Would you apply you handbrake in a skid

Would you apply you handbrake in a skid

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Discussion

bmw114

Original Poster:

676 posts

237 months

Sunday 23rd October 2005
quotequote all
This is purely hypothetical because believe it or not it has`nt happened to me.
If you had a powerful car with rear wheel drive and you were going straight on at a roundabout and you were giving it some stick.

You steer left as you enter the roundabout, shifting the weight to the right , then you turn right shifting the weight to the left, then you turn left to leave the roundabout again shifting the weight to the right.
Again hypothetical you are hard on the gas almost braking traction due to the hard accelaration and then you hit lets say black ice or diesel.
The back end goes out,you steer into the skid and of course get off the gas, would your back wheels still be spinning due to the ice(diesel)thus not helping you to correct the skid.

So my question is.

Would it help your situation if you pulled your hand brake on for a split second just to stop the wheels from spinning.

StressedDave

839 posts

262 months

Sunday 23rd October 2005
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In the circumstances described, what is stopping you from using the main brakes to do the same thing? A little dab of the brakes would have the same effect on all four wheels which would not necessarily be a bad thing as the skid might have been caused as much by too much front grip as the absence of rear grip. They also tend to be a little more powerful so you'll get the slowing down without the risk of rear wheel only lockup.

That said, it's not unknown to use the handbrake to act as a sort of limited slip differential by prevent one wheel from spinning up under the application of power.

cptsideways

13,545 posts

252 months

Sunday 23rd October 2005
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In the drift world there is a defined technique & I'll explain it, however on the road I doubt anyone would find themselves in a situation to use it, especially without practice. I would however suggest if your exiting the roundabout backwards with the brakes full on & the front wheels locked you pull it on as the rear brakes by themselves do just about bugger all at this moment in time.

Drift Technique Explanation: Having drifted into & through a corner with excessive sliding & wheelspin & hence lots of tyre heat (the tread will be melting) as you exit the corner its often quite difficult to get traction to accelerate up the road (read circuit), using an effective hydraulic handbrake, brief tugs whilst still under power is often just enough to regain that extra bit of traction required. Your effectively slowing the wheels down that little bit.

Using this technique there is a definate sensation of acceleration & traction as you shoot forward that little bit & is a most strange effect from tugging the handbrake. We use it in drifting to gain speed & when twin drifting side by side to match the other cars speed.

>> Edited by cptsideways on Sunday 23 October 22:19

GreenV8S

30,191 posts

284 months

Sunday 23rd October 2005
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There is a similar technique which can be used in very slippery conditions. If you pull on the handbrake it increases the friction within the diff and this enables an open diff to behave a little bit like a limited slip diff.

woodytvr

622 posts

246 months

Monday 24th October 2005
quotequote all
bmw114 said:
This is purely hypothetical because believe it or not it has`nt happened to me.
If you had a powerful car with rear wheel drive and you were going straight on at a roundabout and you were giving it some stick.

You steer left as you enter the roundabout, shifting the weight to the right , then you turn right shifting the weight to the left, then you turn left to leave the roundabout again shifting the weight to the right.
Again hypothetical you are hard on the gas almost braking traction due to the hard accelaration and then you hit lets say black ice or diesel.
The back end goes out,you steer into the skid and of course get off the gas, would your back wheels still be spinning due to the ice(diesel)thus not helping you to correct the skid.

So my question is.

Would it help your situation if you pulled your hand brake on for a split second just to stop the wheels from spinning.



If you are going fast enough to lose traction on the Diesel and you 'got off the gas' you'd spin. Likewise if the momentum of the car was such that it was stepping out, pulling the handbrake would also spin you.

You'd ideally need to turn into the skid and drive through it, you may come off the power slightly but not 'off it'. Space and other already spun objects might prohibit this though. So if you're going to drive fast through an island make sure your exit is clear enough for you to stop should you lose traction or be able to power through.

I don't think this will effect you anyway as you'll have DSC on your 114. If you go so fast that the DSC can't sort it out then apart from being an idiot you probably will crash as traditional techniques go out of the window when you have electronics cutting in all over the place.

I had a play with my 330D Sport Touring in the snow to see what would happen when you push it too far and it basically left you no options and more often than not had the front wheel(s) locked. In a real situation this would either push you to the wrong side of the road or into the curb - Not a problem on a wide open space.

