Coping with understeer predicamen
Discussion
I was just curious about how people handle understeer situations when it happens or how you prevent it? This morning I was in the M3 driving on a wet slippy surface went into a slow corner and understeered just after the apex. I didn't do anything and was fine. The rear tires were pretty well loaded up too because when I put on the throttle near the end of the corner they loosened a little. Now I have see some F1 drivers like Alonso actually do sort of an opposite lock maneuver (if I'm correct) where he will unload the tires and reload them with steering angle in an attempt to gain grip. So I guess my question is what is the most efficient tactic to use? More throttle --> four wheel drift same throttle with or without steering correction (Alonso style) or lift throttle slightly for engine braking to turn the car.
Had I run out of room would applying the brakes been the correct action?
Had I run out of room would applying the brakes been the correct action?
Understeer tends to be more pronounced in tight corners under very slippery conditions. If you're supremely confident about your ability to catch and control oversteer, there are various ways you can overcome the understeer and convert it to oversteer or a neutral drift. However, the safe option is to resist the temptation to keep winding on lock, ease off the power, and wait for the speed to come down and the front tyres to grip again. If you are going to run out of road then braking will bring the speed down sharply without fundamentally changing the balance of the car, and when you come off the brakes you should be going slow enough to get round the corner without the fronts breaking away again.
The other options all require a certain amount of commitment and have a risk of a major oversteer moment ending with a backwards introduction to the scenery. Accelerating gently when the car is understeering will make the understeer worse. But if you accelerate hard, and if the engine can produce enough torque in that gear under those conditions compared to trhe available grip, you can 'drive through' the understeer hump and return to a neutral balance and then oversteer. This takes a lot of guts because things get worse before they get better, won't work if you don't have enough torque for the conditions, and will normally lead to a big oversteer moment until you balance the throttle. This is the fast but dangerous aproach. Your second option is to violently chop the throttle and then anruptly get back on the power. This will transfer weight to the front and apply a sudden torque to the back which will destabilize the car and overcome the understeer. Again it is easy to be too successfully and provoke so much oversteer that you can't catch it. Your third option is to straghten the car up and then turn in very positively again. This essentially uses the yaw inertia of the car to prevent it settling in the low slip understeer attitude and get it turned in properly. You can combine all these options for a more dramatic effect but best save it until you have an audience and plenty of run-off.
>> Edited by GreenV8s on Monday 31st January 21:53
The other options all require a certain amount of commitment and have a risk of a major oversteer moment ending with a backwards introduction to the scenery. Accelerating gently when the car is understeering will make the understeer worse. But if you accelerate hard, and if the engine can produce enough torque in that gear under those conditions compared to trhe available grip, you can 'drive through' the understeer hump and return to a neutral balance and then oversteer. This takes a lot of guts because things get worse before they get better, won't work if you don't have enough torque for the conditions, and will normally lead to a big oversteer moment until you balance the throttle. This is the fast but dangerous aproach. Your second option is to violently chop the throttle and then anruptly get back on the power. This will transfer weight to the front and apply a sudden torque to the back which will destabilize the car and overcome the understeer. Again it is easy to be too successfully and provoke so much oversteer that you can't catch it. Your third option is to straghten the car up and then turn in very positively again. This essentially uses the yaw inertia of the car to prevent it settling in the low slip understeer attitude and get it turned in properly. You can combine all these options for a more dramatic effect but best save it until you have an audience and plenty of run-off.
>> Edited by GreenV8s on Monday 31st January 21:53
a cheeky bit of left foot trail braking will also help transfer the weight onto the front of the car whilst maintaining the drive. or you can give the brakes a quick jab, but this may well have the front end shooting towards the apex of the corner as the front wheels regain their grip (through the sudden weight transfer), with the rear then going light and coming round on you.
I think the phrase 'fast hands' comes to mind. Go out on a really wet track and practice different approaches at relatively slow speeds (when there's no one directly behind you in case you spin) and see which technique feels most natural to you or where you feel in most control.
