Cornering Basics Part 5 - Controlling the Car
Discussion
Of course, the most interesting roads don’t just go left and right, they go up and down as well. So does the technique need to change when approaching a bend on a significant incline? The issues I have in mind are:
a) When tackling a sharp bend on a steep downhill, any application of throttle can have you travelling much quicker than you might have planned. I tend to stay away from the accelerator until I’m past the apex and the bend is opening up.
b) Conversely, when going uphill around a sharp bend some acceleration is necessary but if pushing on it’s easy to generate understeer as acceleration adds to the weight transfer to the back axle. I’ve tried my best effort at the rally technique of approaching fast and throwing the car into the bend and then applying lots of power to break the back away. It’s great when it works but is hardly suitable when anyone else is about!
Clearly, it’s still all about managing the weight transfer but hills add an additional complication to think about.
a) When tackling a sharp bend on a steep downhill, any application of throttle can have you travelling much quicker than you might have planned. I tend to stay away from the accelerator until I’m past the apex and the bend is opening up.
b) Conversely, when going uphill around a sharp bend some acceleration is necessary but if pushing on it’s easy to generate understeer as acceleration adds to the weight transfer to the back axle. I’ve tried my best effort at the rally technique of approaching fast and throwing the car into the bend and then applying lots of power to break the back away. It’s great when it works but is hardly suitable when anyone else is about!
Clearly, it’s still all about managing the weight transfer but hills add an additional complication to think about.
gdaybruce said:
a) When tackling a sharp bend on a steep downhill, any application of throttle can have you travelling much quicker than you might have planned. I tend to stay away from the accelerator until I’m past the apex and the bend is opening up.
Yes, a slightly different technique is required for bends on steep hills, but the principle of accelerating through the corner is still valid - it's just the execution which is slightly different.Some downhill bends will require braking, followed simply by a release of the brake pedal on turn-in. The downhill gradient will be enough to cause the car to accelerate slightly without any application of the throttle until, as you say, the bend opens up from the apex.
On steep downhill roads where there are a series of bends, you might even need to keep the brakes on around the corners, using the principle of braking more firmly in between corners, and less firmly through the corners. The car will still be accelerating very slightly even with some brake application, but modulating the brake pedal pressure can help maintain maximum balance.
gdaybruce said:
b) Conversely, when going uphill around a sharp bend some acceleration is necessary but if pushing on it’s easy to generate understeer as acceleration adds to the weight transfer to the back axle. I’ve tried my best effort at the rally technique of approaching fast and throwing the car into the bend and then applying lots of power to break the back away. It’s great when it works but is hardly suitable when anyone else is about!
It all comes down (again!) to balance and a degree of "feel". On an uphill stretch, less braking is required - and sometimes no braking - because the gradient will slow you sufficiently well using only acceleration sense. You're already pressing the gas pedal due to the uphill, so it often feels much more natural to accelerate early into uphill bends.Mid-bend crests add a further interesting dimension, particularly if you're pressing on. Experiencing the car "going light" just as you're fully committed to a quick bend can suddenly require your full attention!
Jonsv8 said:
The weight transfer will be very different though due to gravity v power or braking. Downhill gentle braking but still physically accelerating will still have a forward weight bias in the car and as such you won't get the rear steer effect.
Thats why I advise relaxing or releasing the brakes on turn-in. There will always be a forward weight bias due to the incline, but you can manage it to your best advantage through intelligent use of the brakes. Releasing the brakes and letting gravity do the accelerating will still transfer some weight towards the rear - just not as much as through normal acceleration.I think the best thing is to learn an appreciation for the balance of the car and the grip at all four corners (or at least front:rear) and then use the accelerator, brakes and steering to keep it optimal at all times. The trouble with making rules for each situation is that there are always exceptions and no two corners or hills are the same.
One thing I was taught by a Police driver trainer, in a mega shortened version of R U Locals brilliant OP is
SLOW IN....FAST OUT.....FAST IN....s
t OUT....!
Simples really......a car IS more stable when gently PULLING around a corner.
