brake stopped it right quick. I worry about the a.s end kicking out with the e-brake. But yeah the abs endless cycle at 5mph or less is really annoying. Brake lock at low speed is not a problem and the ABS should not function at low speed. > In article <fb434613-8353-4312-9fc0-f63502b59...@e6g2000prf.googlegroups.com>, spamTHIS...@yahoo.com wrote: > [quoted text clipped - 21 lines] > endless cycle at 5mph or less is really annoying. Brake lock at low speed > is not a problem and the ABS should not function at low speed. Placing it in neutral removes the driving force of the engine, which even at idle adds just a little downhill push. I've heard folks say they've heard it works, but haven't found anyone who says they did it and it helped. I'm leery of putting a disble switch in the ABS system, but I drive in low-traction situations often enough I'll find some method to compensate for this set of conditions. Dave > Placing it in neutral removes the driving force of the engine, which > even at idle adds just a little downhill push. I drive MT cars and that has nothing to do with the ABS cycling. > I've heard folks say they've heard it works, but haven't found anyone > who says they did it and it helped. No reason it should help other than if there is some programming in some cars that causes the ABS to turn off when placed in neutral. > I'm leery of putting a disble switch in the ABS system, but I drive in > low-traction situations often enough I'll find some method to > compensate for this set of conditions. ABS blankout is IMO an unacceptable condition. The ABS has speed sensors so all it would need is a few lines of code to tell it not to pump if speed is less than X. > In article <3cb67299-02b4-4fd3-906b-77700fa25...@i12g2000prf.googlegroups.com>, spamTHIS...@yahoo.com wrote: > [quoted text clipped - 16 lines] > so all it would need is a few lines of code to tell it not to pump if > speed is less than X. I don't really want to put in a cutout, but I'll be damned if I'm going to drive something that won't stop. A good workaround is out there, I just gotta find it. Unfortunately, changing the ABS controller code is outside my capabilities. Dave On Dec 4, 11:44 am, spamTHIS...@yahoo.com wrote: > > In article <fb434613-8353-4312-9fc0-f63502b59...@e6g2000prf.googlegroups.com>, spamTHIS...@yahoo.com wrote: > [quoted text clipped - 26 lines] > I've heard folks say they've heard it works, but haven't found anyone > who says they did it and it helped. > Dave- Can't speak to ABS but it does work in non-ABS. Normal driving rules apply - don't lock up the brakes so I don't see any why ABS would be any different. BTDT more than once. Harry K > Don't need a hill for that, at least in consumer level ABS of ten years > ago. I've heard things have improved but haven't driven a recent car in > snow situation where the ABS kicked in. I drove to work last year where the roads were absolutely clear. Speed limit on this 4 lane road is 50 mph. We're going about 40 due to traffic... Suddenly, brake lights light up in front of me, we slow to about 25 mph. Then all hell broke loose. The roadway became wet. I was in the right lane, and luckily I noticed traction has completely gone away. The whole road was an ice rink for approx 1/4 mile. I pulled onto the shoulder because I could tell the guy behind me was NOT going to stop. I could barely touch my brakes without the ABS kicking in. Suddenly several cars behind me started banging into each other like bumper cars, one car flew up onto the bank to my right, came down in front of me. I was able to come to a stop with ABS, but I'm not sure I would have been able to stop in the same amount of distance and retain control in this situation without them. I would also recommend people "test" them when it's safe to do so (such as in a subdivision) so you know how they will react when they really do kick in. IMO, ABS overall is a good thing, even though it can increase stopping distance under certain conditions. On Dec 4, 12:58 pm, spamTHIS...