Catching a skid
Discussion
I was talking to my son over the weekend about car control, he has just been on 2 courses driving armoured cars,don`t ask why because i can`t tell you.
I said that when some one tells you about the time they went into a skid and caught the first move but then it flicked back and "hit the barrier" or what ever they did`nt actually catch the first move, they simply over corrected the skid and lost it.
My point was that in most cases (maybe 90%) a slight loss of traction from the rear does not require that much correction from the driver, as soon as you realise you are skidding from the rear you instinctively back off, so your speed comes down, this is usually enough to bring the rear back in line.
If you automaticaly turn into the skid you will probably over do it because backing off the throttle is IMO enough.
He said he would always turn into a skid no matter how slight it was, we were`nt that far apart and each skid is different but it made me wonder what other drivers thought about correcting and over correcting skids.
I remember reading on here were a guy got tipped from behind into a skid on dry tarmac, he turned into it and ended up T-boning the cental crash barrier.
I know that big slides require plenty of imput but alot of skids are like i said slight and its these skids we were talking about.
What do think?
I said that when some one tells you about the time they went into a skid and caught the first move but then it flicked back and "hit the barrier" or what ever they did`nt actually catch the first move, they simply over corrected the skid and lost it.
My point was that in most cases (maybe 90%) a slight loss of traction from the rear does not require that much correction from the driver, as soon as you realise you are skidding from the rear you instinctively back off, so your speed comes down, this is usually enough to bring the rear back in line.
If you automaticaly turn into the skid you will probably over do it because backing off the throttle is IMO enough.
He said he would always turn into a skid no matter how slight it was, we were`nt that far apart and each skid is different but it made me wonder what other drivers thought about correcting and over correcting skids.
I remember reading on here were a guy got tipped from behind into a skid on dry tarmac, he turned into it and ended up T-boning the cental crash barrier.
I know that big slides require plenty of imput but alot of skids are like i said slight and its these skids we were talking about.
What do think?
Lost it, they didn't steer quick enough probably, you've got to pre-empt it & no time for niceties with the steering either.
Steering into it & braking with ABS will bring it into line quickly, but the car will go where the nose is pointing at the time you brake. I'm talking about where you have reasonably grippy surface here & you have provoked oversteer simply through sharp steering movements in order to avoid something.
There are a multitude of different scenarios & different inputs to deal with each. Depends on the room you have & circumstances of course, but I prefer for smaller amounts of oversteer to use a small amount of steering into it & a little throttle, then gently taking steering off with the throttle bringing it into line.
Of course using your skill to make sure you don't get into a skid is preferable to using it to get you out of one.
Steering into it & braking with ABS will bring it into line quickly, but the car will go where the nose is pointing at the time you brake. I'm talking about where you have reasonably grippy surface here & you have provoked oversteer simply through sharp steering movements in order to avoid something.
There are a multitude of different scenarios & different inputs to deal with each. Depends on the room you have & circumstances of course, but I prefer for smaller amounts of oversteer to use a small amount of steering into it & a little throttle, then gently taking steering off with the throttle bringing it into line.
Of course using your skill to make sure you don't get into a skid is preferable to using it to get you out of one.
Edited by vonhosen on Monday 12th June 22:56
Hairy Don P talks about allowing the car to respond before adding more inputs.
As Von says - catching it early, ugly and plenty is the way to respond, but then allowing the system to respond and settle before adding a lot more inputs that throw you off again. This helps to avoid the fishtailing and over-correcting that turn a skid into a total loss of control.
I think skid pans are a giggle so well worth getting time on one if possible.
As Von says - catching it early, ugly and plenty is the way to respond, but then allowing the system to respond and settle before adding a lot more inputs that throw you off again. This helps to avoid the fishtailing and over-correcting that turn a skid into a total loss of control.
I think skid pans are a giggle so well worth getting time on one if possible.
I`m going to take the fifth emendment here but the firm i work for has enabled me to put into practice my theories about driving, i soon realised that if the car goes into a skid,ie, loss of grip the car will go were its pointing when the grip returns which uaually happens when either the speed comes down or the surface improves.
When the police came up with this idea that when a car goes into a skid you should dip your clutch i could see how that would work, after all sudden changes from the drive axle be it front or rear can send you into a spin so dipping your clutch makes good sense.
But it seemed that too many people were going into skids and "over correcting them" they thought they had caught the first skid but were`nt quick enough to catch the rebound skid.