I think the phrase 'fast hands' comes to mind. Go out on a really wet track and practice different approaches at relatively slow speeds (when there's no one directly behind you in case you spin) and see which technique feels most natural to you or where you feel in most control.
The comments are greatly appreciated. GreenV8 it was valuable to hear your comments about torque necessary to turn the car because I've been in snow situations (anyway, where everything is very slow and safe) where I have added throttle and I just got more understeer but a sharper throttle response, now, makes sense to have turned the car more.
Is there any explanation for times when on turn in the car understeers? Is this a situation where you should know you have over cooked it? Or to go faster would be to come in slower and be faster at apex and thus overall faster through corner and in a better position?
I appreciate these comments because they are, now that I think about it, things I have experienced but not defined or thought about. Chopping the throttle and then reapplying does seem to arouse the rear end. I'm still wondering too, it seems like I have seen F1 drivers get front end "tank slappers" rather than just oversteer incidents.
I don't know why but understeer always seems to arouse me more than oversteer. Perhaps that is because I drive a car that rarely oversteers noticeably. I would like a little less of the former maybe a check of the tire pressures would do, not that I do this stuff daily.
Oh and in terms of trail braking. . . this technique would mean slowing the front whilst over powering the rears? (brake and throttle) Is that correct? I can see how this would make the car turn more but I fear I might just "push" the car further and it comes back to how much torque is on tap brake (break) the rear loose. correct me if I'm not understanding properly. Or do you mean a more gradual transfer at circa apex from braking to throttle?
>> Edited by pib on Tuesday 1st February 04:13
Is there any explanation for times when on turn in the car understeers? Is this a situation where you should know you have over cooked it? Or to go faster would be to come in slower and be faster at apex and thus overall faster through corner and in a better position?
I appreciate these comments because they are, now that I think about it, things I have experienced but not defined or thought about. Chopping the throttle and then reapplying does seem to arouse the rear end. I'm still wondering too, it seems like I have seen F1 drivers get front end "tank slappers" rather than just oversteer incidents.
I don't know why but understeer always seems to arouse me more than oversteer. Perhaps that is because I drive a car that rarely oversteers noticeably. I would like a little less of the former maybe a check of the tire pressures would do, not that I do this stuff daily.
Oh and in terms of trail braking. . . this technique would mean slowing the front whilst over powering the rears? (brake and throttle) Is that correct? I can see how this would make the car turn more but I fear I might just "push" the car further and it comes back to how much torque is on tap brake (break) the rear loose. correct me if I'm not understanding properly. Or do you mean a more gradual transfer at circa apex from braking to throttle?
>> Edited by pib on Tuesday 1st February 04:13
fergus said:
a cheeky bit of left foot trail braking will also help transfer the weight onto the front of the car whilst maintaining the drive. or you can give the brakes a quick jab, but this may well have the front end shooting towards the apex of the corner as the front wheels regain their grip (through the sudden weight transfer), with the rear then going light and coming round on you.
.
How can left foot braking on a rwd car improve the turn-in of the front if you've still got the power on? If your front tyres have a large slip angle, why would you want to run even further outside the grip circle by applying the brake .. with the throttle on all you'll do is increase the understeer and probably lock teh front wheels.
left foot braking whilst still on the power is fine in fwd cars, in rwd cars it can be useful for controlling turn-in through a slalom, but only if you take power away from the rear wheels whilst you're doing it ...
more explanation needed before i agree with this point you're making here.
My preferred route for dealing with understeer on tight corners is to press on the throttle but simultaneously winding some lock off, just in case you need armfuls of opposite if the back goes further than you expect (!) .. or in faster corners to just back off he throttle slightly, wind lock off and reduce the front slip angle and just wait until the front tyres bite again, usually only fractions of a second so if you recognise the understeer fast enough this is the safest way of regianing front grip in quick corners without running out of track width IMO.
The steering will feel "glassy" and light at the point of understeer, if you wind lock off they will grip again, and then you can steer again. This is worth practicing lots to get the hang of it, so you can quickly feel the grip again - exactly the sort of thing you do on Don Palmer's Driving Developments days on the near-zero grip roundabout! Lifting the throttle a little can help, but again it depends on the speed, the conditions, the car and you need to be careful (some cars will look forward to spitting you off at high speed).