@yahoo.com wrote: > OK, is this a subaru implementation issue, or an ABS-in-general issue? > [quoted text clipped - 11 lines] > > Dave It's not just Subaru, my last car was an 02 Grand Am and it did the same thing. It is annoying, and I agree with Brent that ABS should not function at low speeds. Then again, clueless fools sliding into parked cars in parking lots would likely double, and we all know requiring training and skill to drive isn't on the agenda... My current vehicle is an manual trans, and I have not had this issue. Perhaps this is because when I brake in a manual the clutch pedal is depressed, removing that little bit of drive from the engine. That would correspond with the neutral theory as well. > On Dec 4, 12:58 pm, spamTHIS...@yahoo.com wrote: > [quoted text clipped - 24 lines] > depressed, removing that little bit of drive from the engine. That > would correspond with the neutral theory as well. In a lot of ABS implementations, ABS activation will cause the (auto) trans to disengage, so I'm not sure why shifting into neutral helps any. nate  Signaturereplace "roosters" with "cox" to reply. http://members.cox.net/njnagel > OK, is this a subaru implementation issue, or an ABS-in-general issue? > > Going down a steep snowy hill, quite slow, car cannot stop due to the > ABS- just cycles and cycles, keeping car moving slow. The subie > knowledgeable say in this situation, it will stop if you put it in > neutral (its an automatic). I wouldn't try that, but in an emergency I might try Park (knowing full well it will destroy the transmission). > This was the kind of snow where if you lock up the tires you dig > through the crud and stop in short order- used to have to do that with > my pickup, and on this car, the e-brake stopped it right quick. > > Overall I am finding the ABS to be a positive, always wondered if > there was a case where it would be a negative. Ayuh, there sure is! In snow country I'd rather not have ABS. In slip conditions when ABS would help you, stab braking (without ABS) gives you most of the same benefit. On Dec 6, 2:46 pm, John David Galt <j...@diogenes.sacramento.ca.us> wrote: > spamTHIS...@yahoo.com wrote: > > OK, is this a subaru implementation issue, or an ABS-in-general issue? [quoted text clipped - 17 lines] > ABS would help you, stab braking (without ABS) gives you most of the > same benefit. I've decided the appropriate response is to ABS brake to below the threshold, then release the brake and lock 'em up, use the Ebrake, or just turn the key off, which kills the ABS (but does not lock the steering). Dave > On Dec 6, 2:46 pm, John David Galt <j...@diogenes.sacramento.ca.us> > wrote: [quoted text clipped - 26 lines] > > Dave I'm in Canada where we get snow from November to April PL:US freezing rain. I'll never again drive a car without 4 wheel disc ABS Traction Control ever again. I have tested my current 2004 Sebring I parking lots at night in the snow learning how the ABS an traction control work. I'm using Michelin Destiny X tires. I had a 98 Alero with 4 wheel disc abs traction but went to a small car in 2001, a Saturn sl1 with NO Abs or Traction control and Rear drums. Back to my current car.... I found that the best way to gain control on this car is to simply hold firmly on the ABS and concentrate all my mental energy on he steering wheel. I can't believe it but I'm trusting my life to a computer. I've never done a test above 60 Km/Hr but I will say that one day not so long ago driving at 130 km/hr we hit black ice on a freeway. I saw numerous cars spin out. I hit the brake pedal firmly and slowed to about 45 km/hr all the while worrying about my air-bad deployment software and never once about braking. Several cars behind me spun out but I never lost straight line control. I saw 2 separate cars hit guard rails and parts fly in the air. 3 other cars hit each other on the left side of my rear-view mirror and even more parts flying in the air. Fenders and bumbers flying in the air in my rear-view mirror. All I did was hold firmly on the brake pedal until I got that 45 km speed that I feel very comfortable with. I've trained myself in this car to concentrate on steering when driving and to leave the computers to do the braking for me. > . >> On Dec 6, 2:46 pm, John David Galt <j...