If you make no attempt to catch the skid (as long as it only slight) you will lift of the gas, it will slow down, you will get grip back, then you fire off were ever the car is pointing so too much steering will send you the opposite way you thought you were going to go.
As it happens my son is booked to go on a skid course so i`ll be keen to hear what he has to say.
Don`t get me wrong i`m no expert, i think i`v been very lucky and i`m glad to hear anyone elses comment on the subject.
When the police came up with this idea that when a car goes into a skid you should dip your clutch i could see how that would work, after all sudden changes from the drive axle be it front or rear can send you into a spin so dipping your clutch makes good sense.
But it seemed that too many people were going into skids and "over correcting them" they thought they had caught the first skid but were`nt quick enough to catch the rebound skid.
If you make no attempt to catch the skid (as long as it only slight) you will lift of the gas, it will slow down, you will get grip back, then you fire off were ever the car is pointing so too much steering will send you the opposite way you thought you were going to go.
As it happens my son is booked to go on a skid course so i`ll be keen to hear what he has to say.
Don`t get me wrong i`m no expert, i think i`v been very lucky and i`m glad to hear anyone elses comment on the subject.
It totally depends on why the back has lost grip.
In the case of power oversteer (say, on the exit of a bend when you've been too aggressive on the throttle), then backing off slightly will reduce the speed of the rear wheels and you will probably be able to restore grip.
On the other hand, if the back has lost grip because you were braking with a bit of steering lock on, then easing the throttle will cause weight to shift towards the front. This will exacerbate, not remedy, the oversteer.
This cause of oversteer is particularly common when you are coming over a crest, and the back end is going to get lighter anyhow.
If you go over a bending crest and brake at the top of it, there is a serious likelihood that the rear end will come around, and in this case you will want to add throttle to stabilise the car.
It's generally better to stay on the throttle in either case and use the steering wheel to sort yourself out. An early, quick correction with a light touch (despite the tendency to grip the wheel harder) is always better than a later, more dramatic correction. Remember that it is essential to look towards where you want the car to go, not towards where it is wrongly going.
If you realise that you're overcorrecting and that you are just making things worse, often letting go entirely of the steering wheel will quickly stabilise the situation. You may laugh, but I promise you that it will work in many circumstances.
In the case of power oversteer (say, on the exit of a bend when you've been too aggressive on the throttle), then backing off slightly will reduce the speed of the rear wheels and you will probably be able to restore grip.
On the other hand, if the back has lost grip because you were braking with a bit of steering lock on, then easing the throttle will cause weight to shift towards the front. This will exacerbate, not remedy, the oversteer.
This cause of oversteer is particularly common when you are coming over a crest, and the back end is going to get lighter anyhow.
If you go over a bending crest and brake at the top of it, there is a serious likelihood that the rear end will come around, and in this case you will want to add throttle to stabilise the car.
It's generally better to stay on the throttle in either case and use the steering wheel to sort yourself out. An early, quick correction with a light touch (despite the tendency to grip the wheel harder) is always better than a later, more dramatic correction. Remember that it is essential to look towards where you want the car to go, not towards where it is wrongly going.
If you realise that you're overcorrecting and that you are just making things worse, often letting go entirely of the steering wheel will quickly stabilise the situation. You may laugh, but I promise you that it will work in many circumstances.
I guess the armoured cars are rear wheel drive?
Oversteer slides are a lot like swinging a pendulum. The initial cause of the slide pushes the back of the car sideways, and the challenge is to get it back to the center and stopped as soon as possible. Once the driver counteracts the cause of the slide the pendulum slows down, stops, and starts to swing back towards the center. If the driver removes the correction as quickly as they applied it, it'll naturally overshoot and travel a similar distance the other way, and keep going back and forth until the momentum gradually dissipates, or it hits something.
If the driver is slow to respond, the effects of the correction lag behind the movement of the car and the swings get bigger and bigger, just like pumping a swing by swinging your legs at the right time. To stop the pendulum effect the driver has to anticipate the movement of the car, add the correction faster than it swings out and remove it faster than it swings back. Not so hard in the dry when relatively little correction may be required, but much harder in the wet when much more correction is required.
It doesn't take much training to catch a small slide, but catching the rebound takes a lot more skill. Have you noticed how many cars go off on the outside just after a corner?