I would suggest the Alonso / Joospeed technique is probably the safest and ultimatley quickest way of dealing with understeer. If your front's wont turn when you put that much lock on, wind some off and if your Alonso, keep your TC modulated foot down and wind on as much as the car will take. Or, if your a mere mortal in a merely fast car back off the throttle a little as well to let the front dip and take a little more steering input than before.
I would agree too with the suggestion of trail braking. i.e. braking slightly further into the corner (but at reducing pressure as you get deeper into the corner) as this helps to keep the front settled and means that getting on the power will tend to bring the back round rather than push the front out.
I have often wondered why UK driver training tends to focus on the 'brake in a straight line and power round the corner' approach whereas for example the Italian schools tend to teach trail braking from a much earlier stage. Anyone know?
>> Edited by rustybin on Tuesday 1st February 08:36
I would agree too with the suggestion of trail braking. i.e. braking slightly further into the corner (but at reducing pressure as you get deeper into the corner) as this helps to keep the front settled and means that getting on the power will tend to bring the back round rather than push the front out.
I have often wondered why UK driver training tends to focus on the 'brake in a straight line and power round the corner' approach whereas for example the Italian schools tend to teach trail braking from a much earlier stage. Anyone know?
>> Edited by rustybin on Tuesday 1st February 08:36
When teaching people drift techniques many many drivers simply keep applying more lock. Its a natural thing to do unless you realise what is going on. Which is exceeding the tyres slip angle at that moment in time. There are many techniques that'll help prevent it in the first place but the first thing to learn is what to do when you get it.
The simplest solution is to reel off a bit but this very much depends on your initial steering rechnique & try again, but it requires practice to master & to be a natural thing to do. This is where the fixed hand position can help, it prevents you aplying more lock than is required & therefore makes the undoing process much easier. As opposed to a driver who has applied a turn of lock beyond the slip angle & will have great trouble finding the slip angle again.
PS: I'm not a great advocate of the fixed hand technique, but this is one time where it's helpful & will make life easier for you.
>> Edited by cptsideways on Tuesday 1st February 09:01
The simplest solution is to reel off a bit but this very much depends on your initial steering rechnique & try again, but it requires practice to master & to be a natural thing to do. This is where the fixed hand position can help, it prevents you aplying more lock than is required & therefore makes the undoing process much easier. As opposed to a driver who has applied a turn of lock beyond the slip angle & will have great trouble finding the slip angle again.
PS: I'm not a great advocate of the fixed hand technique, but this is one time where it's helpful & will make life easier for you.
>> Edited by cptsideways on Tuesday 1st February 09:01
cptsideways said:
When teaching people drift techniques many many drivers simply keep applying more lock. Its a natural thing to do unless you realise what is going on.
One thing I realisd on the 1st Lotus day I went on was that my natural steering technique (or lack of) induced oversteer.
I was steering far too much and reducing the cornering capability of the tyres. Relaxing more and steering less helped the car to turn in a much tighter radius.
We also began to learn trail breaking but it's quite a difficult technique to pick up - there's a fine point between unsettling the car and the back end coming round (not transferring enough weight to the front) or not breaking too hard and having chronic understeer.
This didn't appear to be a great technique for carrying maximum speed through/out of a turn but useful when you've take too much speed into it or for the 1st half of a chicane.
Iain
Lots of in depth replies, but I feel perhaps the prob is simply greasy roads & too high corner entry speeds.
Slow in & then boot it out with the tail wagging- be ready to apply a bit of opp lock & I'd say you will have no further issues.
I've no idea of your driving style or your driving standards, but a mate of mine used to moan about understeer in his rwd wagon, yet he would just pile into bends far too quickly & then squeal round 'em, all the time complaining that the car was sh*te. All that was wrong was that the goon needed to learn how to drive properly.