@diogenes.sacramento.ca.us> [quoted text clipped - 60 lines] > I've trained myself in this car to concentrate on steering when > driving and to leave the computers to do the braking for me. The DUMBEST thing to do is to brake while on ice,ABS or not;that is what put all those idiots into spins.Best to keep throttle constant,no fast changes,keep the car straight across the ice,no course changes,no braking,until you're past it. SignatureJim Yanik jyanik at kua.net > > I've never done a test above 60 Km/Hr but I will say that > > one day not so long ago driving at 130 km/hr we hit black ice on a [quoted text clipped - 12 lines] > The DUMBEST thing to do is to brake while on ice,ABS or not;that is what > put all those idiots into spins. Maybe it's just me, but I think his reported experience is going to override your highly questionable conclusion, considering physics and all. A vehicle with essentially no traction is going to continue upon the path it was on when traction was lost. I don't believe most road are sufficiently crowned that they would cause a vehicle to "spin". > Best to keep throttle constant,no fast > changes,keep the car straight across the ice,no course changes,no > braking,until you're past it. And if the vehicle to your front is braking.... or a vehicle wanders into your path? You seem to have assumed no conflicts between vehicle paths will occur (for some reason), and if they do they're irrelevant and a driver shouldn't even lift off the throttle. Have I misinterpreted your advice...? ----- - gpsman > > > I've never done a test above 60 Km/Hr but I will say that > > > one day not so long ago driving at 130 km/hr we hit black ice on a [quoted text clipped - 20 lines] > path it was on when traction was lost. I don't believe most road are > sufficiently crowned that they would cause a vehicle to "spin". You believe wrong. I've driven on roads slick enough where at a minimum it was near impossible to keep the vehicle pointed straight ahead unless straddling the center line. When you're dealing with a layer of slick ice, you coefficient of friction can drop below even 0.1, especially if it's still hard but has a layer of water on top. It's not much of a stretch to conclude that any kind of significant input could put a vehicle into a spin. > > Best to keep throttle constant,no fast > > changes,keep the car straight across the ice,no course changes,no > > braking,until you're past it. > > And if the vehicle to your front is braking.... or a vehicle wanders > into your path? You're screwed. Best hope is to hit the shoulder and maybe get stuck, but at least not hit anything. Of course, if there's loose snow on the shoulder, that will likely stop you faster than the ice anyway. > You seem to have assumed no conflicts between vehicle paths will occur > (for some reason), and if they do they're irrelevant and a driver > shouldn't even lift off the throttle. > > Have I misinterpreted your advice...? Probably. However, the OP's concern seems to be an ABS system that will cut all braking power in a situation where he was able to stop in a non-ABS car without too much drama. My only advice in that situation is "buy a car without ABS" or "buy a car with better ABS." There are some pretty poor ABS implementations out there. I remember having the same issue in an '80s Dodge van; if you hit any ice at all, even patchy, while trying to stop, you... wouldn't. I usually had a choice of a newer van with ABS and an older van without, and whenever I had the option, I always drove the older one. nate > > > > I've never done a test above 60 Km/Hr but I will say that > > > > one day not so long ago driving at 130 km/hr we hit black ice on a [quoted text clipped - 59 lines] > > nate My concern(s) is/are that/those 1/very few situations where the ABS is working against me. 99+% of the time, its a boon. Going down a slick hill where locking the brakes will stop me very quickly, but the ABS keeps me from stopping is one such situation. If the ABS threshold was 15mph that'd be great, I think. It looks to be more like 10 or just below. Dave > If the ABS threshold was 15mph that'd be great, I think. It looks to > be more like 10 or just below. When ABS has 'blanked-out' on me it's been under 5mph I think in all instances, certainly not more than 10mph. I hope by now that if nothing else has been done on 'consumer level' ABS that it just shuts off at such slow speeds. It's not like a 5mph skid is a huge deal. >>If the ABS threshold was 15mph that'd be great, I think. It looks to >>be more like 10 or just below. [quoted text clipped - 3 lines] > else has been done on 'consumer level' ABS that it just shuts off at such > slow speeds. It's not like a 5mph skid is a huge deal. I think most if