Oversteer slides are a lot like swinging a pendulum. The initial cause of the slide pushes the back of the car sideways, and the challenge is to get it back to the center and stopped as soon as possible. Once the driver counteracts the cause of the slide the pendulum slows down, stops, and starts to swing back towards the center. If the driver removes the correction as quickly as they applied it, it'll naturally overshoot and travel a similar distance the other way, and keep going back and forth until the momentum gradually dissipates, or it hits something.
If the driver is slow to respond, the effects of the correction lag behind the movement of the car and the swings get bigger and bigger, just like pumping a swing by swinging your legs at the right time. To stop the pendulum effect the driver has to anticipate the movement of the car, add the correction faster than it swings out and remove it faster than it swings back. Not so hard in the dry when relatively little correction may be required, but much harder in the wet when much more correction is required.
It doesn't take much training to catch a small slide, but catching the rebound takes a lot more skill. Have you noticed how many cars go off on the outside just after a corner?
I think it depends on the circumstances and the nature of the car you are driving. On most of the rear wheel drive cars I've owned, (and particularly my current car, Cerb), suddenly coming off the gas upsets the balance and can cause the car to fishtail. I only throttle off if I'm coming out of a bend and start to get a twitch under acceleration.
If entering a corner fast I think it is better to straighten the steering gently and feel how the car responds, if it isn't tending to feel as though it's prepared to turn in, gently apply the lock until it feels as though it is whilst maintaining an even throttle. If the car is sliding prepare to gently repeat to centre as the balance transfers.
I'm sure many opinions will differ but I guess it's what works for each driver.
If entering a corner fast I think it is better to straighten the steering gently and feel how the car responds, if it isn't tending to feel as though it's prepared to turn in, gently apply the lock until it feels as though it is whilst maintaining an even throttle. If the car is sliding prepare to gently repeat to centre as the balance transfers.
I'm sure many opinions will differ but I guess it's what works for each driver.
A little anecdote from my two real-world oversteer experiences (back when I was a newish driver, inexperienced, adventurous, and minimally trained):
Scenario one:
Wet country road, driving a heavy Merc 8-cylinder, auto-tranny. Exit oversteer on a tight left-hand junction, opening to a narrow two-way road (cliff-face on one side, downhill embankment opposite side). Instinctively backed off the gas to about 1/4 throttle, opposite lock. Car drifted steadily for a moment, then sharply switched back, which caught me unawares and flailing for opposite lock again. Held another steady drift, but creeping toward opposite side of road toward oncoming vehicle! Played with the throttle to find grip at the rear and gradually unwound steering as I found it. Car swung around again, but a quick touch of slight opposite lock brought it back into line and safety.
Scenario two:
Remote dirt road, moderate right-hand bend, driving an old Volvo - locked diffs and auto tranny. Nightmare of a car to handle.
Mid-corner oversteer, which was corrected by a small amount of opposite steering. No big deal?
Exit oversteer, but couldn't figure out why. Opposite lock, but the the car kept pivoting around, and then very suddenly switched to the other direction. Struggled for opposite lock again, but couldn't steady it. Car switches back abruptly again. Went for another armful of opposite lock, but again, couldn't steady the drift. Car switches back in the other direction, another attempt at opposite lock. Finally the drift becomes steady, but the car was creeping rapidly toward an embankment (only around a metre away). Decided to stand on the brakes, rather than risk another fishtail. Brought it to a stop about a foot away from the embankment.
Moral of the two scenarios above (for RWD of course):
1. Look in the direction where you want to go.
2. Apply opposite lock, according to where you want to go.
3. Give time for skid to steady.
4. Once the skid has been stablised (ie. the car is no longer yawing), massage the throttle to find grip, and progressively centre the steering wheel in anticipation for counter-skid.
5. If the skid cannot be made steady, take pre-emptive action and get on the brakes. Attempt to lock all wheel and bring the car to a halt.
If there is a clutch, it would probably be a good idea to press it. Easier than trying to find the right amount of throttle.
Of course, prevention is always better than cure, and anticipation negates reaction time. Drive smoothly and steadily enough to not get into a skid, and gain enough experience in handling your car at the limit to be able to anticipate its behaviour when it goes over.
But, as I said in another thread, its one thing to recovery from a skid in the sterile environment of a skid pan, but totally another to try it in the real world when you're not expecting it and the conditions are not regulated.
