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Old 12th April 2008, 21:16   #1
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Default What to do when your car aquaplanes

Was going down a circular parking ramp. 20~30kmph. usually am alone , but had 3 others with me today. usually I'm able to keep in control, but towards the end of one of the level sections , went into oversteer and lost control totally. thankfully since i was going at a low speed, stopped soon enough, coming to rest perpedicular to the direction i was traveling. But even that momentary loss of total control was quite unsettling.

Have had a few instances where I've lost traction at the rear when cornering for a fraction of a second. Think the extra load due to the people at the rear might have made it worse.

What is the correct way to recover from such a situation ?

Last edited by greenhorn : 12th April 2008 at 21:18.
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Old 12th April 2008, 21:28   #2
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Oversteering at such low speeds?? Are your tyres in good condition? And what do you 'Aquaplaning'? Was their water present on the ramp?
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Old 12th April 2008, 21:32   #3
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yup, had rained all night. and there was a downward slope and the surface was concrete tiles with some patterning.

what i meant was that the rear end swung out despite me braking when coming down, like it was tail heavy. That is oversteer right ?

Tyres have run 10,000k. Just got them rotated at second service. Bridgestone S322. the ones that come stock with the indica

Last edited by greenhorn : 12th April 2008 at 21:35.
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Old 12th April 2008, 21:36   #4
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greenhorn, was this in Trivandrum? If so, where? Might be useful for others like me And what do you mean by aquaplaning?
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Old 12th April 2008, 21:42   #5
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our office has two of the basement floors left for parking. this happened when i was going down the circular ramp which leads to the basement floors. They've put a "dead slow" board there , but

I believe aquaplaning is when your car loses grip totally when on a waterlogged surface

EDIT: googled for it- the wikipedia link looks helpful

Any advice from you guys (other than to avoid it in the first place)

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Old 12th April 2008, 22:29   #6
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not much you can do in aqua planing. pray, sit tight, and hope the vehicle stops before its stopped by the scenery.

the following points are not in any specific order of priority, just what I could come up with off the top of my head.
its not rocket science

1. try to avoid braking during a turn
2. brake earlier in the rains
3. brake gradually
4. no sudden, wrenching movements at the steering wheel
5. keep tyres at proper inflation
6. make sure the tread is deep enough.
7. unidirectional treads are better in preventing aquaplaning(experts please verify)
8. stay away from puddles
9.keep hold of the steering wheel, do not wrestle with it, when the traction comes back the steering will weight up and you may be able to gently steer away or pick a soft spot to crash.

also, losing traction in 4 wheels is worse than losing traction in 2 wheels.

if the car is over or understeering due to traction loss in either rear or front tyres respectively, treat the situation just like any over/understeer situation

Its all very well to discuss these things over a keyboard, but when it happens, its usually the first sentence i typed.

best is to?.......take a wild guess!!!!

yes,thats it-Slow down!
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Old 12th April 2008, 22:40   #7
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From what u say i believe the surface was only wet not water logged...

AFAIK aquaplaning occurs when u hit the water puddle at much higher speed than 20kmph...
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Old 12th April 2008, 22:43   #8
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it was waterlogged. water had pooled there.

@ rippergeo- thanks

is there anything we should NOT do ?
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Old 12th April 2008, 22:50   #9
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You must be sliding, not aquaplaning. Aquaplaning happens when there is a 'relatively' thick layer of water between the tyre and the surface below. I have experienced it in straight line conditions, one looses steering authority... Avoid going too fast through wet patches is all I can say. Tyres can help somewhat.
You may have slipped due to there being a thin film of oil on the water, a deadly combination.
Dont give ANY sudden inputs to the brakes and the throttle (that includes lift-off) during oversteer.

@EDIT, oh, was it waterlogged?

Last edited by Alfa_Kilo : 12th April 2008 at 22:51.
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Old 12th April 2008, 23:02   #10
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Quote:
Originally Posted by greenhorn View Post
it was waterlogged. water had pooled there.

@ rippergeo- thanks

is there anything we should NOT do ?
obviously- avoid the situation(I never tire of saying that)
but if it occurs,

try NOT to use the brakes, use only if its a dire emergency.
if you have ABS, it may save you. if not, the next best thing is to pump the brakes.

ease off the throttle(NOT lift off)

Do NOT wrestle with the steering. see sawing the steering will only prolong the slide.
when the traction returns to the front wheels you will feel it. then you may try to GENTLY steer away.

I'll say this again
this is all theory, whether you come out of such a situation or not, is mostly luck for drivers with our skill level.

I've been lucky thrice- not keen on testing my luck again.

all 3 times, i realised what was happening right away, had the presence of mind to avoid doing the above actions.
(but not the sense to slow down when it rains)

No matter what some people say, it helps to be prepared.
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Old 12th April 2008, 23:09   #11
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Take your foot off accelerator pedal. Reduce speed. Shift to lower gear.
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What to do when your car aquaplanes
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Old 12th April 2008, 23:26   #12
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umm, i recall reading from a swift vxi's case that its better to steer INTo the direction of the skid to come out of it, or such. is that correct?
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Old 13th April 2008, 01:44   #13
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Greenhorn,

In your situation i'm unsure of whether your car was aquaplaning, or the tyres just had reduced traction due to the wet surface (which in theory is aquaplaning on a smaller scale - but i would wouldnt be classified as "aquaplaning").