not all ABS systems work down to about 2-5 MPH. Don't take that to the bank though; I'm sure there's an exception. nate Signaturereplace "roosters" with "cox" to reply. http://members.cox.net/njnagel > > > > I've never done a test above 60 Km/Hr but I will say that > > > > one day not so long ago driving at 130 km/hr we hit black ice on a [quoted text clipped - 24 lines] > minimum it was near impossible to keep the vehicle pointed straight > ahead unless straddling the center line. Of course you have! And of course you attribute your difficulties to the road... > When you're dealing with a > layer of slick ice, you coefficient of friction can drop below even > 0.1, especially if it's still hard but has a layer of water on top. > It's not much of a stretch to conclude that any kind of significant > input could put a vehicle into a spin. Duh. It's a hell of a stretch, especially for someone who professes to be an "engineer". If there ain't no traction no amount of driver input is going to change anything much, so it certainly will not, and can not, induce a "spin". A vehicle is not likely to rotate or change direction or velocity on ice. That's the original and basic problem: driver input is ineffective. So it can't be "more" effective at causing the vehicle to spin than would be to stop. > > > Best to keep throttle constant,no fast > > > changes,keep the car straight across the ice,no course changes,no [quoted text clipped - 6 lines] > but at least not hit anything. Of course, if there's loose snow on > the shoulder, that will likely stop you faster than the ice anyway. Hope... and brace for impact, I presume...? I'm reminded of my favorite scene in "Strange Brew" where Doug loses the brakes going down a hill and finally deciding they're not going to do squat kicks back and crosses his arms and says, "No sense in steerin' now...". > > You seem to have assumed no conflicts between vehicle paths will occur > > (for some reason), and if they do they're irrelevant and a driver > > shouldn't even lift off the throttle. > > However, the OP's concern seems to be <> Thanks, Captain Obvious. That wasn't was I addressed. ----- - gpsman >>>>>I've never done a test above 60 Km/Hr but I will say that >>>>>one day not so long ago driving at 130 km/hr we hit black ice on a [quoted text clipped - 72 lines] > > - gpsman Balls, balls, bullshit and balls. Your statements about a car resisting a spin would be true if all roads were billiard-table smooth. However, all are not, therefore your comments are false. Most roads have a significant enough crown that if enough ice is present, a car will tend to slide off onto the shoulder, no matter what, unless you remain perfectly centered. It is no stretch of the imagination to assume that the front or rear of the car would slide faster, as few cars are perfectly balanced. Therefore a spin is entirely possible if a violent enough input (such as braking or steering) is introduced, although you are correct in one respect, the center of mass of the car will indeed continue to travel on roughly its original path. This has nothing to do with engineering and everything to do with personal experience, sounds like one of us needs to get out and drive on some slick roads before shooting his mouth off. Whoever you were responding to had the right idea; when things are really scary slick, the best thing to do is as little as possible, and to just try to ride it out until you're back on more grippy ground. nate Signaturereplace "roosters" with "cox" to reply. http://members.cox.net/njnagel > >>>>>I've never done a test above 60 Km/Hr but I will say that > >>>>>one day not so long ago driving at 130 km/hr we hit black ice on a [quoted text clipped - 101 lines] > > - Show quoted text - With all the videos out there showing cars going for protracted slides, spins etc with the brakes locked and driver adding no other input, he thinks a car will not 'spin' on glass slick ice! All it takes is a slight differential in friction on one wheel. Then once started it tends to increase vice damp out. Harry K >> The DUMBEST thing to do is to brake while on ice,ABS or not;that is what >> put all those idiots into spins. [quoted text clipped - 6 lines] >path it was on when traction was lost. I don't believe most road are >sufficiently crowned that they would cause a vehicle to "spin". If the road has essentially no traction, the vehicle slides off the road, slowly rotating from the slight difference in when the fronts and the rears break loose. If the road has slightly greater traction, braking (hard) will usually cause a spin. Either condition can exist on an icy road. SignatureThere's no such thing as a free lunch, but certain accounting practices can result in a fully-depreciated one. > ><spamTHIS...