>> Edited by iguana on Tuesday 1st February 12:11
Slow in & then boot it out with the tail wagging- be ready to apply a bit of opp lock & I'd say you will have no further issues.
I've no idea of your driving style or your driving standards, but a mate of mine used to moan about understeer in his rwd wagon, yet he would just pile into bends far too quickly & then squeal round 'em, all the time complaining that the car was sh*te. All that was wrong was that the goon needed to learn how to drive properly.
>> Edited by iguana on Tuesday 1st February 12:11
Some excellent responses here discussing aspects that in the UK you probably only ever think about if you are an enthusiast. It's interesting to hear that the Italians actually teach trail braking. No reference at all in the index of my copy of Roadcraft. 
Understeering - and front wheel skids in general - were something I began to understand better, as a younger driver, after reading an article about Paddy Hopkirk on the Monte Carlo rally back in the 60's.
The story described how his Mini Cooper was heading down an ice covered mountainside at about 70 mph with the speedo showing zero. To have any control at all he had to judge the revs versus gearing required to get the wheels rotating at the equivalent of 70 mph once again, at which point whatever grip was possible became available once more and steering/braking might work.. (Worn studded tyres as I recall so at least SOME potential for grip at 70 on ice!)
Locking the brakes, on a wet road especially, is the same problem in essence. Once it sank in that grip and control would be more likely to return if the wheels were turning at road speed in the direction of travel my instinctive responses improved (mostly).
Trail braking, I think, needs to be a planned activity and won't be guaranteed to work as a response to an already developed situation. If you have a vehicle that tends to understeer it can be quite an effective technique for making more predictably controlled progress. Works well on RWD autos for example where the option of a quick dab on the throttle to push the back out is usually less readily available. You can do it but not much happens - maybe a little more understeer at best. But then I use left foot braking anyway in an auto so it seems quite natural to trail brake when required. The secondary benefit for autos and turbos is that you can keep the throttle partly applied and so minimize or even eliminate the lag effect when you come to accelerate out of the bend.
If I find myself understeering at all or perhaps more than expected (depends on the vehicle) on the road, then I know that I have made a mistake. OR there is a road surface problem - oil or maybe ice - that I have not spotted or anticipated. That is also a mistake but slightly more excusable in my book. Slow in, fast out is the watchword - unless you are fighting for a place on track.
Off (public) road is the place to experiment. For most people in the UK there are too few opportunities for experimenting and understanding the principles - even if they were interested in the first place. It may be different in the US though.
>> Edited by LongQ on Tuesday 1st February 16:11
Understeering - and front wheel skids in general - were something I began to understand better, as a younger driver, after reading an article about Paddy Hopkirk on the Monte Carlo rally back in the 60's.
The story described how his Mini Cooper was heading down an ice covered mountainside at about 70 mph with the speedo showing zero. To have any control at all he had to judge the revs versus gearing required to get the wheels rotating at the equivalent of 70 mph once again, at which point whatever grip was possible became available once more and steering/braking might work.. (Worn studded tyres as I recall so at least SOME potential for grip at 70 on ice!)
Locking the brakes, on a wet road especially, is the same problem in essence. Once it sank in that grip and control would be more likely to return if the wheels were turning at road speed in the direction of travel my instinctive responses improved (mostly).
Trail braking, I think, needs to be a planned activity and won't be guaranteed to work as a response to an already developed situation. If you have a vehicle that tends to understeer it can be quite an effective technique for making more predictably controlled progress. Works well on RWD autos for example where the option of a quick dab on the throttle to push the back out is usually less readily available. You can do it but not much happens - maybe a little more understeer at best. But then I use left foot braking anyway in an auto so it seems quite natural to trail brake when required. The secondary benefit for autos and turbos is that you can keep the throttle partly applied and so minimize or even eliminate the lag effect when you come to accelerate out of the bend.
If I find myself understeering at all or perhaps more than expected (depends on the vehicle) on the road, then I know that I have made a mistake. OR there is a road surface problem - oil or maybe ice - that I have not spotted or anticipated. That is also a mistake but slightly more excusable in my book. Slow in, fast out is the watchword - unless you are fighting for a place on track.
