abs and awd in relation to skidding

[triffid]

Thanks for clarifying, Warpspeed. I appreciate your taking this much time to do this. Hope I come across some open ground or wide track to practice. As you say the key is have mastered the technique and done it often before the emergency itself is upon you, so that the technique kicks in  almost automatically. As an aside your second method is close to Seedy's who said just turn the wheel and hit the throttle hard and steer/power out of it - you suggest waiting until the tyres grip and he says don't wait.

Anyway, thanks again.

[triffid]

j4m35, I am not offended by the suggestion that my driving was at fault. Obviously it would have helped if I was at a lower speed but I know that I wasn't going at a crazy speed. I don't recall the details nor maybe understand the term precisely enough to say whether the car oversteered or understeered. I know that i found my self going into a counterclockwise spin. I would have braked, I would have taken my foot off the throttle - maybe I did both before as well as after the loss of control - so yes maybe that caused the spin. There could easily have been a spill on the road too. You're right that I didn't have all the space in the world - just two lanes going down in a bend with barriers on either side.

 

Anyway, once the car gets back from the garage I'm going to get me an awd mazda cx5 :)

 

PS, maybe the fact that my reactions are not wha they were was a factor - I'm in the my sixties :(

[triffid]

[attachment=277780:IMG_1611.JPG][attachment=277781:IMG_1627.JPG]

[WarpSpeed]

Thanks for clarifying, Warpspeed. I appreciate your taking this much time to do this. Hope I come across some open ground or wide track to practice. As you say the key is have mastered the technique and done it often before the emergency itself is upon you, so that the technique kicks in  almost automatically. As an aside your second method is close to Seedy's who said just turn the wheel and hit the throttle hard and steer/power out of it - you suggest waiting until the tyres grip and he says don't wait.

Anyway, thanks again.

I realize that Seedys was very close to mine, I mentioned him in the earlier post and several others as well, he's not far off but the techniques I added control wheel spin and that is critical in any case but especially with FWD which has a tendency to continue to pull you in the direction of the decline or where your momentum was going from the beginning when you're sliding (besides not having, in most cases a limited slip differential or traction control) but as has been noted I have a few years and thousands of miles both on and off the track and plenty of high speed miles attempting to perfect it. Likely no one here will get to that level but it is also not necessary to be that proficient in order to possibly save yourself or someone else's life or at minimum lessen a potentially big impact.

 

In dry weather where traction loss is less likely when accelerating and turning at the same time, his advice is spot on, floor that sucka! And steer in the direction away from potential impact. Difficult to learn, as it goes against every driving instinct you have ever learned previously and frankly there really is few safe ways to practice that except maybe to take a traffic cone into a parking lot, again somewhere "safe", and try driving straight at the cone, slamming on your brakes a small distance from it and then once a slide is induced turn the wheel hard and floor it to go around safely, and try both directions to polish instincts for both directions. another important tip: Both hands on the wheel, no one handed, top of the steering wheel rubbish, with FWD, things are going to happen very quickly and violently and you have the added negative effect of torque steering on the wheel so important to have complete control and short as possible reaction time..

Just noticed your last sentence, these techniques will hep you decrease your reaction time as well that's why they work in high speed situations as well.. But you have to be very clear on your footing so you don't get confused in that moment which is why practice somewhere safe is so critical. 

 

Personally from the pics it's hard to get perspective but in what you've described as the conditions of the time etc. it seems nearly impossible you that you could over steer. The difference is when you over-steer, unless you do a complete 360 degree spin there would be no way you could nose into a wall like that, more likely you'd back into it 180 degrees, that is a very rare instance with FWD. from the marks on the wall, presuming the dark ones are your new paint and the direction of your tires it seems you hit the wall nose first and slid a few feet before coming to a stop? That seems like under-steer where you tried to turn the corner and the car continued to slide forward into the barrier, meaning the steering direction did not really change much and just traveled mostly forward not responding at all, or very little to your steering input. Most factory cars, especially FWD are set up this way intentionally as an over steer can throw the car into a violent uncontrollable spin that few daily drivers can handle so they set them up to under-steer instead for safety purposes. Controlling over-steer well is a special talent that takes even more practice then what I'm suggesting for the under-steer.

Edited August 3, 2014 by WarpSpeed

[J4M35]

Warpspeed, as you say this forum is a medium for discussion so perhaps instead of posting facepalming emoticons, condescending remarks and casting aspersions about my own driving, we can focus on the topic in hand. You will not see me making this personal by making comments about you or your own driving.