He is not advocating wheel spinning into and out of bends, he is suggesting you loose the speed first, select the gear you require for that speed, and balance the car with the gas pedal as is fit for that bend, at that time, depending on many factors such as the weather, road surface dry/wet/icy/damp, other road users, your car weight...yes it does change depending on fuel load, what's in the boot, how many passengers......tyre wear, your mood, tired/on prescription drugs/drugs/an alcoholic drink (or 2 in your system)....and most importantly most of us actually think we are better drivers than we really are..........
SLOW IN....FAST OUT.....FAST IN....s
t OUT....!Simples really......a car IS more stable when gently PULLING around a corner.
He is not advocating wheel spinning into and out of bends, he is suggesting you loose the speed first, select the gear you require for that speed, and balance the car with the gas pedal as is fit for that bend, at that time, depending on many factors such as the weather, road surface dry/wet/icy/damp, other road users, your car weight...yes it does change depending on fuel load, what's in the boot, how many passengers......tyre wear, your mood, tired/on prescription drugs/drugs/an alcoholic drink (or 2 in your system)....and most importantly most of us actually think we are better drivers than we really are..........
The benefits of accelerating (gently) through a corner and then accelerating (hard) out is quite pronounced on most RWD cars that I have driven. It is a bit less acute on FWD cars, which seem to me to corner best under steady speed (i.e. still increasing throttle but only a bit). I may be wrong, but slow in/fast out seems to work best with the drive at the rear - probably to take advantage of the shift backwards under acceleration.
The only car that I have driven fast which needed trail braking was a 3er on standard suspension - it would NOT turn in for low speed corners without braking to the apex. But I have never really needed it otherwise - corners that would benefit from trail braking in a sorted RWD car don't tend to be well-sighted enough for those kind of speeds to be safe.
I would trail brake into one 2nd gear corner that I know if I could safely exit at 40-50mph, but the sight lines aren't good enough to make that safe; so getting all the braking done in a straight line is good enough.
The only car that I have driven fast which needed trail braking was a 3er on standard suspension - it would NOT turn in for low speed corners without braking to the apex. But I have never really needed it otherwise - corners that would benefit from trail braking in a sorted RWD car don't tend to be well-sighted enough for those kind of speeds to be safe.
I would trail brake into one 2nd gear corner that I know if I could safely exit at 40-50mph, but the sight lines aren't good enough to make that safe; so getting all the braking done in a straight line is good enough.
Being on the throttle is good advice, because a car on a trailing throttle is quite unstable, but it's worth pointing out the differences between holding a steady throttle (i.e. some throttle needed to counteract the drag a car generates when cornering and maintan a constant speed) and actually accelerating through a corner. This is important because accelerating throughout a bend (and by 'accelerating' I mean increasing speed, not pushing the throttle) is the start of probably the most common driving error that I've seen when instructing on track and I would say is responsible for the vast majority of accidents I've seen on You Tube from the Nurburgring, track days and public road silliness. That error is a three stage process:
a) the driver accelerates round the corner, which lightens the front of the car and makes it tend towards understeer.
b) To retain the car's cornering line in the presence of that slight understeer, the driver increases the steering lock.
c) repeat a and b for the duration of the corner.
a, b & c combined give you a driver who steers more and more as a corner progresses, and then they unwind all the lock in a jerk at the end of the corner. You see this a lot on the Top Gear celebrity laps.
Many drivers drive like this all the time and never have any problems, but when a) they try to go faster, b) if a bend takes them by surprise (lack of observation) or c) they go a bit too fast around a corner (again, lack of observation and judgement), they find themselves running out of road and they then back off the throttle, (and/or give the car even more lock). What happens then is that weight transfers onto the front wheels, which have an inappropriate amount of lock on for the cornering radius their car is engaged in. That increased grip on the inappropriately angled front wheels pulls the front of the car into the bend sharply, which coupled with the lightly loaded rear tyres (a consequence of backing off) often gives instant oversteer. That's what is referred to succinctly and commonly as "lift of oversteer", but contrary to common belief, at its route it's simply a driving error. Sure, it's more likely in a car with a neutral setup, or a lightly loaded front end prone to understeer and a heavy pendulous rear end (e.g. 911, MR2 mk3, Elise on both counts - all of which have a reputation for LOO), but a good driver will simply never experience LOO, even if they lift off mid corner driving fast, because a good driver will always have an appropriate amount of lock on and be managing the balance of the car. There are plenty of racing corners around the world that require the driver to start slowing the car whilst still cornering, even if the line the driver takes minimises this, and obviously every car doesn't spin when they get to that corner!
a) the driver accelerates round the corner, which lightens the front of the car and makes it tend towards understeer.
b) To retain the car's cornering line in the presence of that slight understeer, the driver increases the steering lock.
c) repeat a and b for the duration of the corner.
a, b & c combined give you a driver who steers more and more as a corner progresses, and then they unwind all the lock in a jerk at the end of the corner. You see this a lot on the Top Gear celebrity laps.
