Thursday 10th May 2012

PH Blog: passive / aggressive

Why both these cars prove that 'sport' suspension button on the dash is just a gimmick

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There's a lot of talk of electric steering ruining the feel of true drivers' cars but, to my mind, the curse of adaptive/adjustable/selectable damping is an equal threat.

And gives me an excuse to make the ludicrous juxtaposition of my £1,250 Eunos with £200K's worth of SLS Roadster. And explain what links them in spirit. Namely, great passive dampers.

No adjustable dampers here, ta

AMG is pretty much alone in having the belief in its chassis set up abilities to give its most hardcore products (CLK Black, C63, etc) non adjustable dampers that work better, and across a broader range, than most rivals' multi-mode adaptive designs. This, to my mind, worthy of far more respect than adding a button on the dash and letting the driver think he knows better than the chassis engineers. Indeed, it was explained to me by one that in at least one case - brand not disclosed, sadly - hitting the sport button initiated a 'hard' feel to appease the customer's demand for a sportier sensation, before the damping settings slowly relaxed back to the 'correct' one. Which goes to show how wrongheaded simplistic assessments of ride like 'soft' and 'firm' really are.

With a few notable exceptions I'm inclined to believe this is as much marketing tosh as is the offering of different steering 'maps' - Audi and BMW among the most obvious culprits here. Just set it up correctly and be done with it.

Again, Mercedes stands proud here and its current cars steer much more naturally than most rivals as a result. As much as 'firm' doesn't equal sporty in ride terms, 'heavy' doesn't equate to feel in steering.

Scotland really tested the P5 dampers

I'm no technical expert; my assessments of ride are purely seat of the pants and when Performance5'sDave Turner drew me lots of graphs and tried to explain the technicalities of the Sportdrive dampers he and P5's Phil had developed and were shortly to be fitted to my Eunos I didn't understand a word. But I know what I like and the quality of the damping speaks for itself, much like that on the SLS and our PH Fleet Golf GTI Edition 35, which has passive dampers rather than the ACC ones optioned onto many GTIs.

I picked my Eunos up from Performance5 just before heading up to Scotland, Phil fitting the dampers with Superpro eyelet bushings to address an NVH issue he'd been battling and ramping up the rebound damping just a tad. And at low speeds and on hard-edged bumps the Eunos might be described as a little harsh. But when the speeds pick up as, er, they did in Scotland the pay-off is revealed. And the Eunos, the SLS and the Golf all have a similar character - one that, to my tastes, feels great.

Rather than 'soft' or 'firm' I'd like to describe my personal damping preference as 'fast', a characteristic all three share. All have a natural platform in their damping and all move quickly either side of that but, more importantly, back to it, with the minimum of fuss. Yes, the car moves. But that movement is perfectly controlled, Phil's extra tweak of rebound damping in particular really noticeable when hitting high speed, high amplitude bumps. Yes, you felt it. But the dampers didn't top out, the body control remained bang on and the tyres' contact patch remained constant, even if this happened mid corner or in the midst of a cross-camber weight shift turning from one direction to the next. The kind of stuff that happens a lot on Scottish roads, or at least the ones we were on. It feels lively but controlled, if that's not too much of an oxymoron.

Jag has mastered 'smart' dampers

The fact the car does this because it's been worked on by chaps who really, really know their craft means the world too. It's this human touch that makes it all the more satisfying.

There are exceptions, Jaguar being the freshest in my mind after last week's trip to the 'ring to drive the XJ Supersports. Ringside Seat man Dale Lomas was there too and put this video up on his BridgeToGantry YouTube channel, which explains a lot more about the Jaguar approach to adaptive damping. I love the fact that the dampers 'know' when the car is unweighted over a crest and pre-empt the compression that'll follow by increasing the rebound damping according to the speed and intensity of the movement. In Jag's case this is that human touch - that expertise - being brought to bear on the available technology with hugely impressive results. But, like I say, this is the exception.

'It's as good as an SLS' shocker...

That the Roadster introduced the option of three-way switchable dampers to the SLS is an interesting aside and, perhaps, an indication of the expectations of the target audience and the marketing department. I'm glad it remains as an option though. And that Mercedes specced this press car without it, letting the real talents of the chassis engineers shine through.

Predictably (you knew it was coming...) I'm also amused that the cost of adding Ride Control dampers to an SLS is, pretty much, the same as I spent buying the Eunos and having the P5 dampers fitted. But that's a different blog and one, for now, I'll spare you!

