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Old 3rd February 2011, 11:18   #31
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

^Thanks for the update friends.

I meant due to hard braking and front engine car with plough and as he initiated the Scandinavian flick by steering in both the direction to prevent hit this gave rear tyre of car a reason to go airborne. ABS saved the day for him, ESP and EBD should be standard now in India as well as gen next cars are capable to do over 100 easy and road infra is not up to the standard. These are life saving equipment and sorely missed in cars less than 20L range. I agree that tyre condition and patch size does matter.

My ANHC VMT does not have a disc rear brake, shame on you Honda.
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Old 3rd February 2011, 11:53   #32
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

My personal opinion:-
I don't think one can give advice on how to brake or how to steer during such circumstances. Your instinct kicks in and you do what you have to do to try avoid such collisions. You did what you had to and escaped with no major issues.

Even practicing day in and day out to brake will not help in such situations. No one can train to react to such situations.

Only thing you can check is if the brakes and tyres are good.

Last edited by GTO : 5th February 2011 at 14:17. Reason: Correcting spellings. You need to proof-read your posts before submission
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Old 3rd February 2011, 12:09   #33
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

@phoenix-thats gruesome accident with the indica!Did you spin out of control before hitting the median?And ya as you rightly said in your previous post tyres do matter a lot.I think the stock apollo acellers are just not good at handling such situations.Who knows with a better set of rubber,this incident might not have occurred at all!

All in all i can say is it was mainly a human error which may have happened due to me panicking on seeing the man crossing and sand under the wheels.I also have decided not to cross 70(max 80) kmph at night on 4 laned roads .Even though i am running on philips Extreme power headlamps (which are way better than stock) night time you can never have the clarity of vision as in a day time.

It was due to ABS EBD combo that the speed cut down drastically even though two of the wheels were on sand and the spin that happened later was controllable.And glad that all 4 in the car were wearing seatbelt which pulled me to the seat when the car spun preventing secondary damage.Above all this it was Gods grace that saw us safely though this incident

Last edited by sagarpadaki : 3rd February 2011 at 12:14.
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Old 3rd February 2011, 12:12   #34
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

What you said is very right! Its the survival instinct that takes over in such situations.You cant teach those.
Brakes are top notch with the 4 discs ABS EBD combo.I can say i20 is one of the hatches with the best braking!

Last edited by GTO : 5th February 2011 at 14:18. Reason: Removing quoted post as it has gone through corrections
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Old 3rd February 2011, 13:03   #35
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

^ you can teach a driver and that is what the top drivers are taught at the academy.
Survival Reaction or SR is not always right till you have mastered/practiced.

A good reference to this is Twist of the Wrist II and you will know what I am saying.
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Old 4th February 2011, 00:16   #36
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by libranof1987 View Post
* I'm wondering, when you are ~ 100km/hr and barely have some distance to go before collision, shifting gears wouldn't really come to mind first right??
Also, if you were to downshift to come to halt more effectively, would the time taken for downshifting not eat into the braking time?? Or you brake and downshift simultaneously?

* Wonderful observation! Never thought on such lines. But here's a doubt. Does the ECM, rpm etc etc. come into the picture only when the clutch is depressed.
Quite often, you tend to press both the brake and clutch while emergency braking. So, with the clutch pressed, the ECM wouldn't really push the rpm right? Ergo, it wouldn't be acting against the braking.
Braking even while you are cutting the gear down - takes practice, try doing that even when slowing down normally, and you will get habituated to it - cut gears down before stopping at signals, when you reach your destination, etc. Engine braking is very very effective when you have to come to a sudden halt provided you react quick enough.
Quote:
Originally Posted by VW2010 View Post
My personal opinion:-
I don't think one can give advice on how to brake or how to steer during such circumstances. Your instinct kicks in and you do what you have to do to try avoid such collisions. You did what you had to and escaped with no major issues.

Even practicing day in and day out to brake will not help in such situations. No one can train to react to such situations.

Only thing you can check is if the brakes and tyres are good.
Completely agree - instinct is pretty much uncontrollable. But it can be influenced. Really. Am not kidding!
Quote:
Originally Posted by sagarpadaki View Post
@phoenix-thats gruesome accident with the indica!Did you spin out of control before hitting the median?And ya as you rightly said in your previous post tyres do matter a lot.I think the stock apollo acellers are just not good at handling such situations.Who knows with a better set of rubber,this incident might not have occurred at all!

All in all i can say is it was mainly a human error which may have happened due to me panicking on seeing the man crossing and sand under the wheels.I also have decided not to cross 70(max 80) kmph at night on 4 laned roads .Even though i am running on philips Extreme power headlamps (which are way better than stock) night time you can never have the clarity of vision as in a day time.