DSC really is 'the hand of god' and a brilliant system but like I said if you're an idiot you can go beyond it and it'll be in the way.

CPT's technique (well my understanding of it) is for use once the car is back in a straight line and you're just trying to gain traction.

His second use of it is slighty different in that he is using the handbrake to keep the rear stepped out at a slower speed - To the speed of the car he his drifting next to.

Green V8's technique is very useful in the snow and has got my up some tricky hills with an open diff when the weather has been bad.

gdaybruce

754 posts

225 months

Monday 24th October 2005
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In the circumstances as described, I would think the last thing you're going to have time for is to reach for the handbrake whilst simultaneously trying to steer into the slide. If you've found some ice or diesel and you were already pushing hard, chances are you've lost it. However, I would hit the clutch and take away any engine effect - either power or engine braking will unsettle the car's balance. With the clutch disengaged, you can focus on trying to steer your way out of the accident!

Incidentally, I once did hit some diesel when pushing on at the exit to a roundabout. I was in, of all things, a Discovery which, of course, has permament 4 wheel drive. The whole car slipped a couple of feet away from the cornerning line, leaving me wondering what exactly had happened. I then glanced in the mirror in time to see a following BMW 3 series completing a balletic 720 degree spin. Gave me new respect for the Disco. It might not be sporty but 4wd and anti roll suspension makes the handling surprisingly safe.

Flat in Fifth

44,061 posts

251 months

Sunday 30th October 2005
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gdaybruce said:
However, I would hit the clutch and take away any engine effect - either power or engine braking will unsettle the car's balance. With the clutch disengaged, you can focus on trying to steer your way out of the accident!



First thing our skid pan instructor teaches. CLUTCH!

sevener

36 posts

277 months

Monday 31st October 2005
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When I was going through the training course to use a skid car for training, I had to learn this de-clutching business as the first stage in the process - the reason behind it, not as quoted but because the 'average'driver (and I use the expression advisedly and not aimed at anyone here) cannot recognise the point at which the engine will die during the whole scary scenario of a loss-of-control ... so it's better to sacrifice some engine braking for the benefit of still having a live engine at the end of the 'brown trouser' moment.

RobM77

35,349 posts

234 months

Monday 7th November 2005
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Of course if you're about to spin a RWD car a sharp jab on brake and accelerator will sort you out! (providing you don't have ABS).

bor

4,702 posts

255 months

Monday 7th November 2005
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Could you explain that in a bit more detail please, Rob ?

Thanks.

GreenV8S

30,191 posts

284 months

Monday 7th November 2005
quotequote all
RobM77 said:
Of course if you're about to spin a RWD car a sharp jab on brake and accelerator will sort you out! (providing you don't have ABS).


Equally, a sharp jab on brake and accelerator will get you in an awfull lot of trouble unless you've got the hang of left foot braking!

RobM77

35,349 posts

234 months

Monday 7th November 2005
quotequote all
bor said:
Could you explain that in a bit more detail please, Rob ?
Thanks.


Sure - it is just left foot brake spin avoidance. Basically, you brake and accelerate at the same time. The front wheels will lock up but the rears won't because you're accelerating, which stops the brakes taking full effect on the rear. The effect is a very dramatic front end wash-out in the middle of a terminal oversteer situation. I would only use this if things have gone bonkers and you're sure you're going to spin. If you've never tried this on track and you're about to spin on the public road, then I wouldn't reccomend trying it for the first time on a road! I would probably just let the car spin and hold the brakes down to ensure you come to a complete halt.

If you've ever got a FWD car stupidly sideways and floored it to recover the situation, then it is a similar feeling to that. You sort of get 'rescued' from what feels like an impossibly terminal angle of oversteer.

bor

4,702 posts

255 months

Monday 7th November 2005
quotequote all
Thanks, Rob.

I'll try it when the snow comes.

RobM77

35,349 posts

234 months

Monday 7th November 2005
quotequote all
No problem. You'll need no ABS (and of course RWD) for it to work. You'll probably also need a gentle touch in the snow, and the speed will be very low, so a slight mistake and you'll stop the rear wheels and stall the car (not an issue on track cause you're going so fast, and as long as you prevent a spin, the rear wheels will always keep up enough speed to stop the car stalling).