 

Firstly you have obviously misread my previous post as I at no point described a track as having ‘perfect surfaces’, only that it was a “controlled” environment “where there is smooth tarmac, hundreds of meters of run-off and no pedestrians or fellow road users”. Your suggestion that the public road is like a street circuit serves only to illustrate that you have missed my point, have you ever seen a Kebab stand on race weekend Monaco circuit, or school children waiting for the bus at Albert Park during a race? No, these venues are closed to all but racing and course vehicles, ARMCO barriers are erected, marshaling posts are installed etc.

 

By all means accelerate your way out of trouble on a circuit but on the public road doing this may have been the difference between hitting the barrier or missing the barrier and going over the edge, or taking out a bus stop full of school children, or clipping the curb and rolling the car, or hitting a drain cover or a join in the concrete which causes further loss of control. Also there is quite a difference between being able to apply these advanced skills in a controlled situation and being able to apply them instinctively when the loss of control is completely unexpected. It is unreasonable to expect anybody who doesn’t have significant experience in car control to instinctively and effectively apply these techniques.

 

I’m more than used to driving in adverse conditions being from the UK where it normally snows in the winter and we have a lot of rain. I have used these techniques to get out of trouble on UK roads but I have significant experience of a variety of cars on a variety of circuits in a variety of conditions, as well as experience of driving road cars in snow, ice, rain etc.

 

Secondly, “I was going into a downhill leftward bend and the back of the car swung to the right - of course I didn't keep my head and swung the steering wheel right round to the right“, “I know that i found my self going into a counterclockwise spin”… You suggested that my “perception of what the Op stated is not even correct”, It sounds very much as though you are the one who has misinterpreted Triffid’s description as to me this is the definition of oversteer. Oversteer in a FWD car is more than possible with abrupt steering or abrupt release of the throttle, particularly downhill, in the wet and where excessive speeds for the conditions are factored in, plus the unknown tyre pressures.    

 

Wilcopops, I was expecting somebody would bring up engine braking. My reasons for not mentioning this are twofold;

Firstly, very few 4WD systems are permanently and positively engaged and therefore able to support engine braking on all four wheels. The only way you’d achieve predictable and consistent engine braking in a 4WD car would be if it was a permanent 4wd with the center diff locked (vanishingly few vehicles do this). 

Secondly, the majority of 4WD vehicles I have seen here are automatic transmission, which means that the driver has not selected the gear and therefore is unlikely to know in the moment which gear the car is in- this means that the amount of engine braking available is often negligible, especially since ATs tend to hold onto the higher gears until the driver applies the throttle again causing it to kick down. Furthermore because there is no permanent mechanical connection between the engine and the gearbox with an AT, the amount of engine braking will inevitably be much less than with a manual vehicle.

[WarpSpeed]

Warpspeed, as you say this forum is a medium for discussion so perhaps instead of posting facepalming emoticons, condescending remarks and casting aspersions about my own driving, we can focus on the topic in hand. You will not see me making this personal by making comments about you or your own driving.

 

 

To avoid that response don't contradict me with a condescending tone to your post, and think out a bit more before posting it, simple really.. I'm not going to rebut your entire post because there is too much to do so, because backtracking and side stepping posts such as below make it tedious to do so, and besides even this post is nonsense it is not a "controlled" environment quite the opposite and as you mentioned in your previous post it is not true that there are not "other" vehicles and distractions to contend with but I went easy on that remark, so put your pride back in your pocket let the hair on your neck settle and take a few lessons.. No fellow road users? at 100 to 150 MPH and more? Again that kind of comment is what rightfully garners this emoticon ..

 

 

I at no point described a track as having ‘perfect surfaces’, only that it was a “controlled” environment “where there is smooth tarmac,

The head slap was because you failed to read the posts, made comments that were irrelevant and lecturing in a tone regarding my giving him professional advice on controlling his car when your post was incorrect from the first sentence describing over-steer instead of what is actually under-steer. You did the same and got it back in response the only difference is I used emoticons to display the silliness of your post instead of the tone you used to incorrectly contradict mine.

Edited August 4, 2014 by WarpSpeed

[J4M35]

As I said, this is a discussion forum- I can contradict you if I wish, that's how a discussion works. It's quite funny that you're not going to rebut my entire post because it's too much work, I though we were trying to help a fellow contributor?

 

Having said that it is quite apparent that you don't have the time to rebut my post because it doesn't appear you had time to read it either. If you had, you would have seen that in the fifth paragraph I quoted pertinent sentences from the OP to show that the car oversteered and that your assertion that it was in fact understeer goes against the description of the only person who was actually there, the OP.

 

Please, if you find anything actually objectionable about my posts other than the fact they contradict yours, let me know, and I'll be happy to justify them without resorting to calling anybody 'silly', nor a 'numpty'

[triffid]

Gentlemen, please! The last thing I want is to provoke an altercation. Frankly my memory at the best of times is less than perfect and in recalling those panicky circumstances it is further compromised. So let's bring this thread to a close with my thanks to all contributors. 