Many drivers drive like this all the time and never have any problems, but when a) they try to go faster, b) if a bend takes them by surprise (lack of observation) or c) they go a bit too fast around a corner (again, lack of observation and judgement), they find themselves running out of road and they then back off the throttle, (and/or give the car even more lock). What happens then is that weight transfers onto the front wheels, which have an inappropriate amount of lock on for the cornering radius their car is engaged in. That increased grip on the inappropriately angled front wheels pulls the front of the car into the bend sharply, which coupled with the lightly loaded rear tyres (a consequence of backing off) often gives instant oversteer. That's what is referred to succinctly and commonly as "lift of oversteer", but contrary to common belief, at its route it's simply a driving error. Sure, it's more likely in a car with a neutral setup, or a lightly loaded front end prone to understeer and a heavy pendulous rear end (e.g. 911, MR2 mk3, Elise on both counts - all of which have a reputation for LOO), but a good driver will simply never experience LOO, even if they lift off mid corner driving fast, because a good driver will always have an appropriate amount of lock on and be managing the balance of the car. There are plenty of racing corners around the world that require the driver to start slowing the car whilst still cornering, even if the line the driver takes minimises this, and obviously every car doesn't spin when they get to that corner!
ORD said:
The only car that I have driven fast which needed trail braking was a 3er on standard suspension - it would NOT turn in for low speed corners without braking to the apex.
Interesting that you say that, the car I have tried the suggested method out with is a 325ti, even though I was not driving fast it does not feel right.I was also thinking along Rob's line of thought in that there is a difference between accelerating and using the accelerator to just maintain speed. Though of course technically when cornering you are always accelerating irrespective of what it happening to your speed.
Given we are not talking about speeds that approach the limits of grip, do fwd cars feel better when there is some drive pulling the car into a corner? Red would tend to feel like the car is being pushed wide perhaps?
RobM77 said:
The other thing worth saying is that you can probably cause more damage than good trying to follow rules on car balance; a driver who doesn't understand or can't feel a car's balance may actually be better off releasing the brakes before turning into a corner than he would trying to exchange one for the other on turn-in, because as soon as you do the latter and start to control the car properly, you can cause quite dramatic instability in the car.
All of these arguments that point towards learning to feel a car and control it accordingly, rather than follow rules, is probably why little of this advice ever made it into the core Roadcraft/IAM/RoSPA syllabi, because they do tend to be based around rules (or more controversially, can I say 'dogma'!).
Agreed. When people understand the concept of balance and put it into practice enough for it to become ingrained, their riding and driving is transformed. All of these arguments that point towards learning to feel a car and control it accordingly, rather than follow rules, is probably why little of this advice ever made it into the core Roadcraft/IAM/RoSPA syllabi, because they do tend to be based around rules (or more controversially, can I say 'dogma'!).
The "rules" of balance and throttle control then supersede/over-ride the various "rules" of cornering (from a control point of view) laid down by various Advanced courses.
Twist of the wrist 2, an excellent motorbike riding guide, makes this point.
Ps. I was recently driven by a taxi driver with IAM badge on the grille and and a big IAM key ring on his ignition card. Besides the tailgating, his driving and car control were notably poor.
MC Bodge said:
RobM77 said:
The other thing worth saying is that you can probably cause more damage than good trying to follow rules on car balance; a driver who doesn't understand or can't feel a car's balance may actually be better off releasing the brakes before turning into a corner than he would trying to exchange one for the other on turn-in, because as soon as you do the latter and start to control the car properly, you can cause quite dramatic instability in the car.
All of these arguments that point towards learning to feel a car and control it accordingly, rather than follow rules, is probably why little of this advice ever made it into the core Roadcraft/IAM/RoSPA syllabi, because they do tend to be based around rules (or more controversially, can I say 'dogma'!).