Scenario one:
Wet country road, driving a heavy Merc 8-cylinder, auto-tranny. Exit oversteer on a tight left-hand junction, opening to a narrow two-way road (cliff-face on one side, downhill embankment opposite side). Instinctively backed off the gas to about 1/4 throttle, opposite lock. Car drifted steadily for a moment, then sharply switched back, which caught me unawares and flailing for opposite lock again. Held another steady drift, but creeping toward opposite side of road toward oncoming vehicle! Played with the throttle to find grip at the rear and gradually unwound steering as I found it. Car swung around again, but a quick touch of slight opposite lock brought it back into line and safety.
Scenario two:
Remote dirt road, moderate right-hand bend, driving an old Volvo - locked diffs and auto tranny. Nightmare of a car to handle.
Mid-corner oversteer, which was corrected by a small amount of opposite steering. No big deal?
Exit oversteer, but couldn't figure out why. Opposite lock, but the the car kept pivoting around, and then very suddenly switched to the other direction. Struggled for opposite lock again, but couldn't steady it. Car switches back abruptly again. Went for another armful of opposite lock, but again, couldn't steady the drift. Car switches back in the other direction, another attempt at opposite lock. Finally the drift becomes steady, but the car was creeping rapidly toward an embankment (only around a metre away). Decided to stand on the brakes, rather than risk another fishtail. Brought it to a stop about a foot away from the embankment.
Moral of the two scenarios above (for RWD of course):
1. Look in the direction where you want to go.
2. Apply opposite lock, according to where you want to go.
3. Give time for skid to steady.
4. Once the skid has been stablised (ie. the car is no longer yawing), massage the throttle to find grip, and progressively centre the steering wheel in anticipation for counter-skid.
5. If the skid cannot be made steady, take pre-emptive action and get on the brakes. Attempt to lock all wheel and bring the car to a halt.
If there is a clutch, it would probably be a good idea to press it. Easier than trying to find the right amount of throttle.
Of course, prevention is always better than cure, and anticipation negates reaction time. Drive smoothly and steadily enough to not get into a skid, and gain enough experience in handling your car at the limit to be able to anticipate its behaviour when it goes over.
But, as I said in another thread, its one thing to recovery from a skid in the sterile environment of a skid pan, but totally another to try it in the real world when you're not expecting it and the conditions are not regulated.
Edited by Jungles on Tuesday 13th June 01:57
...and then theres 4wd, which is another thing altogether. see:
www.pistonheads.com/gassing/topic.asp?t=276155&f=123&h=0
for a story. any inspired thoughts about that one that hasn't been mentioned there?
general recovery mode for 4wd is to keep the right foot planted and point the front wheels where you want to go, most often they jsut pull themselves out of the slide. which could be applicable to armoured cars if they happen to be 4wd.
www.pistonheads.com/gassing/topic.asp?t=276155&f=123&h=0
for a story. any inspired thoughts about that one that hasn't been mentioned there?
general recovery mode for 4wd is to keep the right foot planted and point the front wheels where you want to go, most often they jsut pull themselves out of the slide. which could be applicable to armoured cars if they happen to be 4wd.
For most skids - undoing what you just did is the right answer. Hardest is front wheel skid, where what you just did was add deflection (presumably to avoid something), so it's about steering back towards the thing you are avoiding rather than adding more to overcome the apparent understeer...
A minor point but one worth making is this:
When having a circuit lesson and the car started to skid (in this case FWD but the point is equally valid) the most important thing is to be SMOOTH! If you are going to back off the throttle, do it gently. I was "Shutting" the throttle which only serves to upset the car more. It takes practice, because the first real skid you $h1t yourself, then with familiarity you learn to expect them and then control them
Keep your inputs smooth.
Cheers,
Steve.
When having a circuit lesson and the car started to skid (in this case FWD but the point is equally valid) the most important thing is to be SMOOTH! If you are going to back off the throttle, do it gently. I was "Shutting" the throttle which only serves to upset the car more. It takes practice, because the first real skid you $h1t yourself, then with familiarity you learn to expect them and then control them
Keep your inputs smooth.
Cheers,
Steve.
Fat Audi 80 said:
I was "Shutting" the throttle which only serves to upset the car more.