Off (public) road is the place to experiment. For most people in the UK there are too few opportunities for experimenting and understanding the principles - even if they were interested in the first place. It may be different in the US though.
>> Edited by LongQ on Tuesday 1st February 16:11
rustybin said:
I have often wondered why UK driver training tends to focus on the 'brake in a straight line and power round the corner' approach whereas for example the Italian schools tend to teach trail braking from a much earlier stage. Anyone know?
It's a long story about dynamics, etc, but in a nutshell:
The classic "slow in, fast out" technique, which encompasses braking in a straight line, was absolutely correct back in the days when the most cars were RWD with no grip. Oversteer was the problem back then.
Only in the 80's and 90's did cars develop a general penchant for understeer, particularly with the move towards FWD.
Suspension development has come on so much now that many schools are beginning to introduce LFB and TB.
But as us Brits are always harking back to the days of yore when motoring was wonderful with the smell of Castrol R, crossplys and enjoying balancing SU carbs every other weekend, we fall behind the rest of the world rather quickly.
jacobyte said:
But as us Brits are always harking back to the days of yore when motoring was wonderful with the smell of Castrol R, crossplys and enjoying balancing SU carbs every other weekend, we fall behind the rest of the world rather quickly.
That makes a lot of sense. I had assumed that they were just a little less 'risk averse'.
LongQ said:
The story described how his Mini Cooper was heading down an ice covered mountainside at about 70 mph with the speedo showing zero.
Excellent story! On a lesser note, it reminds me of a very marginal trip up the M1 last winter where I just barely made it past the very steep hills (1/100 or so) between junctions 10 and 11. On the way down I had to gradually open the throttle to pick the revs up as the road speed increased, and on the way up the far side I had to guess what speed the car was doing and gradually ease off the throttle so the back wheels would slow down as the road speed dropped off. I could just about tell when I had got it right because the car would stop weaving across the tramlines for a few seconds, until the wheels started spinning again.
GreenV8S said:
The story described how his Mini Cooper was heading down an ice covered mountainside at about 70 mph with the speedo showing zero.
Excellent story! On a lesser note, it reminds me of a very marginal trip up the M1 last winter where I just barely made it past the very steep hills (1/100 or so) between junctions 10 and 11. On the way down I had to gradually open the throttle to pick the revs up as the road speed increased, and on the way up the far side I had to guess what speed the car was doing and gradually ease off the throttle so the back wheels would slow down as the road speed dropped off. I could just about tell when I had got it right because the car would stop weaving across the tramlines for a few seconds, until the wheels started spinning again.
Yes indeed. Gentle throttle, brakes and everything else in as high a gear as you can manage.
Would-be snow heroes best advised to turn to Nordic rallying using skinny studded tyres and bouncing someone elses car off the snow walls.
Many years ago, before I was old enough to drive, we were caught in a snow storm on what was normally a 2 hour drive home. After 4 hours we were about 10 miles from home when we came to a halt in a queue of vehicles whare an artic with an empty flat bed trailer has got stuck half way up a long slight hill. Of course that meant the all the vehicle behind it were stuck as well because none of the drivers could hill start on snow - or rather the ice their attempts to start had created.
Anyway there were a few people trying to get thing moving again so I got out to help. Every single car we pushed the drivers immediately went for first gear and max revs! So we would stop pushing, walk round, get the driver to open the window, explain the idea of low revs and a high gear - second (many 3 speed boxes still back then) or third - and would they like to try again? Most learned quickly, one needed it explaining several times. But in the end we got them all past the artic. That then left a space to let the truck roll back down the hill to a slightly less sloped and relatively ice free section, from where, with a bit of pushing from about half a dozen people (heaven knows how that helped!) and some sacking under the driving wheels, we just managed to get enough momentum for it to get going well enough to complete a run to the top of the incline. The remaining vehicle that we could see, us included, were on a level section so we all had an opportunity to get moving on the flat and take a reasonable run at the slope, keeping the revs right down to avoid wheelspin no matter how bad it sounded for engine vibration!