It was due to ABS EBD combo that the speed cut down drastically even though two of the wheels were on sand and the spin that happened later was controllable.And glad that all 4 in the car were wearing seatbelt which pulled me to the seat when the car spun preventing secondary damage.Above all this it was Gods grace that saw us safely though this incident
Close to 3 AM, usual route - 100 feet bypass road, and a Indica (pre Turbo) doing 100. That's when a dog decides to chase it almost coming under the wheels. All i did was a flick to the right The good hearts at Madras Traffic Police decided to throw a few boulders in the middle of the road the previous evening (seriously) for median, and my car ran over it. The rest, like they say, is history

All said and done, it is always the God above that is keeping us where we are and what we are. But then, he always leaves behind a lesson...

Last edited by GTO : 5th February 2011 at 14:19. Reason: Correcting quoted post
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Old 4th February 2011, 00:30   #37
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by supremeBaleno View Post
If I got the scenario correct, it was similar to what happened to me some years ago. Infact the similarity is uncanny - what was supposedly a slight flick of the steering results in violent uncontrollable swerving, lasting for a few seconds, finally car is perpendicular to median, but finally no damage/injury to car/driver. Only difference was I was in a Baleno and did not have ABS. Plus you tried to avoid a man, I was changing lanes to avoid a car in front.

And what you term as a "small flick" of the steering, at high speeds can result in loss of control - resulting in a series of corrections done by you to correct each swerve.

Are you sure the speed was 70-80kmph ? I would think it was higher for you to lose control and swerve so wildly - atleast in my case it was.

A thread exists for it on tbhp, but I don't want to be reminded of that day.
I recreated this on the track, remember?
It's called a tank slapper.
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Old 5th February 2011, 19:46   #38
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by sagarpadaki View Post
The right two wheels were rolling on gravel and the left two wheels on full tar road.The ABS kicked in and felt the brake pedal pulse.I severed to the left to avoid the man and that moron panicked and ran backward instead of continuing his course.This made me cut to the right again and the car lost control.
Firstly, when either side of the car has different grip levels (e.g. LHS tyres on slipper surface, RHS on grippy), that leaves the door wide open for slides.

Second, you just put the car through crazy weight transfer.....something that few everyday cars would ever handle well. When you swerved to the left, there must have been heavy weight transfer on the RHS. Presumably, before the car was fully stable, you cut to the right, which completely messed the balance of the car up. At such a point, the car is pretty much uncontrollable.

All of us face emergency situations on the road; I'm just glad that no one was seriously hurt in this incident. A certain BHPian once toppled his Getz after a similar maneuver some time back.

Last edited by GTO : 5th February 2011 at 19:49.
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Old 5th February 2011, 23:46   #39
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by GTO View Post
A certain BHPian once toppled his Getz after a similar maneuver some time back.
This is definitely what they call 'timing'! I went through something very similar to what Sagar went through - albeit I was expecting it - just a couple of hours ago. On my Getz CRDi.

Close to 90 degree turn in Besant Avenue Road (Madras BHPians would probably know - the one after Theosophical Society). Deserted road, I usually take this turning at 60 in 4th, and car handles it well enough. Today, I tried pushing it - 70 in 5th. Half way into the turn I realize the rear end falling out of line. Mild correction - bit of a brake and cut to 4th gear. I guess the brake was the mistake, the car *almost* swerved towards the median. Like I said, I was expecting this, more so after this thread, and corrected it to a straight line without anymore ado...

Herez a map of the road I'm talking about - I have circled out the turning.
Name:  Limits.png
Views: 481
Size:  13.5 KB

Moral of the story - Don't push a Getz much, it is no handler
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Old 7th February 2011, 19:18   #40
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

This thread gives me a sense of deja vu - I had highlighted this very twitchy behaviour of i20 after a test drive and got a lot of flak for starting a new thread, so much so that the Hyundai fanboys reported it and it was taken offline and then added back into the test-drive thread.

http://www.team-bhp.com/forum/test-d...ml#post1404356 (Test Drive : Hyundai i20 CRDi.)

And trust me, I was simulating exactly the same behavior(of an emergency lane change) for the i20 and it failed, not once, but twice.

Disclaimer 1:- I am not discounting that the experience of the OP poster might have been slightly different to what I did, with braking and a different surface involved on one side of the car. I think the twitchy nature of the i20 along with the corrective inputs made it fishtail, fortunately the OP was able to recover. I may be wrong with the last part, though.