[wilcopops]

 

Firstly any vehicle i  4WD will skid at a different point and in a different way from a 2WD.

Although many 4WD pickups in Thailand are AT there is a vast number of MT models. I've never owned an auto....driven a few but never owned.

the Pajero and Fortuner do have permanent AWD option.

In a skid it ALL WHEELS are locked then it really doesn't matter but in most skids there is a lot more going on. The vehicles don't just go into free wheel - they almost all have ABS and the driver may well apply power at some point which may be transmitted to the road or a spinning wheel. Also the front wheels are still connected to the transfer box even though they have no locking diff. (actually mine does). Virtually EVERY 4WD pick up you by will also have a limited slip rear diff. Anyone who has driven a vehicle with this in mud etc will notice the difference.

Most people involved in a skid act instinctively, which is usually inappropriately.

It takes a lot of "practice" on various road surfaces and conditions to build up a good response too a skid.

 

most 4WDs under 10 years old in Thailand are fitted with ABS, more are now fitted with ESP.

Cars like the new Subaru have wonderful 4Wd systems that make them far less likely to loose grip on any surface.

 

Here's an Aussie take on rear-end skids in 4WD....

 

So how do you recover from a rear-end skid?  All at the same time:

1. Look where you want the car to go, and look well ahead.
2. As the back end steps out, turn the steering wheel to keep the wheels pointed where you want to go.Do this quickly and positively, don't assume the car will correct.
3. Maintain the gear you’re in.
4. Slightly reduce, or maintain throttle.  This leaves as much of the tyre’s grip as possible for lateral grip as you aren’t using any grip for accelerating for braking.  A slight reduction slows the car down, and less speed is good in skid recovery. But not a quick deceleration which destabilises the vehicle.  While a weight shift to the rear under acceleration is unlikely with a heavy 4WD at speed, the brakes are powerful and you can unweight the rear end sufficiently to exaggerate a skid.
5. So now you've corrected with the steering wheel, and if you’re lucky and quick the rotation will stop.  Get ready for the next part.
6. The car’s back-end will then swing back in line.  This is where you need to be very, very quick with the counter-steer and accurately return the steering wheel to centre, or sometimes a bit beyond.  Again, don’t accelerate or brake.

[Rimmer]

Off topic baiting post removed

[seedy]

WarpSpeed - I have always enjoyed reading your posts.

 

Learn something from each and every one.

[EvilDrSomkid]

Can't be bother to writ a long post, but AWD is always better in slippery conditions.

http://www.youtube.com/watch?v=mXMVaB-wfWc

[wilcopops]

 

Regardless of which/how many wheels are driving the vehicle, running gear/suspension is a major contributor to your staying on there road.  

 

I think it's worth mentioning again that TIRES are an important part in this.......a long-lasting hard compound is not necessarily the best solution for traction.

 

You should also look at things like shock absorbers....if they are not working properly they can affect the ability of the car to keep its wheels firmly on the road.

Wheel balancing and steering geometry are also important to keeping the car on the road.

 

...and brakes------brakes that pull to the right or left are dangerous........find a suitable place (off the roads - Airfield/empty car park) to try your brakes - take you hands of the wheel and firmly apply the brakes, does the car veer to the left or right? Try this a few times to get an accurate picture.

[EvilDrSomkid]

 

 

Regardless of which/how many wheels are driving the vehicle, running gear/suspension is a major contributor to your staying on there road.  

 

I think it's worth mentioning again that TIRES are an important part in this.......a long-lasting hard compound is not necessarily the best solution for traction.

 

You should also look at things like shock absorbers....if they are not working properly they can affect the ability of the car to keep its wheels firmly on the road.

Wheel balancing and steering geometry are also important to keeping the car on the road.

 

...and brakes------brakes that pull to the right or left are dangerous........find a suitable place (off the roads - Airfield/empty car park) to try your brakes - take you hands of the wheel and firmly apply the brakes, does the car veer to the left or right? Try this a few times to get an accurate picture.

 

 

Yes, it is amazing how many times people forget the basics. Agree with everything you say.

 

Its amazing to see how many people drive here with clapped out shocks and bald tires.
 

[Kwasaki]

 " amazing to see how many people drive here with clapped out shocks and bald tires."  Not really see it every day. 
 
 

 

This thread reminded me of what Clint Eastwood once said  " You have to know your limitations."

Edited August 8, 2014 by Kwasaki

[bkkjames]

The nicest thing about being the least knowledgeable person in the motoring forum is never having to defend my position lol