Agreed. When people understand the concept of balance and put it into practice enough for it to become ingrained, their riding and driving is transformed. All of these arguments that point towards learning to feel a car and control it accordingly, rather than follow rules, is probably why little of this advice ever made it into the core Roadcraft/IAM/RoSPA syllabi, because they do tend to be based around rules (or more controversially, can I say 'dogma'!).
The "rules" of balance and throttle control then supersede/over-ride the various "rules" of cornering (from a control point of view) laid down by various Advanced courses.
Twist of the wrist 2, an excellent motorbike riding guide, makes this point.
Ps. I was recently driven by a taxi driver with IAM badge on the grille and and a big IAM key ring on his ignition card. Besides the tailgating, his driving and car control were notably poor.
Interesting read, thanks for the information OP. The inherent rear wheel steering was an interesting point.
Definitely helped my understanding of a cars balance. I was playing around tonight on a few bends I usually just coast through and found that just maintaining speed with a little bit of throttle made the car feel much more planted. Definitely reduced the feeling of understeer mid corner.
I would like to get some proper driver training at some point but I think there's still a lot fundamentals I need to understand first. I have a good understanding of tyre traction levels and the effect of cornering forces and have been reading about slip angles recently. Just need to read a bit more into suspension and geometry.
Definitely helped my understanding of a cars balance. I was playing around tonight on a few bends I usually just coast through and found that just maintaining speed with a little bit of throttle made the car feel much more planted. Definitely reduced the feeling of understeer mid corner.
I would like to get some proper driver training at some point but I think there's still a lot fundamentals I need to understand first. I have a good understanding of tyre traction levels and the effect of cornering forces and have been reading about slip angles recently. Just need to read a bit more into suspension and geometry.
CarAbuser said:
Interesting read, thanks for the information OP. The inherent rear wheel steering was an interesting point.
Definitely helped my understanding of a cars balance. I was playing around tonight on a few bends I usually just coast through and found that just maintaining speed with a little bit of throttle made the car feel much more planted. Definitely reduced the feeling of understeer mid corner.
I would like to get some proper driver training at some point but I think there's still a lot fundamentals I need to understand first. I have a good understanding of tyre traction levels and the effect of cornering forces and have been reading about slip angles recently. Just need to read a bit more into suspension and geometry.
Out of interest, I did an instructing day with a PHer last year and he'd bought a new track day car and spun it quite a few times. I did my usual thing and asked him to do about ten laps with me not saying a word and just watching him settle into his usual rhythm, and it occurred to me that he never once touched the throttle through a corner. For the second session I asked him to try just holding a steady throttle from turn-in to exit and he immediately grew a huge smile and announced how the car felt much more stable. Timing's banned at track days, but I reckon he might have gained as much as 5-10 seconds a lap just by doing that, and sure enough, we didn't spin once that day, or even get any oversteer.Definitely helped my understanding of a cars balance. I was playing around tonight on a few bends I usually just coast through and found that just maintaining speed with a little bit of throttle made the car feel much more planted. Definitely reduced the feeling of understeer mid corner.
I would like to get some proper driver training at some point but I think there's still a lot fundamentals I need to understand first. I have a good understanding of tyre traction levels and the effect of cornering forces and have been reading about slip angles recently. Just need to read a bit more into suspension and geometry.
RobM77 said:
That's interesting, because two of the most dangerous drivers I know claim to be IAM trained. Perhaps it's like those people in academia who are exam passing machines but never truly understand things? Having an inherent feeling and sympathy for the balance and grip of a car is a crucial skill, but I must confess I haven't got a clue how anyone would go about teaching it.
The aforementioned " Twist of the Wrist 2" and "Bondurant on Perforfmance Driving"(a book with some very good nuggets of information) cover the subject of balance quite well. A lot of people seem to be missing the point about IAM/ROSPA, especially in the context of "Cornering Basics". Those organisations are not meant to be turning the naturally talented into driving gods. They exist so that ordinary drivers can check that their post DSA test learning is progressing satisfactorily, most importantly their observers and examiners might spot bad habits that the driver had got into without being aware of them. If they do this, the driver, however incompetent, is still better than they would have been had they not taken the training, and this makes the exercise worthwhile.
