What's your left foot doing during a skid ??
10 January 2007, 10:20 AM
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What's your left foot doing during a skid ??
About 10 years ago I went on an afternoon long skidpan course. We used an old rwd Sierra. The instructor explained to us that when the car started to skid we should depress the clutch fully and (of course) steer into the skid. This seemed to work pretty well.
Now, with an Impreza, by depressing your clutch you are losing the advantage of 4wd. So should your foot go anywhere near the clutch when controlling a skid ?
And, if you don't use the clutch, do you simply keep the same pressure on the accelerator ?
Now, with an Impreza, by depressing your clutch you are losing the advantage of 4wd. So should your foot go anywhere near the clutch when controlling a skid ?
And, if you don't use the clutch, do you simply keep the same pressure on the accelerator ?
10 January 2007, 10:26 AM
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10 January 2007, 10:30 AM
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what lift the throttle mid way??
im only just gettin used to it sliding out occasionly,
live in the middle of knowhere, u come out onto a road about 15-20m wide and no one really about i pull out the junction at high revs and **** slides out nicely and straitens up!
im only just gettin used to it sliding out occasionly,
live in the middle of knowhere, u come out onto a road about 15-20m wide and no one really about i pull out the junction at high revs and **** slides out nicely and straitens up!
10 January 2007, 10:33 AM
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Four wheel skid:
Characteristics
All four wheels have locked up and the vehicle is sliding in the direction that the forward momentum is carrying it, with no directional control; see figure 3. It should be noted that both front and rear wheel skids, if unchecked sufficiently early, can develop into four wheel skids.
Cause
Harsh or sudden braking has caused the wheels to lock. A sensation of increase in the vehicle’s speed often occurs.
Remedy
To achieve directional control, depress the clutch and rhythmically pump the brake pedal (cadence braking). This allows the brakes to lock and unlock. While they are unlocked, any movement of the steering wheel will have a positive effect. This is basically the same principle that ABS braking systems work on.
Rear Wheel Skid:
Characteristics
The rear of vehicle swings out of line and gives the impression of trying to overtake the front (oversteer); see figure 2.
Cause
As with the front wheel skid, excessive speed into the hazard and sudden braking or acceleration with a rear wheel drive vehicle, destabilising the vehicle, are the main causes of this skid.
Remedy
Again take the right foot off the accelerator or brake and depress the clutch, then steer in the direction that the back of the vehicle is sliding (steer into the skid). Beware of correcting the steering too much as this may cause the vehicle to slide back in the opposite direction. As with the front wheel skid, these actions should be simultaneous, to prevent the back of the vehicle from building up too much momentum and sliding out of control.
Front Wheel Skid:
Characteristics
The car tends to take a course outside of the expected course that the driver has steered (understeer); see figure 1.
Cause
Excess speed on entry to a hazard i.e. a corner or bend, or sudden braking to reduce the speed when negotiating the hazard. Both of these actions will have the effect of destabilising the vehicle making it more vulnerable to a loss of control.
Remedy
The inclination is to turn the steering wheel further to counteract the understeer. Should adhesion to the road surface be just within the limits, then adding a little more steering may be enough to counter the problem. If not, remove the cause by taking the right foot off the brake or accelerator pedal and fully depressing the clutch pedal, and if necessary reduce some of the steering; these actions should be simultaneous. The vehicle should now start regaining traction, but be prepared for the steering to “******” when the vehicle gets back onto a less slippery surface. If the loss of control is exceptionally severe, then following the above action plus straightening the steering momentarily, to allow the front wheels to regain traction, and then steering gently back onto the original course will help to regain control.
Characteristics
All four wheels have locked up and the vehicle is sliding in the direction that the forward momentum is carrying it, with no directional control; see figure 3. It should be noted that both front and rear wheel skids, if unchecked sufficiently early, can develop into four wheel skids.
Cause
Harsh or sudden braking has caused the wheels to lock. A sensation of increase in the vehicle’s speed often occurs.
Remedy
To achieve directional control, depress the clutch and rhythmically pump the brake pedal (cadence braking). This allows the brakes to lock and unlock. While they are unlocked, any movement of the steering wheel will have a positive effect. This is basically the same principle that ABS braking systems work on.
Rear Wheel Skid:
Characteristics
The rear of vehicle swings out of line and gives the impression of trying to overtake the front (oversteer); see figure 2.
