Reaction to skids in an ESP-equipped car

[TripleS]

How often do ABS, ESP, Traction Control actually ever get called into play in real-life real-road driving? I can only think of two occasions in the last five years or so when ABS kicked in (both fairly genuine emergencies) and Traction Control maybe once when it was a bit greasy underfoot.

My current car, which I've had for almost 14 years, does have ABS, (but none of the other systems you mention), and apart from winter conditions, in which it has worked a few times when I'd rather it hadn't, it has hardly come into action at all. The only times it has been activated, and then only briefly, has been if I put wheels onto a muddy grass verge etc. when meeting another vehicle in a narrow country road at low speed. On normal surfaces, dry or wet, it hasn't come into action at all.

[akirk]

How often do ABS, ESP, Traction Control actually ever get called into play in real-life real-road driving? I can only think of two occasions in the last five years or so when ABS kicked in (both fairly genuine emergencies) and Traction Control maybe once when it was a bit greasy underfoot.

on my z3 - not unknown - a few times a year, usually on loose gravel (living in the Cotswold water park there is a lot of spilt gravel) - even at 5 - 10 miles per hour it can come on... hate to think what the car would do on ice!

in normal driving - not used...

Alasdair

[Tosh]

My car has ABS, Traction Control, Vehicle Stability Control, Variable Gear Ratio Steering, Electronic Brake Force Distribution and Brake Assist.

In the short time I've owned this car I've never had to activate these systems but knowing that they are there does provide a level of reassurance that should things get a bit out of hand there is a level of assistance. Even with that level of reassurance there is no way I would rely on them to keep me safe. Those systems are the last resort.

[TripleS]

If the speed is not in excess of 30% of the maximum speed otherwise possible without sliding - ESP should prevail. It does not sound like much, but those 30% are quite a lot!

I thought there was something wrong with what you said there, so I queried it, but there seems to have been no reply.

Is it right after all, because if it is, I don't understand what you're telling us; and I need educating.

[waremark]

If the speed is not in excess of 30% of the maximum speed otherwise possible without sliding - ESP should prevail. It does not sound like much, but those 30% are quite a lot!

I thought there was something wrong with what you said there, so I queried it, but there seems to have been no reply.

Is it right after all, because if it is, I don't understand what you're telling us; and I need educating.

I thought it was clear that he meant 130%. His English is astonishingly good.

I would love the opportunity to find these things out using someone else's tyres on wide open spaces. When attending a Car Limits day at North Weald, Andy Walsh has you taking one particular bend many times seeing how fast you can take it without leaving the (simulated) edge of the road. When I got to a speed (ESP off) at which I could not stay on the road I tried turning the ESP on to see if it would enable me to stay on the road at that speed. No. However, that was when I was expecting to skid and in practice at controlling it. I certainly want to have ESP to help me if I have to deal with an unexpected emergency. It can make what would otherwise be a disaster quite undramatic.

[TripleS]

If the speed is not in excess of 30% of the maximum speed otherwise possible without sliding - ESP should prevail. It does not sound like much, but those 30% are quite a lot!

I thought there was something wrong with what you said there, so I queried it, but there seems to have been no reply.

Is it right after all, because if it is, I don't understand what you're telling us; and I need educating.

I thought it was clear that he meant 130%. His English is astonishingly good.

I would love the opportunity to find these things out using someone else's tyres on wide open spaces. When attending a Car Limits day at North Weald, Andy Walsh has you taking one particular bend many times seeing how fast you can take it without leaving the (simulated) edge of the road. When I got to a speed (ESP off) at which I could not stay on the road I tried turning the ESP on to see if it would enable me to stay on the road at that speed. No. However, that was when I was expecting to skid and in practice at controlling it. I certainly want to have ESP to help me if I have to deal with an unexpected emergency. It can make what would otherwise be a disaster quite undramatic.

OK, but if EPS can get us through a bend with 30% excess speed, that is indeed very impressive. That's what I would call a big margin: but then I don't think I have ever disputed its capabilities and benefits.