@yahoo.com> wrote in message > >news:bd3160fb-3838-4c6f-8088-94ee855afbaf@e6g2000prf.googlegroups.com.. [quoted text clipped - 75 lines] > > - Show quoted text - Yeah, if you can without running into someone ahead. I once entered a long sweeping shaded corner up in New Hampshire in the spring. Just as I entered at 65 I saw the frost. Tighten cheeks, sit lightly on the seat, hold breath and maintain all inputs without wavering. That was a loooong 4 seconds. Harry K >> ><spamTHIS...@yahoo.com> wrote in message >> >news:bd3160fb-3838-4c6f-8088-94ee855afbaf@e6g2000prf.googlegroups.com [quoted text clipped - 85 lines] > > Harry K I used to drive I-65 from the north through downtown Indianapolis to get to work on the East side,and many of the bridges are CURVES;and they all ice over first every winter.And every winter,idiots would brake when they got ON the ice,and immediately spin out. I had a lot of white-knuckle time on I-65. SignatureJim Yanik jyanik at kua.net > >> ><spamTHIS...@yahoo.com> wrote in message > >> >news:bd3160fb-3838-4c6f-8088-94ee855afbaf@e6g2000prf.googlegroups.com [quoted text clipped - 91 lines] > ON the ice,and immediately spin out. I had a lot of white-knuckle time on > I-65. That's odd, I've had the same experience on PA-65 near Monaca. There is (or at least used to be, 20 years ago) a bridge on a curve with some kind of plant with a stack underneath it, so there'd be lots of steam coming out of the stack and freezing on the road surface. So people would come around the curve, realize that they were driving on ice, and slam on the brakes with predictable results. Had at least one wild ride (with my mom driving) when someone did that in front of us and she attempted to steer around him... she missed him, but ended up facing the wrong way on top of the median divider thing. Say what you like about F*rd Pintos, but the darn thing didn't seem to be fazed by the whole experience. And my mom is probably a much better driver in ice and snow than I, having grown up in a far more rural area in a time when pretty much all cars were RWD. Only other time I remember having something like that happen with her driving was when a dog ran out in the street right in front of her... she's too kind to animals. Poor mailbox didn't fare so well though. nate > >> ><spamTHIS...@yahoo.com> wrote in message > >> >news:bd3160fb-3838-4c6f-8088-94ee855afbaf@e6g2000prf.googlegroups.com [quoted text clipped - 91 lines] > ON the ice,and immediately spin out. I had a lot of white-knuckle time on > I-65. That's odd, I've had the same experience on PA-65 near Monaca. There is (or at least used to be, 20 years ago) a bridge on a curve with some kind of plant with a stack underneath it, so there'd be lots of steam coming out of the stack and freezing on the road surface. So people would come around the curve, realize that they were driving on ice, and slam on the brakes with predictable results. Had at least one wild ride (with my mom driving) when someone did that in front of us and she attempted to steer around him... she missed him, but ended up facing the wrong way on top of the median divider thing. Say what you like about F*rd Pintos, but the darn thing didn't seem to be fazed by the whole experience. And my mom is probably a much better driver in ice and snow than I, having grown up in a far more rural area in a time when pretty much all cars were RWD. Only other time I remember having something like that happen with her driving was when a dog ran out in the street right in front of her... she's too kind to animals. Poor mailbox didn't fare so well though. nate > >> ><spamTHIS...