We were about 3 or 4 cars back and made it OK. Whether anyone further back got stuck again I don't know.
Sorry for the hijack - but it all relates to degrees of maintaining grip at the tyres and the experiences cross relate to some degree with understeer experiences.
The high gear thing of course is aimed at numpties with no throttle control whatsoever .. if you can cope with adjusting your throttle according to what the wheels are doing you're better off in a low gear ..
the reasoning is that on ice / snow most cars will spin their wheels and in a high gear they'll spin quite quickly to a high angular velocity in a short space of time .. for sure the higher gearing will dull any clumsy throttle work, but ..
the tyres can only generate so much tractive effort and the key is to explore the limit of the traction to it's fullest.
If you can control the torque to the wheels in a low gear, you can control the extent and ferocity of any wheelspin that results from over-application of the throttle.
If the wheels start to spin and you're in high gear then the angular momentum prevents those wheels from slowing down again quickly, as the engine braking torque effect is also dulled by the high gearing. The use of low gears allows the engine braking torque to have maximum effect on stopping those spinning wheels as quickly as possible, so allowing you to get back on the throttle again. the whole *apply throttle / wheelspin / engine braking / no wheelspin / reapply throttle* loop is much better in a low gear.
Being in a high gear doesn't generate more traction, it only allows those with clumsy feet to not get into so much trouble .. those with talented feet are better off in a lower gear ..
IMO.
>> Edited by joospeed on Tuesday 1st February 19:22
the reasoning is that on ice / snow most cars will spin their wheels and in a high gear they'll spin quite quickly to a high angular velocity in a short space of time .. for sure the higher gearing will dull any clumsy throttle work, but ..
the tyres can only generate so much tractive effort and the key is to explore the limit of the traction to it's fullest.
If you can control the torque to the wheels in a low gear, you can control the extent and ferocity of any wheelspin that results from over-application of the throttle.
If the wheels start to spin and you're in high gear then the angular momentum prevents those wheels from slowing down again quickly, as the engine braking torque effect is also dulled by the high gearing. The use of low gears allows the engine braking torque to have maximum effect on stopping those spinning wheels as quickly as possible, so allowing you to get back on the throttle again. the whole *apply throttle / wheelspin / engine braking / no wheelspin / reapply throttle* loop is much better in a low gear.
Being in a high gear doesn't generate more traction, it only allows those with clumsy feet to not get into so much trouble .. those with talented feet are better off in a lower gear ..
IMO.
>> Edited by joospeed on Tuesday 1st February 19:22
joospeed said:
The high gear thing of course is aimed at numpties
This is exactly why I prefer a lower gear when 'making progress' in slippery conditions. A small amount of wheel spin when it is anticipated is no problem. What is far more of a problem is chugging along with a generous throttle opening in a high gear, and finding that the engine torque rises (for a constant throttle) as the engine spins up and comes on cam. At the same time the grip from the wheels drops off as the wheel spin increases, so the wheel speed becomes unstable (if it slips, it is going to slip a lot). Combine this with the extra delay in slowing the wheels down again due to higher gearing and something that might have been a bit of a twitch in a low gear suddenly develops into a major loss of control.
GreenV8s said:
The high gear thing of course is aimed at numpties
This is exactly why I prefer a lower gear when 'making progress' in slippery conditions. A small amount of wheel spin when it is anticipated is no problem. What is far more of a problem is chugging along with a generous throttle opening in a high gear, and finding that the engine torque rises (for a constant throttle) as the engine spins up and comes on cam. At the same time the grip from the wheels drops off as the wheel spin increases, so the wheel speed becomes unstable (if it slips, it is going to slip a lot). Combine this with the extra delay in slowing the wheels down again due to higher gearing and something that might have been a bit of a twitch in a low gear suddenly develops into a major loss of control.
Interesting observations and I can see the benefits for an experienced bad weather driver in a vehicle they know well. Especially a sports oriented vehicle with precise and responsive controls.
You're right about the numpty bit as well - exactly the sort of people we were dealing with all those years ago.