Cause
As with the front wheel skid, excessive speed into the hazard and sudden braking or acceleration with a rear wheel drive vehicle, destabilising the vehicle, are the main causes of this skid.
Remedy
Again take the right foot off the accelerator or brake and depress the clutch, then steer in the direction that the back of the vehicle is sliding (steer into the skid). Beware of correcting the steering too much as this may cause the vehicle to slide back in the opposite direction. As with the front wheel skid, these actions should be simultaneous, to prevent the back of the vehicle from building up too much momentum and sliding out of control.
Front Wheel Skid:
Characteristics
The car tends to take a course outside of the expected course that the driver has steered (understeer); see figure 1.
Cause
Excess speed on entry to a hazard i.e. a corner or bend, or sudden braking to reduce the speed when negotiating the hazard. Both of these actions will have the effect of destabilising the vehicle making it more vulnerable to a loss of control.
Remedy
The inclination is to turn the steering wheel further to counteract the understeer. Should adhesion to the road surface be just within the limits, then adding a little more steering may be enough to counter the problem. If not, remove the cause by taking the right foot off the brake or accelerator pedal and fully depressing the clutch pedal, and if necessary reduce some of the steering; these actions should be simultaneous. The vehicle should now start regaining traction, but be prepared for the steering to “******” when the vehicle gets back onto a less slippery surface. If the loss of control is exceptionally severe, then following the above action plus straightening the steering momentarily, to allow the front wheels to regain traction, and then steering gently back onto the original course will help to regain control.
lift off oversteer not good really as not much control as with the throttle...
10 January 2007, 10:35 AM
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Why do these actions:
In each case the cause can be removed by taking the foot off the accelerator or brake and depressing the clutch. The reasons are as follows:-
By decelerating, the vehicle’s speed is lowered, which in turn will start to reduce the magnitude of the skid.
Relaxation of the pressure on the brake pedal will unlock the wheels and allow the tyres to regain traction, enabling the vehicle to be steered.
Depressing the clutch pedal has 3 beneficial effects:
The engine will not stall, enabling the vehicle to be moved quickly from the danger area.
The link between engine (providing power) and transmission is broken; there is no drive to any of the wheels, therefore the vehicle is no longer a front, rear or four wheel drive model.
A very slippery surface can cause the drive to lock up which in turn causes the wheels to lock, keeping the vehicle in a skid situation.
In each case the cause can be removed by taking the foot off the accelerator or brake and depressing the clutch. The reasons are as follows:-
By decelerating, the vehicle’s speed is lowered, which in turn will start to reduce the magnitude of the skid.
Relaxation of the pressure on the brake pedal will unlock the wheels and allow the tyres to regain traction, enabling the vehicle to be steered.
Depressing the clutch pedal has 3 beneficial effects:
The engine will not stall, enabling the vehicle to be moved quickly from the danger area.
The link between engine (providing power) and transmission is broken; there is no drive to any of the wheels, therefore the vehicle is no longer a front, rear or four wheel drive model.
A very slippery surface can cause the drive to lock up which in turn causes the wheels to lock, keeping the vehicle in a skid situation.
10 January 2007, 10:59 AM
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Why do these actions:
In each case the cause can be removed by taking the foot off the accelerator or brake and depressing the clutch. The reasons are as follows:-
By decelerating, the vehicle’s speed is lowered, which in turn will start to reduce the magnitude of the skid.
Relaxation of the pressure on the brake pedal will unlock the wheels and allow the tyres to regain traction, enabling the vehicle to be steered.
Depressing the clutch pedal has 3 beneficial effects:
The engine will not stall, enabling the vehicle to be moved quickly from the danger area.
The link between engine (providing power) and transmission is broken; there is no drive to any of the wheels, therefore the vehicle is no longer a front, rear or four wheel drive model.
A very slippery surface can cause the drive to lock up which in turn causes the wheels to lock, keeping the vehicle in a skid situation.
In each case the cause can be removed by taking the foot off the accelerator or brake and depressing the clutch. The reasons are as follows:-
By decelerating, the vehicle’s speed is lowered, which in turn will start to reduce the magnitude of the skid.
Relaxation of the pressure on the brake pedal will unlock the wheels and allow the tyres to regain traction, enabling the vehicle to be steered.