Last edited by kuttapan : 7th February 2011 at 19:20.
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Old 7th February 2011, 22:13   #41
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by kuttapan View Post
This thread gives me a sense of deja vu - I had highlighted this very twitchy behaviour of i20 after a test drive and got a lot of flak for starting a new thread, so much so that the Hyundai fanboys reported it and it was taken offline and then added back into the test-drive thread.

http://www.team-bhp.com/forum/test-d...ml#post1404356 (Test Drive : Hyundai i20 CRDi.)

And trust me, I was simulating exactly the same behavior(of an emergency lane change) for the i20 and it failed, not once, but twice.

Disclaimer 1:- I am not discounting that the experience of the OP poster might have been slightly different to what I did, with braking and a different surface involved on one side of the car. I think the twitchy nature of the i20 along with the corrective inputs made it fishtail, fortunately the OP was able to recover. I may be wrong with the last part, though.

I too experienced the same thing.The difference was that you did it deliberately but in my case it was purely accidental
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Old 11th February 2011, 13:32   #42
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by GTO View Post
Firstly, when either side of the car has different grip levels (e.g. LHS tyres on slipper surface, RHS on grippy), that leaves the door wide open for slides.
Wouldn't EBD help in this case? I was under the impression that EBD was precisely for this.
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Old 13th February 2011, 13:50   #43
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by ph03n!x View Post
Half way into the turn I realize the rear end falling out of line. Mild correction - bit of a brake and cut to 4th gear. I guess the brake was the mistake, the car *almost* swerved towards the median...
May be the downshift did more damage than braking.

Having said that, why would your car oversteer? It should understeer, unless you applied brake?

Quote:
Originally Posted by ph03n!x View Post
Moral of the story - Don't push a Getz much, it is no handler
To generalize, some understanding of your car's on the limit behavior helps everyone. Some cars save you on your day of stupidity, some bite back.
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Old 13th February 2011, 23:11   #44
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

Quote:
May be the downshift did more damage than braking.
In a curve down shifting is the way to go when you feel the car beginning to go away from the intended trajectory. Braking in the middle of the curve is almost always disasterous. One should be done with all the brake inputs before one enters the curve. Once in, the Centripetal force that holds it in the curve does not like being disturbed. Downshifting is the way to go whether you need to slowdown or need to increase the speed to hold the trajectory of travel in curves that become tighter as you go further in to them.


@sagarpadaki

What happened in your case is that after the first input to the left the car's mass also followed to go left and when you fed in the second input it took time for the mass of the car to change its direction of travel from left to right. This made the car trip on itself as while the front wheels were pointing due right the car's mass was still travelling left. This made the car trip on itself and you felt that in the form of a lift of the rear tire (should have been the left rear). As you straightened up the mass had shifted due right and with the decrease in speed as the tires became stationary the mass read momentum continued to the right and that turned the car. Do let me know your final stationary position, as in facing away from the central median or towards it. Per my understanding it should be the latter.

The i20s long wheel base and the low C.O.G. saved the day for you as did the ABS and the braking components which in an ABS variant for a given car are far superior compared even to those in non ABS versions of the same model.

ESC would have helped here in avoiding this gap between the steering input and the mass(momentum) following. EBD would have helped definitely as it would have transferred more brake power to your two left wheels which were on the road and thereby had more friction/traction to work with. This would have given you a shorter straight line distance to halt than what an ABS only equipped vehicle would take.
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Old 14th February 2011, 04:13   #45
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Default Re: Emergency manouveur in my i20 diesel. Need to understand what happened

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Originally Posted by WhiteKnight View Post
May be the downshift did more damage than braking. Having said that, why would your car oversteer? It should understeer, unless you applied brake?
Quote:
Originally Posted by khoj View Post
In a curve down shifting is the way to go when you feel the car beginning to go away from the intended trajectory. Braking in the middle of the curve is almost always disasterous. One should be done with all the brake inputs before one enters the curve. Once in, the Centripetal force that holds it in the curve does not like being disturbed. Downshifting is the way to go whether you need to slowdown or need to increase the speed to hold the trajectory of travel in curves that become tighter as you go further in to them.
Like Khoj said, cutting down a gear (or two in my case) helped me reduce speeds and gain traction. It is probably the braking on the sandy banks of the road (combined with my foolishness of attempting the curve in 5th @ 70 KMPH) that set me off course - the car refusing to turn while am in the curve. And the Getz has this torque over-steer that would have kicked in when I cut gears down, making me go towards the median.

I also recently learned that the usual nitrogen pump that I fill my tires is not calibrated, and fills about 3 PSI higher - combine that with the almost worn out S.Drive (~37k KM), and its recipe for disaster!
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