I think the high gear thing is mainly advised so that people don't get anywhere close to the peak of the torque curve from a standing start or up to potentially quite high road speeds. Taking that as a given I like your suggestion about engine braking bringing the wheel speed back to road speed quickly though I fear that many unpractised driver would have other problems with that. So that would be the majority and realistically I would include myself not having driven on anything slippery enough to allow practise (!) for a while now. Certainly not since I moved to FWD and a turbo. But then other factors take over - traction control on the benefit side, ABS on the other.
Some numpty cars would not be much use for the engine braking concept. For example Mrs. LongQ's Xsara has some sort of device to endure the engine spins up for a while after lifting off and then subsides quite slowly. Part of the engine management to protect the cat or make smoother gear changes I suspect. Not sure why it does but it seems to add a few revs before subsiding. Whether that would make the sensitive throttle engine braking any less effective I can't be sure but my feeling is that it would not help much but is probably not a problem using the high gear technique.
GreenV8s, I understand what you have described but I'm not sure that the reality would be that you can make better progress using a lower gear rather than a higher gear in slippery conditions - unless you are geared up for ice racing or something in which case the instant throttle control to induce over or under steer could be a useful tool.
Is overall progress typically more 'good' in an inherently unstable situation (because you are anticipating the need to correct loss of traction) than by smoother off full cam progress management in a higher gear? The normal problem with engine power availability in slippery conditions it if it is too accessible surely? And usually the engine speed dictates where you are in the power band with lower revs meaning less torque, though some engines may have characteristics that would alter such a view.
So if you had an engine that offered an almost vertical torque curve to maximum output at low revs over a small rev range you might well be best off with the predictability of working in a consistent, if high, torque output. But I don't think there are many vehicles like that.
What makes it counter intuitive, for me at least, is that peaky high performance racing engines (or even road cars) tend to struggle in slippery conditions, other factors being equal. "Rain is a great leveller" is a well established consensus and as far as I know most drivers (or teams where they have control form the pits!) will use reduced revs, higher gears or (in the case of teams) re-map the engine for softer characteristics, this mimicking the concepts of using a higher gear.
So that leaves the question, for me at least, does a low gear approach in slippery conditions generally (snow may be a special case?) really provide more control AND better progress or does it provide the feeling of better control, because the driver has more obvious input, but better progress may not be a guaranteed result?
Seems like we have understeered off the original topic. Is it time to start a new thread?
My own, untrained, opinion would suggest the following, and it seems to apply to pretty much all cars, non turbo.
Appoach the bend, aiming to make the curve as straight as possible. Make an early assesment of your speed and the accuity of the bend. Select the gear that will bring the revs somewhere near the middle of the rev range, after taking the applied braking into account. As you ease the clutch up if you have a spare right foot use the throttle to match the road speed to the engine speed.
If you can see straight through the bend, there's nothing coming the other way, and no queue behind, enter the bend on the opposing side of the road if you want - in this situation it's your right of way. Plan to hit the apex on the correct side of the road, as nearly as you dare.
As you begin to apply the steering you may still have your foot on the brake. Feel for the front wheels beginning to break away. If they do, you made your mistake a while back, and are currently too fast. This is going to be a poor bend for the driver.
In this circumstance I personally tend to prefer the thought of going into the scenery sideways, and would usually be thinking of applying more steering, i.e. tighter. Resist the urge to lock the wheels at all costs. In a rear drive car, consider the possibility of gently applying more power to induce oversteer.
If you have an overwhelming sense that you're not going to make it, you are going too fast at this point you must have failed to recognise that a bend was coming early enough. This problem can cause death.
If you still can't see through the bend, look at the furthest point forward, and assume it is the apex. If you aren't part of the scenery, you are now going much slower. If you have any sense you'll be too slow. The car might be sideways, even if you are too slow.
1) Whatever happens at this point you'll have your foot on the throttle and be using it to balance the car.
If you have a well setup rear wheel drive car there will be a combination of steering force input and throttle position that will cause the front and rear to slide by the same ammount.
