Discussion
Had an opportunity to have a play on some wet tarmac today, great great fun 
One thing I found really challenging was one particular corner I was drifting round had differing grip levels in differnet places (it was the double right at the bottom of the runway Bruntingthorpe FYI).
First time round:- provoke drift, get car into settled attitude asap.... hit slippery patch then - wow - where's the grip gone? result: spin
Second time:- same
Third time:- provoke drift earlier, get settled earlier, remove throttle in anticipation of the 'slippery zone' and glide across that with a little extra lock to maintain my line, when the grip comes back apply throttle hard to combat the recovery and then settle down again - recover drift in normal fashion.
So, I found the only way to manage the slippery section was to anticipate the grip level and remove the input which was inducing the spin (but had maintained the drift in the first place), namely the throttle. What I'd like to know is this:
Without the advance removal of throttle, how could I have prevented a spin? i.e, when I'm halfway round the corner and detect a drop in grip levels what inputs could have prevented a spin.... brake? shift down a gear? left foot brake? come off of everything and wait? (I know more throttle doesn't work, as that the method I use to exit the spin asap
). Basically what kind of reactive techniques can help car control in this scenario?
FWIW I was driving a non-LSD equipped Z4 Coupe
One thing I found really challenging was one particular corner I was drifting round had differing grip levels in differnet places (it was the double right at the bottom of the runway Bruntingthorpe FYI).First time round:- provoke drift, get car into settled attitude asap.... hit slippery patch then - wow - where's the grip gone? result: spin
Second time:- same
Third time:- provoke drift earlier, get settled earlier, remove throttle in anticipation of the 'slippery zone' and glide across that with a little extra lock to maintain my line, when the grip comes back apply throttle hard to combat the recovery and then settle down again - recover drift in normal fashion.
So, I found the only way to manage the slippery section was to anticipate the grip level and remove the input which was inducing the spin (but had maintained the drift in the first place), namely the throttle. What I'd like to know is this:
Without the advance removal of throttle, how could I have prevented a spin? i.e, when I'm halfway round the corner and detect a drop in grip levels what inputs could have prevented a spin.... brake? shift down a gear? left foot brake? come off of everything and wait? (I know more throttle doesn't work, as that the method I use to exit the spin asap
). Basically what kind of reactive techniques can help car control in this scenario?FWIW I was driving a non-LSD equipped Z4 Coupe
trackdemon said:
Basically what kind of reactive techniques can help car control in this scenario?
From the sound of it, you were doing roughly the right thing but too late. Recognising the signs and feel of a developing slide comes with practice, and the reaction should be instinctive.GreenV8S said:
trackdemon said:
Basically what kind of reactive techniques can help car control in this scenario?
From the sound of it, you were doing roughly the right thing but too late. Recognising the signs and feel of a developing slide comes with practice, and the reaction should be instinctive.I guess really, I'm searching for a drifters inner secrets!
Edited by trackdemon on Monday 20th August 00:17
R_U_LOCAL said:
An excellent post Reg, however it doesn't quite answer my question I don’t think there is an easy answer here.
On the road, variations of grip levels do occur. It makes sense that your overall speeds take this into consideration in the first place, particularly at junctions and exits, roundabouts etc in slippery conditions. Ditto for circuits where in the wet, there may well be more grip off line.
But you’re talking about consistent levels of grip for drifting, aren’t you?
For RWD, having steered into the slide to the max, I think it is possible to dip the clutch and remove any for/aft rotational forces from the rear wheels at all, which may allow them to pick up some lateral adhesion. But that’s pretty much a last gasp.
On closed circuits it’s all about anticipation isn’t it? There’s no special technique involved in getting you out the mire if you’ve dropped it. Just pray you have enough room, and the tarmac goes in the same direction as you for a bit longer. . .
On the road, variations of grip levels do occur. It makes sense that your overall speeds take this into consideration in the first place, particularly at junctions and exits, roundabouts etc in slippery conditions. Ditto for circuits where in the wet, there may well be more grip off line.
But you’re talking about consistent levels of grip for drifting, aren’t you?
For RWD, having steered into the slide to the max, I think it is possible to dip the clutch and remove any for/aft rotational forces from the rear wheels at all, which may allow them to pick up some lateral adhesion. But that’s pretty much a last gasp.
On closed circuits it’s all about anticipation isn’t it? There’s no special technique involved in getting you out the mire if you’ve dropped it. Just pray you have enough room, and the tarmac goes in the same direction as you for a bit longer. . .
In theory the maximum possible correction includes a small amount of acceleration, where small means relative to the amount of grip available. In dry grippy conditions this could be a moderate amount of throttle. On ice it may be so small that you can't realistically apply it without simply spinning the wheels. Just that small bit of throttle can make a substantial difference to the balance of the car and be the difference between a long slide followed by 'phew' or a slightly longer slide followed by 'oh sh!t'. The idea is to get the car onto the understeer 'hump', but the less grip there is the smaller the hump is.
Even with all the steering and throttle corrections maxed out there's no guaranty that it is catchable. Several of the effects working against you are cumulative. The grip of a sliding tyre falls off when the slip exceeds the optimum. The wheel speed will flare up as the grip drops off and take some time for your throttle control to bring it back down again. The car will keep accelerating in yaw until you have applied the throttle correction for long enough to bring the revs back down. Even after you've applied the correction and stopped making it worse, the yaw inertia of the car will mean it needs a substantially greater correction to bring the yaw rate down to zero and start bring it back into line. The further the back steps out the less control authority you have and you can very easily get to the point where it's uncatchable. A fraction of a second difference in reaction time right at the start of the slide can make the difference between just barely hanging on to it, and a no-hoper.
Even with all the steering and throttle corrections maxed out there's no guaranty that it is catchable. Several of the effects working against you are cumulative. The grip of a sliding tyre falls off when the slip exceeds the optimum. The wheel speed will flare up as the grip drops off and take some time for your throttle control to bring it back down again. The car will keep accelerating in yaw until you have applied the throttle correction for long enough to bring the revs back down. Even after you've applied the correction and stopped making it worse, the yaw inertia of the car will mean it needs a substantially greater correction to bring the yaw rate down to zero and start bring it back into line. The further the back steps out the less control authority you have and you can very easily get to the point where it's uncatchable. A fraction of a second difference in reaction time right at the start of the slide can make the difference between just barely hanging on to it, and a no-hoper.
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