I've driven virtually all configurations of cars at one time or another. Rear engine RWD, mid engine RWD, front engine RWD, front engine FWD and front engine 4WD, on both road and (occasionally) track, all without incident. Despite this I genuinely have no idea how to judge the 'balance' of a car beyond providing what seems the right amount of accelerator pressure on a corner. I certainly don't have the foggiest notion of what I could usefully do differently between RWD 4WD and FWD, they all seem the same to me.
But this does not mean that IAM membership and ROSPA gold hasn't been worthwhile because when it comes to not crashing on the road it's hazard awareness that matters. Primarily in terms of anticipating the possible actions of other road users. Which is why track training is basically irrelevant.
For every RTA that could have been avoided if only the driver had possessed a better feel for the optimum front/rear weight distribution allowing for the polar moment of inertia of the drivetrain configuration. I suspect at least a dozen have been actually caused by drivers practising manipulating the balance through using track techniques on the road.
I've driven virtually all configurations of cars at one time or another. Rear engine RWD, mid engine RWD, front engine RWD, front engine FWD and front engine 4WD, on both road and (occasionally) track, all without incident. Despite this I genuinely have no idea how to judge the 'balance' of a car beyond providing what seems the right amount of accelerator pressure on a corner. I certainly don't have the foggiest notion of what I could usefully do differently between RWD 4WD and FWD, they all seem the same to me.
But this does not mean that IAM membership and ROSPA gold hasn't been worthwhile because when it comes to not crashing on the road it's hazard awareness that matters. Primarily in terms of anticipating the possible actions of other road users. Which is why track training is basically irrelevant.
For every RTA that could have been avoided if only the driver had possessed a better feel for the optimum front/rear weight distribution allowing for the polar moment of inertia of the drivetrain configuration. I suspect at least a dozen have been actually caused by drivers practising manipulating the balance through using track techniques on the road.
RobM77 said:
Out of interest, I did an instructing day with a PHer last year and he'd bought a new track day car and spun it quite a few times. I did my usual thing and asked him to do about ten laps with me not saying a word and just watching him settle into his usual rhythm, and it occurred to me that he never once touched the throttle through a corner. For the second session I asked him to try just holding a steady throttle from turn-in to exit and he immediately grew a huge smile and announced how the car felt much more stable. Timing's banned at track days, but I reckon he might have gained as much as 5-10 seconds a lap just by doing that, and sure enough, we didn't spin once that day, or even get any oversteer.
A lot of people may have fallen into the same trap as me with regards to letting off the power during corners. It seems counter-intuitive to get on the throttle while cornering until you think a little deeper into vehicle balance and also realise that no throttle on a flat corner is decelerating rather than maintaining speed. Same with driving in the wet and avoiding aquaplaning by keeping on the power.CarAbuser said:
A lot of people may have fallen into the same trap as me with regards to letting off the power during corners. It seems counter-intuitive to get on the throttle while cornering until you think a little deeper into vehicle balance and also realise that no throttle on a flat corner is decelerating rather than maintaining speed. Same with driving in the wet and avoiding aquaplaning by keeping on the power.
This is why it is good to drive on a skid pan, wet grass or snow and learn about what happens. Most people only learn as they have a crash.anonymous said:
[redacted]
I think it's pretty close to the point of the discussion.Advanced driving is such a broad term, but I've been clear on two points in the post title. Point one is that it covers the basics of good cornering. Point two is that it is the fifth post in a series looking at all aspects of basic cornering skills.
Of course there are more advanced techniques, depending on your skill level, experience, the type of car you drive, whether you're on road or track etc, etc.
But for a large proportion of drivers, the simple change from being off the throttle through a corner, to introducing a little acceleration through a corner can be an absolute revelation.
Lets not get too tied up in the minutae of trail-braking, balancing a car on the brakes on turn-in etc. these techniques all have their place, but in my series of posts on cornering basics, If a few drivers have learned to set their speed correctly for a corner, pick out a good line and apply some acceleration whilst cornering, then there's probably a few more better drivers on the road, which isn't a bad thing.
Perhaps I should do a post on very advanced cornering for those of you who feel this series is too basic?
Edited by R_U_LOCAL on Saturday 2nd May 13:22
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