As everyone here has said, prevention is better than cure. The two most important factors in preventing aquaplaning are :
1. Good tread depth should be left on your tyres
2. Drive at a slower speed.

Here is an interesting video as well : http://www.team-bhp.com/forum/modify...tml#post766056 (ARTICLE: Choosing The Right Set Of Tyres for your Car)


From your explanation is seems like you were cornering fairly hard with an increased load in the back of the car.
Chances are that your tyres were already fairly wet, and close to breaking lateral traction (and as per newtons 1st law, the extra mass in the back would make the car (especially the rear of the car) want to continue to go in a straight line, as opposed to turn). - Also the explaination for why the earlier rear-engined 911s were so hard to control.
When you hit the patch of standing water, it probably further reduced the traction the tyres were capable of, and hence the car spun.

I believe there is a video in one of the bangalore meet threads where a zen is going up a mountain road, around a corner, and then hits a patch of standing water and spins out. Can anyone find the thread/video?

So to get to your question of what you can do :
1. Don't lock the brakes. Let the wheels rotate freely, they will probably regain traction better this way (correct me if i am wrong), after which you can begin to brake (keeping within traction limits)
2. Remember that the car is likely to keep going the direction it is sliding in (regardless of if it is going sideways/backwards or spinning around) - so if you think that is the safest direction to keep going, dont try and change it.
3. Turning into/towards the direction of the skid would make sense in order to regain control faster, however, this definitely opens up the possibility of fishtailing, which is incredibly difficult to recover from.

As has been said before, there really is no proven recovery solution for aquaplaning.

Quote:
Originally Posted by rippergeo View Post
7. unidirectional treads are better in preventing aquaplaning
In theory, a design change made specifically for an advantage in a certain area should yeild better results in that area. However, proof is in the pudding. Im sure there are some unidirectional tyres which perform worse in the wet that some non-directional tyres.

Quote:
Originally Posted by phamilyman View Post
umm, i recall reading from a swift vxi's case that its better to steer INTo the direction of the skid to come out of it, or such. is that correct?
As mentioned above, that makes sense - moreso in the dry. This is basically "opposite lock".

cya
R

Last edited by Rehaan : 13th April 2008 at 01:47.
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Old 13th April 2008, 12:51   #14
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Quote:
Originally Posted by Rehaan View Post
I believe there is a video in one of the bangalore meet threads where a zen is going up a mountain road, around a corner, and then hits a patch of standing water and spins out. Can anyone find the thread/video?
Rehaan
Even i searched for the same video but the rapidshare link now says "File deleted".
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Old 13th April 2008, 13:52   #15
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Quote:
Originally Posted by greenhorn View Post
Was going down a circular parking ramp. 20~30kmph. usually am alone , but had 3 others with me today. usually I'm able to keep in control, but towards the end of one of the level sections , went into oversteer and lost control totally. thankfully since i was going at a low speed, stopped soon enough, coming to rest perpedicular to the direction i was traveling. But even that momentary loss of total control was quite unsettling.

Have had a few instances where I've lost traction at the rear when cornering for a fraction of a second. Think the extra load due to the people at the rear might have made it worse.
Quote:
Originally Posted by greenhorn View Post
yup, had rained all night. and there was a downward slope and the surface was concrete tiles with some patterning.

what i meant was that the rear end swung out despite me braking when coming down, like it was tail heavy. That is oversteer right ?

Tyres have run 10,000k. Just got them rotated at second service. Bridgestone S322. the ones that come stock with the indica
Dude, oversteer happens when the car gets nose heavy and not tail heavy (one exception which I have spoken about later). As a result, rear tires end up with less traction than the front- and the tail steps out the moment the inertia is enough to break it lose. If you have people in the back of the car in a front-engined vehicle (irrespective of the fact whether its a FWD or RWD), in low traction situations it will offer better stability due to better front-rear weight distribution and aid handling- and not the other way round.

Now, in your case, you were coming down a slope with less than adequate traction. When the car is on a decline- without any weight transfer- the car is already in a nose-heavy position. (See the top sketch)

Now while coming down the slope, you use the brakes, even though very gently, slowly more weight is being shifted to the front of the car. Now the moment weight transfer gets nose-biased to such an extent that rear tyres don't have enough weight over them (less traction) to let them grip sufficiently, (see second sketch) they break loose. It isn't strictly aquaplaning as Rehaan said, but the water does act as a catalyst which means that the rear end has much less traction to play with, than it would have in a similar condition sans the water element.

Coming to the exception in regards to weight distribution,
a rear engined car (Porsche for example) will go into an oversteer because of being tail heavy and not nose heavy as in the cases of front engined cars. The tail will break sooner because of the added inertia of the engine's weight. This is same reason why earlier Porsches were notoriously difficult to handle, understeering into a corner because of lack of front grip (no weight over the front axle) oversteering at the exit while getting on power because of the heavy tail's inertia.

P.S. Excuse the smudgy sketch, it was the best I could manage in MS Paint.
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