If the back is breaking away ease off on the throttle, if the front is breaking away ease off on the steering. If the back snatches away suddenly be ready to put in opposite lock, easing your foot away from the throttle.
2)If you have a front wheel drive car more throttle will provide less grip at the front wheels. Put in the steering you need and apply the throttle until it begins to compromise the feel of the steering.
In both circumstances a change in either steering or throttle will probably necesitate a change in the other.
As soon as you see the furthest visible point of the bend moving away from you, it is opening up, and this is the happy point where the tyres can cope with more speed. Ease off on the steering force, and apply more throttle.
Use the ability to slide the tyres as a way of loosing the kinetic energy of the vehicle. Ideally, to achieve the fastest speed one should never slide through any bend.
Try it out first where no-one is going to get hurt. Be delicate, and enjoy it.
If one is in a race the principals are the same but the inputs are more violent, to achieve greater speed (later braking and so on). The faster you put the inputs into the car, the faster it will bite you back.
Whatever you do, if it's not doing what you think it should, ease off gently with whatever caused the difficulty. Build up to the violent inputs.
Can you build me a "Parabolica" on the way to work Mr Blair?
>> Edited by dilbert on Wednesday 2nd February 03:23
>> Edited by dilbert on Wednesday 2nd February 03:25
Appoach the bend, aiming to make the curve as straight as possible. Make an early assesment of your speed and the accuity of the bend. Select the gear that will bring the revs somewhere near the middle of the rev range, after taking the applied braking into account. As you ease the clutch up if you have a spare right foot use the throttle to match the road speed to the engine speed.
If you can see straight through the bend, there's nothing coming the other way, and no queue behind, enter the bend on the opposing side of the road if you want - in this situation it's your right of way. Plan to hit the apex on the correct side of the road, as nearly as you dare.
As you begin to apply the steering you may still have your foot on the brake. Feel for the front wheels beginning to break away. If they do, you made your mistake a while back, and are currently too fast. This is going to be a poor bend for the driver.
In this circumstance I personally tend to prefer the thought of going into the scenery sideways, and would usually be thinking of applying more steering, i.e. tighter. Resist the urge to lock the wheels at all costs. In a rear drive car, consider the possibility of gently applying more power to induce oversteer.
If you have an overwhelming sense that you're not going to make it, you are going too fast at this point you must have failed to recognise that a bend was coming early enough. This problem can cause death.
If you still can't see through the bend, look at the furthest point forward, and assume it is the apex. If you aren't part of the scenery, you are now going much slower. If you have any sense you'll be too slow. The car might be sideways, even if you are too slow.
1) Whatever happens at this point you'll have your foot on the throttle and be using it to balance the car.
If you have a well setup rear wheel drive car there will be a combination of steering force input and throttle position that will cause the front and rear to slide by the same ammount.
If the back is breaking away ease off on the throttle, if the front is breaking away ease off on the steering. If the back snatches away suddenly be ready to put in opposite lock, easing your foot away from the throttle.
2)If you have a front wheel drive car more throttle will provide less grip at the front wheels. Put in the steering you need and apply the throttle until it begins to compromise the feel of the steering.
In both circumstances a change in either steering or throttle will probably necesitate a change in the other.
As soon as you see the furthest visible point of the bend moving away from you, it is opening up, and this is the happy point where the tyres can cope with more speed. Ease off on the steering force, and apply more throttle.
Use the ability to slide the tyres as a way of loosing the kinetic energy of the vehicle. Ideally, to achieve the fastest speed one should never slide through any bend.
Try it out first where no-one is going to get hurt. Be delicate, and enjoy it.
If one is in a race the principals are the same but the inputs are more violent, to achieve greater speed (later braking and so on). The faster you put the inputs into the car, the faster it will bite you back.
Whatever you do, if it's not doing what you think it should, ease off gently with whatever caused the difficulty. Build up to the violent inputs.
Can you build me a "Parabolica" on the way to work Mr Blair?
>> Edited by dilbert on Wednesday 2nd February 03:23
>> Edited by dilbert on Wednesday 2nd February 03:25
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