That's an important point. The aim is to correct the skid by removing tha cause i.e. yaw instability caused by excessive power to the rear wheels. The ideal way to achieve this is to drop the wheel speed back to the road speed and then applied a very small amount of power, this puts the car in the most stable situation, encourages understeer and discourages oversteer. If you go further than that and apply engine braking things get a LOT worse, because engine braking destabilises the car far more than excessive power does. Dipping the clutch is a good way to ensure that you don't apply engine braking by mistake, but it makes it that much harder to reapply power after you have caught the initial slide, and applying power is a useful technique to damp out the rebound. So dipping the clutch is a good starting point until you learn how to regain control of the car, but once you've learned enough to survive the initial crisis you will probably want to learn to cope with the clutch engaged.
I went into a skid many years ago that had a good result, i`d like to think it was a mixture of skill and luck.
The road itself may have changed now (it was about 15 years ago) but if you leave the M6 south bound at J1 and turn right, go 1 mile then turn left, its pretty straight down hill then it bottoms out and turns left at 90 degrees.
I was in a 2 ltr RWD soft suspension car as i got to the bottom of the hill intending to late brake the corner the road went from dry to wet due to water running off a field to my left(Oh dear).
The suspension went down as the road bottomed out, then the car went light just as i decided to brake, the front might have locked at this stage but the rear certainly did i could hear it and feel the rear end trying to come round on my right, i suddenly saw white 2 foot posts on the outside edge of the bend protecting what looked like a soft grass verge.
As i tried to turn into the left turn i realised my front wheels were locked up so i eased off and tried again, i was trying to do 3 things at once.
Lose speed(by doing some braking).
Get round the left turn.
Catch the slide.
I distinctly remember not trying 100% to correct the slide this was because the vehicle seemed to be wanting to actually go round the corner, the headlights were shinning that way and as i was losing speed it started to go more were it was pointing and less for the white posts.
If something had been coming round the corner i would have clobbered them with my rear right corner, but as it happened i came to a stop completely round the bend (please don`t say it) with my front 2 wheels 12 inches on the nearside grass verge....Phew.
I reversed off the grass then made a quick exit, it was not clever and it was not funny, i just hope i never meet someone doing that when i`m coming the other way.
Please remember i was younger then and never drive like that now(my wife won`t let me).
The road itself may have changed now (it was about 15 years ago) but if you leave the M6 south bound at J1 and turn right, go 1 mile then turn left, its pretty straight down hill then it bottoms out and turns left at 90 degrees.
I was in a 2 ltr RWD soft suspension car as i got to the bottom of the hill intending to late brake the corner the road went from dry to wet due to water running off a field to my left(Oh dear).
The suspension went down as the road bottomed out, then the car went light just as i decided to brake, the front might have locked at this stage but the rear certainly did i could hear it and feel the rear end trying to come round on my right, i suddenly saw white 2 foot posts on the outside edge of the bend protecting what looked like a soft grass verge.
As i tried to turn into the left turn i realised my front wheels were locked up so i eased off and tried again, i was trying to do 3 things at once.
Lose speed(by doing some braking).
Get round the left turn.
Catch the slide.
I distinctly remember not trying 100% to correct the slide this was because the vehicle seemed to be wanting to actually go round the corner, the headlights were shinning that way and as i was losing speed it started to go more were it was pointing and less for the white posts.
If something had been coming round the corner i would have clobbered them with my rear right corner, but as it happened i came to a stop completely round the bend (please don`t say it) with my front 2 wheels 12 inches on the nearside grass verge....Phew.
I reversed off the grass then made a quick exit, it was not clever and it was not funny, i just hope i never meet someone doing that when i`m coming the other way.
Please remember i was younger then and never drive like that now(my wife won`t let me).
If you ever get the chance, practice is the key. If you have to think too much about what you are about to do, the chances are you will have already reached the scene of the accident. Flemke's suggestion of letting go, can at times can be more effective than you could imagine. I'm no expert, just speak from 25 years of getting away with it by the skin of my teeth!!
do80 said:
If you ever get the chance, practice is the key. If you have to think too much about what you are about to do, the chances are you will have already reached the scene of the accident. Flemke's suggestion of letting go, can at times can be more effective than you could imagine. I'm no expert, just speak from 25 years of getting away with it by the skin of my teeth!!
Go Karts!!
micky g said:
Go Karts!!
Good call, they teach real car control. I did try to qualify on slicks on a (just) drying circuit once, hoping for a dry line, (trying to be clever as everyone was on wets), 4th gear, big moment, lots of grass, sit tight and wait for the tyre wall etc,etc... The one I didn't get away with!
Now if I'd learned in a kart....who knows!
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