[stefan einz]

ESP has been developed with the average motorist in mind, one with no concept of handling or skid control. In order for ESP to kick in and do its job all you have to do is point the car in the direction you need to go. Hitting the brakes or accelerator will have no effect to the stability as the ESP will take over and maintain the car on the steering course you want. Using conventional skid control techniques of reducing steering angle in an understeer slide or opposite lock to correct a rear wheel slide will actually prevent the ESP from activating as it will not detect a slide.

If you watch Mark Kendrick's Bespoke Driving DVD, High Performance Roadcraft, he has a section detailing this information.

The OP's original question is a very good one. And the answer from my perspective is that it very much depends on the system in the car. I've quoted the post above because I think it is sensible answer that would apply to many systems fitted to modern cars. But I don't think it is entirely correct for all types of situation.

Specifically, in the oversteering example, ESP systems in performance cars are now, in many cases, tuned to allow a degree of slip and work with a driver who is countersteering, In fact, some systems are so clever that they anticipate the grip level by matching what the sensors are recording against pre-programmed maps (e.g. Ferrari F12 as per its handbook). They modulate the engine's torque and electronic differentials (if fitted) to optimise traction and performance. In such cases, if the car begins to oversteer under power, the best thing is to "keep one's foot in", because the system will meter the power precisely for the available grip and allowed slip.

Clearly, I appreciate this does not apply to most everyday cars, but it will apply to a significant minority of performance cars on the road. Moral - best way to understand how to work with your car's systems is to have a play on a proving ground and experiment.

Cheers

[waremark]

In fact, some systems are so clever that they anticipate the grip level by matching what the sensors are recording against pre-programmed maps (e.g. Ferrari F12 as per its handbook). They modulate the engine's torque and electronic differentials (if fitted) to optimise traction and performance. In such cases, if the car begins to oversteer under power, the best thing is to "keep one's foot in", because the system will meter the power precisely for the available grip and allowed slip.

Clearly, I appreciate this does not apply to most everyday cars, but it will apply to a significant minority of performance cars on the road. Moral - best way to understand how to work with your car's systems is to have a play on a proving ground and experiment.

Cheers

Do Ferrari and McLaren have the same approach to this? Are both quicker on track using the electronic systems than with the systems turned off, even for the most skilled drivers? Does using the systems diminish the satisfaction for a driver at your skill level (noted from the other thread that your most outstanding cars are purer). What do they do differently in race or track mode than in sports mode?

[stefan einz]

In fact, some systems are so clever that they anticipate the grip level by matching what the sensors are recording against pre-programmed maps (e.g. Ferrari F12 as per its handbook). They modulate the engine's torque and electronic differentials (if fitted) to optimise traction and performance. In such cases, if the car begins to oversteer under power, the best thing is to "keep one's foot in", because the system will meter the power precisely for the available grip and allowed slip.

Clearly, I appreciate this does not apply to most everyday cars, but it will apply to a significant minority of performance cars on the road. Moral - best way to understand how to work with your car's systems is to have a play on a proving ground and experiment.

Cheers

Do Ferrari and McLaren have the same approach to this? Are both quicker on track using the electronic systems than with the systems turned off, even for the most skilled drivers? Does using the systems diminish the satisfaction for a driver at your skill level (noted from the other thread that your most outstanding cars are purer). What do they do differently in race or track mode than in sports mode?

I think in both cars the most skilled drivers are quicker (in the dry) with the systems off. But remember in the McLaren that torque steer is always operating, as is the e-diff in modern Ferraris.

In the wet, I can't say for sure, but I'd suspect the cars are quicker with some (limited) traction control. That said, when I was Fiorano earlier this year we did a little auto test (25 second circuit in 1st and 2nd gear) in each of the modes in turn (2 laps in each mode). I was quickest with all systems off; next quickest with CT off and so on. For some of the less experienced drivers, they were quicker (not surprisingly) with the systems on (mainly because they would spin without the systems!).

Reference the modes, in the Ferrari the Race, CT off and ESC modes all progressively remove elements of the system control. So in Race mode, all systems are on, but allow quite a large degree of slip as compared to Sport or Wet. In CT off mode, stability control is off, the e-diff in set to its most aggressive setting, but traction control remains In ESC off mode, just the e-diff is left - it is the "you're on your own mode"!