Depressing the clutch pedal has 3 beneficial effects:
The engine will not stall, enabling the vehicle to be moved quickly from the danger area.
The link between engine (providing power) and transmission is broken; there is no drive to any of the wheels, therefore the vehicle is no longer a front, rear or four wheel drive model.
A very slippery surface can cause the drive to lock up which in turn causes the wheels to lock, keeping the vehicle in a skid situation.
10 January 2007, 11:16 AM
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I can see the benefit of dipping the clutch on a rwd car as the very last thing to do when everything else has failed and you are going to spin but I'm definately not an advocate of it being the first thing to do at all.
Removing the cause should be the first thing to do, be that coming off the brakes or throttle but these actions should be balanced ie don't fully close the throttle. As most people can't do that accurately as they've no experience of how to do it successfully then the best advice may well be to dip the clutch.
This is also why some people have this fear of Imprezas being difficult to control. If you get it sideways and close the throttle ot will feel like it's going to spin. Either opening the throttle slightly or pressing the brakes (if you have ABS) will stop a spin but won't necessarily stop the oversteer. A good example would be driving round a roundabout quite quickly and someone pulls out on you. Lifting the throttle would cause oversteer if near the limit of grip but pressing the brakes will just settle the car down and stop it spinning and you'll just need some corrective lock on.
Experience of how to balance the car on the skid-pad is ideal for this. Some years ago I did the same sort of course with my wife, by the end of it she was using the throttle to provoke and hold proper slides in the old sierra and never once had to dip the clutch to regain control.
Mike
Removing the cause should be the first thing to do, be that coming off the brakes or throttle but these actions should be balanced ie don't fully close the throttle. As most people can't do that accurately as they've no experience of how to do it successfully then the best advice may well be to dip the clutch.
This is also why some people have this fear of Imprezas being difficult to control. If you get it sideways and close the throttle ot will feel like it's going to spin. Either opening the throttle slightly or pressing the brakes (if you have ABS) will stop a spin but won't necessarily stop the oversteer. A good example would be driving round a roundabout quite quickly and someone pulls out on you. Lifting the throttle would cause oversteer if near the limit of grip but pressing the brakes will just settle the car down and stop it spinning and you'll just need some corrective lock on.
Experience of how to balance the car on the skid-pad is ideal for this. Some years ago I did the same sort of course with my wife, by the end of it she was using the throttle to provoke and hold proper slides in the old sierra and never once had to dip the clutch to regain control.
Mike
10 January 2007, 01:01 PM
#19
I look at it as if there is a ´skid´ it means too much is being asked from a tyre and USUALLY this means that the weight is not evenly distributed. My first objective is to get the car back into what I would call a nutural state - a balanced state and as metioned this is all about taking the cause away using the stearing and the throttle.
But if you do this too agressively-then you are just solving one problem and then chucking the weight into another wrong place and creating another problem. So for me the key is all about being gentle and delicate with the controls. Even if you think its going **** up - stay calm - use gentle stearing inputs (I pretend the stearing wheel is made of glass LOL) - dont lift of quickly - gently lift of the throttle partialy.
I think the big problem with Power Overstear - is knowing when to take the opposite lock off. And this only comes with getting a feel for your particular car in an overstear situation - getting it right a few times getting it wrong a few times - which isnt often possible or safe on the roads today.
A few years back I had a rear tyre blow on me at about 100mph in a RWD car and was chucked into quite a sevear overstear situation. It was touch and go for a few seconds as wheather I was going to hold it - as well as doing the above and treating the thing with kid gloves to try and get it balanced. The first thing I did was ditch the clutch to take all power away from the driven wheels. So Andy I say from experience that dipping the clutch definately did the job in this situation
Hope this helps a bit
Steve
But if you do this too agressively-then you are just solving one problem and then chucking the weight into another wrong place and creating another problem. So for me the key is all about being gentle and delicate with the controls. Even if you think its going **** up - stay calm - use gentle stearing inputs (I pretend the stearing wheel is made of glass LOL) - dont lift of quickly - gently lift of the throttle partialy.
I think the big problem with Power Overstear - is knowing when to take the opposite lock off. And this only comes with getting a feel for your particular car in an overstear situation - getting it right a few times getting it wrong a few times - which isnt often possible or safe on the roads today.
