ESP systems from BMW, AMG, Nissan, Porsche put to the test

Rossen Gargolov
ESP systems from BMW, AMG, Nissan, Porsche in the test
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I n these Circles is ESP as a brake on fun. Electronic stability program - the very name does not match our view of driving a car. Because we drive here, I emphasize: drive! On your own initiative, independent, without a know-it-all computer in the background that constantly messes up. Period!

Racing recognized the advantages of ESP

Up until a few years ago, this point of view was still quite unreserved. When it came to performance, at the latest, when it came to maximum performance on the racetrack, humans were always faster than machines, simply because electronics were too attached to the service of safety. Now, however, the tide is starting to turn - whether you like it or not.

You just have to look at the development: In the beginning, ESP was a cane against inadequacies, a makeshift solution for cars that move away from Letting moose fall or suddenly doing pirouettes in motorway bends - basically a good thing.

In the following years, however, it became more and more a panacea, became a basic requirement for driving safety - and therefore often a fig leaf for a half-baked vote. But then racing discovered the advantages of the technology, instrumentalized it for its own purposes, in order to transfer it back into series production - as a performance tool that no longer just regulates the handling, but contours it. That's the theory.

ESP as the nucleus of further dynamic features

The difficulty: With a simple on-off The balancing act between restriction and incentive can hardly be implemented in a systematic manner, which is why intermediate stages were installed in most sporty cars, which are then called handling mode, sport or dynamic program.

And even within this subculture of control electronics already a development. At first, these intermediate stages were simply a long line. Motto: Do ​​it - when things get tough, I'll be there and intervene. For some time now, however, they have been working constructively on the driving dynamics. And they form offshoots: electronic limited slip differentials, for example, which generate traction on the relieved wheel via control pulses, or active torque vectoring systems. This is where the braking intervention takes place - nothing else does an ESP at the end of theDay - organized in such a way that a car moves as agile as possible in and around bends.

In short: The ESP, which once went into series production as an extra item for safety fanatics, was only the nucleus for a whole bunch of dynamic features, which have since emerged from it - and will emerge.

Four athletes in the ESP test in Hockenheim

Of course, the yield of such containers also depends on the philosophy of the respective manufacturer, i.e. how a lot of freedom one expects or trusts the driver - depending on the perspective. And it depends on the effort that is put into the application. And this effort increases with the complexity of the chassis. Specifically: Such a Nissan 370Z Nismo can be used in the control electronics due to its rather analog structure - to put it casually - be much simpler than a fully electronic Porsche 911 Carrera S, whose system not only has to interact with different degrees of damper hardness, but also with roll compensation and rear-axle steering.

To unravel what happens and when it happens and how, if we had to dig deep into electrical engineering, we would have to engage in the dialogues of a growing number of control units and decipher all of that.

But since we prefer to learn by doing here, we simply have four athletes ordered to Hockenheim. Or to put it another way: It shouldn't be a dry story - although it didn't have to be that wet either.

Quite frankly: We briefly considered whether we should sell you the soaking wet route as wanted, as a purpose-sanctioned means to better disclose the functioning of the respective ESP. In truth, however, Petrus has simply beaten us one of his cheats, so that this test has to be a two-part - the prelude happens here and now in the rain.

Complicated circumstances

And this fact makes it more complicated for those present than you might think. Because almost all sports cars, regardless of whether they are sophisticated ones like the BMW M4 and Mercedes-AMG C 63 or pure-bred ones like the Porsche 911 and, in a weakened form, the Nissan 370Z, are nowadays increasingly focused on performance, which reduces their willingness to compromise. In other words: All as they stand are optimized for dry conditions - via the chassis, via the steering, especially via the tires, some more, some even more.

The route also harbors a conflict of objectives. In order to be as fast as possible here and now, you would actually have to use the rain line: brake inside, take bends over the outside lane - that is, down from the usual ideal line, therewhich becomes particularly slippery when it rains due to the abrasion that is on the cardboard.

Only that is not necessary in a specific case, more: It would even be counterproductive. Because this is not about the best time as such, but about the time differences between the ESP modes, ultimately about subtleties. And this requires continuity, especially in incontinent weather conditions. Long story: We stay on the Ochsenweg.

Nissan 370Z represents the old school

And let's start the Nissan 370Z, which represents the old school with its naturally aspirated engine, authentic steering, manual six-speed gearbox and static chassis. It's a solid car that you can feel, in your rear end and in your limbs, which is definitely an advantage in such soapy grip conditions.

Nevertheless, the first trips have a lot to do with approaching, with searching after the fine line between static and sliding friction, which can only be driven on with warm rubbed tires.