@yahoo.com> wrote in message > >> >news:bd3160fb-3838-4c6f-8088-94ee855afbaf@e6g2000prf.googlegroups.com [quoted text clipped - 99 lines] > > - Show quoted text - Another time, another place. I took a temp job as rod-man running level lines for the geological survey. Walked many and many a mile carrying that rod. One morning they decided to get anothe 'run' done. Roads icy and the surveyor told me to drive. Dodge Power Wagon with full load of options. My first time driving a 4x so I set out. No problem as I treated it as just another 2x and took it easy. He had me stop on a corner, did, ritght in the middle of it. No problem until he loaded up again and said go. I was sitting on almost glare ice on a corner with one very steep super. I just _knew_ that the instant I tried to go, it would be slide down into the ditch. He suggested "Put it in 4x". PUT IT IN!! I thought I had been there. Lessone learned. Learn the equipment in a new (to me) rig before driving it. Harry K > > >> ><spamTHIS...@yahoo.com> wrote in message > > >> >news:bd3160fb-3838-4c6f-8088-94ee855afbaf@e6g2000prf.googlegroups.com [quoted text clipped - 117 lines] > > - Show quoted text - So far I've had no problems getting around in my Jeep (shift-on-the- fly 4x4). Since the KC area is getting a nasty ice storm, tomorrow morning's biggest challenge is likely to be just entering the Jeep. That is, provided the ice doesn't bring down the roof of it (went for soft-top). Forecast expects up to 2" ice accumulation. My workplace might be closed as a result. 4x4 is handy in these conditions. I remember back in '88 making a trip to work at the start of a freezing rain event...operating a 1981 Bronco at the time. I merely pulled over, locked the hubs, shifted the transfer case, and continued. I had no problem cruising the Interstate at 40 mph but kept my eye out for the lesser-prepared drivers (days before front-wheel drive) cutting donuts at 20. > So far I've had no problems getting around in my Jeep (shift-on-the- > fly 4x4). Since the KC area is getting a nasty ice storm, tomorrow > morning's biggest challenge is likely to be just entering the Jeep. > That is, provided the ice doesn't bring down the roof of it (went for > soft-top). Forecast expects up to 2" ice accumulation. You probably already know this, but: Whatever you do, don't *touch* the plastic windows until they have thawed from the inside out. Most are smart enough to know not to use a scraper, so the temptation is to whack at the soft top to knock the ice off, but don't do it. It may not be as big a problem with newer materials, but after the vinyl ages and has spent time exposed to the elements, the windows can shatter if it's disturbed while frozen. One of the reasons I prefer the hard top in winter... > My workplace might be closed as a result. > > 4x4 is handy in these conditions. I remember back in '88 making a > trip to work at the start of a freezing rain event...operating a 1981 > Bronco at the time. I merely pulled over, locked the hubs, shifted > the transfer case, and continued. Shift-on-the-fly part-time 4WD is nice, isn't it? :) > I had no problem cruising the > Interstate at 40 mph but kept my eye out for the lesser-prepared > drivers (days before front-wheel drive) cutting donuts at 20. Signature~/Garth |"I believe that it is better to tell the truth than a lie. Almgren | I believe it is better to be free than to be a slave. ******* | And I believe it is better to know than to be ignorant." --H.L. Mencken (1880-1956) > > So far I've had no problems getting around in my Jeep (shift-on-the- > > fly 4x4). Since the KC area is getting a nasty ice storm, tomorrow [quoted text clipped - 23 lines] > > Shift-on-the-fly part-time 4WD is nice, isn't it? :) Auto hubs are even nicer :) ('76 IH Scout II) however trying to select low range with an automatic transmission could prove, um, challenging. (anyone who's ever got "lost in neutral" will know exactly what I'm talking about. In a stickshift, if you get stuck on top of a tooth you just keep a little pressure on the lever and slip the clutch ever so slightly, but with a slushbox, you end up rowing back and forth between R and D until you finally get it to slip in...) And the autolockers wouldn't work in reverse, although IH was kind enough to provide ones that could be manually locked for when you're really trying to get stuck. nate > > I had no problem cruising the > > Interstate at 40 mph but kept my eye out for the lesser-prepared [quoted text clipped - 5 lines] > ******* | And I believe it is better to know than to be ignorant." > --H.L. Mencken (1880-1956) |
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