A few years back I had a rear tyre blow on me at about 100mph in a RWD car and was chucked into quite a sevear overstear situation. It was touch and go for a few seconds as wheather I was going to hold it - as well as doing the above and treating the thing with kid gloves to try and get it balanced. The first thing I did was ditch the clutch to take all power away from the driven wheels. So Andy I say from experience that dipping the clutch definately did the job in this situation
Hope this helps a bit
Steve
12 January 2007, 12:22 AM
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you are more likely to lose the front of these 4wd performance cars than the rear..unless you do the old scsandinavian flick to get the **** out !!!!!
12 January 2007, 06:25 PM
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I thought that if you come off the throttle or dip the clutch when the back is sliding the angle of the slide will increase beacuse:
1, When you come off the throttle or dip the clutch the weight of the car will transfer frowards.
2, This will remove weight from over the rear wheels
3, This will cause the tyres to loose grip and the slide will increase.
I am an advocate of slightly less throttle, but shutting it completely or removing drive from the sliding wheels will make it worse IMO
Damo
1, When you come off the throttle or dip the clutch the weight of the car will transfer frowards.
2, This will remove weight from over the rear wheels
3, This will cause the tyres to loose grip and the slide will increase.
I am an advocate of slightly less throttle, but shutting it completely or removing drive from the sliding wheels will make it worse IMO
Damo
13 January 2007, 03:44 PM
#24
I thought that if you come off the throttle or dip the clutch when the back is sliding the angle of the slide will increase beacuse:
1, When you come off the throttle or dip the clutch the weight of the car will transfer frowards.
2, This will remove weight from over the rear wheels
3, This will cause the tyres to loose grip and the slide will increase.
I am an advocate of slightly less throttle, but shutting it completely or removing drive from the sliding wheels will make it worse IMO
Damo
1, When you come off the throttle or dip the clutch the weight of the car will transfer frowards.
2, This will remove weight from over the rear wheels
3, This will cause the tyres to loose grip and the slide will increase.
I am an advocate of slightly less throttle, but shutting it completely or removing drive from the sliding wheels will make it worse IMO
Damo
The reason why the backs go is because the tyre has no more grip longitudinaly (Acellerative - decellerative) or laterally (cornering grip).
So you have to get a bit more grip back one way or another back into the tyre.
So you need to take part of the problem away - taking drive away from the rear wheels to get more some more longitudinal grip back into the rear tyres, so you have some level of controll again. When you dip the clutch - what happens is you take drive away from the rear wheels and of course get some grip back in the tyre. This is also a good way to balance the car up for a second or so and get it back to that neutral state. You dont get the huge weight transfer to the front through engine breaking like you would if you lifted off suddenly.
Steve
29 January 2007, 08:57 AM
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First of all, dipping the clutch will not transfer weight to the front anywhere near the same as lifting off the throttle and so should not be dismissed. The reason you get weight transfer is due to acceleration or deceleration. Removing all power simply allows the car to slow down in its own time.
The clutch should not be dipped as a first resort.
If through the sequence of the slide (oversteer) you run out of steering lock, lifting off the throttle (even gently) can aggravate the situation and so if you dip the clutch you remove all internal influences from the wheels. As a result, you give them maximum chance to regrip the road surface and bring the slide under control. Even a small amount of throttle (on or off) or braking can effectively reduce the tyres ability to grip.
So to answer the thread question, it is either on the footrest or moving over the clutch to prepare for declutching.
The clutch should not be dipped as a first resort.
If through the sequence of the slide (oversteer) you run out of steering lock, lifting off the throttle (even gently) can aggravate the situation and so if you dip the clutch you remove all internal influences from the wheels. As a result, you give them maximum chance to regrip the road surface and bring the slide under control. Even a small amount of throttle (on or off) or braking can effectively reduce the tyres ability to grip.
So to answer the thread question, it is either on the footrest or moving over the clutch to prepare for declutching.
13 March 2007, 10:36 PM
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When I first got my 1st Impreza, after about 2 weeks of ownership I lost it completely on a wet road. It was a left-right-left sequence of bends and going into the right it got into terminal understeer, I lifted slgihtly and the back end came round. Applying the gas didn't help to recover it and by this time I was at 90 degress to the road and running out of room. I decided I was a passenger for the duration and dipped the clutch, at which point it recovered all grip and straightened up a treat!
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