As the only one of the quartet, the 370 distinguishes only two ESP programs - on and off, with the 'off.' “Yes such a thing is. Many sports models in the VW group, for example, are notorious for the fact that they still spark in the off mode, and so is the Nissan 370Z never takes out its electronics completely. The traction control - an essential element of all ESP systems - is completely cut off, so that it can be wonderfully slid out of curves thanks to its linear power development. When braking, however, if you want to give it a slight rear twist towards the apex to avoid understeer, you can feel from the braking intervention on the front wheels that its electronics can never completely let go - or better: let go.

Means : The time is not quite as good as it could be with more laissez-faire, and yet significantly better than with fully activated ESP - which is logical. Because due to the lack of a sporting position, the stability electronics must primarily fulfill their original purpose here, namely driving safety. And she does that - typically for Asians - with a strict regiment. As soon as the rear axle greases just a little sideways, it grips.

Determined and rigorous - almost as if it wanted to educate you with it. Ergo: You have to stay away from it, drive clean, and above all not accelerate too harshly or too early, which is also possible thanks to the decent traction and the good controllability.

BMW M4 handling is missing in the wet the basis

In any case, better than in the BMW M4. In the form of the M dynamic mode, it has that electronic compromise between freedom and reason that the Nissan lacks, but its entire design is too offensive to work with it sensibly. Turn andThe key to its driving behavior is the active rear axle differential, which always shifts the torque between the rear wheels in a way that promotes agility. In the dry - we know from experience - it works splendidly: there is practically no understeer, but oversteer is omnipresent, in front of the bend, in the bend, and anyway. In the wet, however, when the rear axle, which is designed for sliding friction, also reduces the coefficient of friction of the road surface, the M4 handling lacks the basis.

When the driving aids are switched off - and switched off means switched off here - you have a lot to do , must constantly correct and, above all, weigh up how much angle is still effective. That is not without a claim, but it is feasible. For the electronics, however, the transverse drives can hardly be processed, and certainly not profitable. With the ESP activated, you can still manage to some extent, simply because the electronics largely nip the sideways movements in the bud.

The dynamic mode allows more, even more, and of course you have to reach out all the more resolutely to avoid the lean angle To become master. The problem: The moment of intervention is practically impossible to predict, and that makes handling a car that constantly swims in an angle extremely difficult.

Two tenths each between three driving modes

And yet there are only two tenths between the lap times of the three modes - far less than felt. How can that be? Well, on the one hand it is - as they say so beautifully - hopped and jumped, what you struggle with at the limit, whether with the torque limitation in the ESP modes or with wheelspin - both take propulsion and therefore time.

On the other hand, the short distance is also related to our driving style in the course of the measurements. Of course, one could always force the cars into the control areas by force, throw them into bends, let the rescue net catch them, muddle out again - and then conclude how far the stability programs are still from human ingenuity. But our aversion doesn't go that far. So we got the maximum out of each mode, drove around the ESP where necessary, or leaned on it if it worked.

C 63 with the worst sign - and still great

Nevertheless - to our collective relief - the electronics are not yet able, at least under these conditions, to stand up to an experienced pilot, let alone performance - relevant to support. Basically! Conversely, this means that with AMG and Porsche, too, the time gap increases with the degree of regulation, but within a framework that falls under the insignificant.

With the Mercedes-AMG C 63, for example, only two tenths lie between being completely bare and full of gear, but not just forhis ESP vote speaks for him as well. Nominally, it has the worst omens: it is the heaviest, the most delicate with rear tires and the one who has to process the most torque - but still has a secure footing.

Above all, the traction makes the difference: where BMW is M4 and Nissan 370Z already out of step, the locking mechanism still keeps it on. That helps in the off mode, of course, but it also helps the electronics, which have to intervene less often. Assuming the right feet, the ESP only pushes itself into the driving behavior at the entrance to a curve. Whereby jostling is almost said a bit too much, given the care it takes. The catch - in the truest sense of the word - only comes afterwards, at the transition back to self-determination, where the engine punch is sometimes released so abruptly that the 650 Nm immediately hit you back into the control range.

Porsche 911 Carrera S shines

And these are exactly the moments when the Porsche 911 shines. In contrast to the systems of the other three, all of which push their interventions very roughly and, above all, extensive into the power flow, he divides them into many fine, very short impulses. He packs, lets go, packs again - and so on. This leads to a slight jerk, but it works wonderfully - under load as well as when turning in when you spin over all fours into the curve on the soapy floor. But it also has perfect prerequisites: wide track, wide rear tires, the aforementioned driving dynamics network, steering that maintains serenity around the central position, and the highly sensitive turbo engine, which also presses its own weight onto the rear axle as a traction aid.

The logical consequence: on the one hand the very small time differences between the modes, on the other hand a clear lead over the others here - even more clearly than it will be in the dry. Probably.

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