Dan

[spiritof'76]

Pretty much agree......... step away from the buttons, Shut Up and Drive

[gck303]

Confirmation, if we needed it, that cars are designed by marketing and sales departments, rather than engineers.

[Greg 172]

I don't want to ruin it for you, but I seem to remember that it's actually Jaguar that do the whole thing with making the damper really firm to begin with and then softening it off a couple of miles later....

[HeMightBeBanned]

Lotus prove time-and-again that a passively damped car can ride and handle better than anything else the market(ing department) has to offer.

[Dan Trent]

As I say, the brand wasn't disclosed to me - my source knew who it was - but this wouldn't surprise me entirely. And would kind of make sense too, the subtleties those guys work to probably not marketing friendly in terms of giving the customer the feel he expects when he hits the sport button.

[wormburner]

I'm generally a technophobe, but completely disagree here. 5% of the time I'd like a racing car. 95% of the time I'd like a mattress.

But those two states occur during a single journey. Clever dampers go some way to optomising the car for both conditions.

[Kermit79]

Dan Trent said:

As I say, the brand wasn't disclosed to me - my source knew who it was - but this wouldn't surprise me entirely. And would kind of make sense too, the subtleties those guys work to probably not marketing friendly in terms of giving the customer the feel he expects when he hits the sport button.

This could explain why Mr Harris suffers with his Jag in the morning for the first few miles, when the damping feels like it needs to 'warm' through, and then feels much better shortly afterwards.....?

[Baryonyx]

But isn't this usually the case, that Mercedes boast superlative engineers who just 'know' what is right in a car?

[jackal]

Switchable dampers will be more relevant when we have switchable springs surely ? Chassis tuning starts with changing the springs and then altering the damping to suit. Changing single way damping settings at the same constant spring rates is fairly limited in its useage ime. Firming up dampers really hard without firming up spring rates also just feels plain wrong.

That said, i wouldnt want to be without the settings in my cayenne, im forever swtching between comfort and sport depnding on my mood and what sort of driving im doing.

Edited by jackal on Wednesday 9th May 17:43

[Palmball]

Greg 172 said:

I don't want to ruin it for you, but I seem to remember that it's actually Jaguar that do the whole thing with making the damper really firm to begin with and then softening it off a couple of miles later....

Judging from my own experience, I think this man could be right. I rarely use the dynamic setting in my XKR for the purpose of stiffening it up because it drives just fine in it's normal setting. But if I do use it, the car perceptibly stiffens up yet without thinking about it, that stiffer ride just appears to get a whole lot smoother shortly after. Mmm.....as if by magic

I've got to say though, my previous 911 Turbo with PASM had a very similar characteristic....it'd get really hard after you push the sport button followed by a much smoother ride shortly after. They both run on adaptive Bilstein dampers so maybe that explains the similar characteristics.

Also, I was recently educated on the whole 'dynamic/sport' setting by a man who knew much more about Jaguar suspension technology and set-up than me (but he never mentioned the above...thats just my perception!).

Apparently, the dampers are constantly varying between a range of, let's say, 0-100% soft-firm. In normal mode, the dampers operate throughout the whole range so can go from full soft to full hard numerous times a second. When the driver selects 'dynamic' mode, the range changes to something like 30-100% firmness. So you see, he ultimate firmness is no stiffer in the upper extreme but you lose the benefit of the comfort within the 0-30% range - this kind of proves that it really is a setting to just give the 'impression' of firmness rather than the reality of a stiffer set-up.

And in all honesty, this is how it feels hence its probably best to just let these clever electronically-controlled fluid-filled yellow tubes do the job of body control themselves....although frustratingly in my car, the dynamic button also operates the exhaust valve so it unleashes a much raspier exhaust tone which alone is worth pushing the button for

Edited by Palmball on Wednesday 9th May 17:58

[hygt2]

jackal said:

Switchable dampers will be more relevant when we have switchable springs surely ? Chassis tuning starts with changing the springs and then altering the damping to suit. Changing single way damping settings at the same constant spring rates is fairly limited in its useage ime. Firming up dampers really hard without firming up spring rates also just feels plain wrong.

That said, i wouldnt want to be without the settings in my cayenne, im forever swtching between comfort and sport depnding on my mood and what sort of driving im doing.

Edited by jackal on Wednesday 9th May 17:43

Does your car have switchable air-sprung as well as having switchable dampers? That would be great to have.

[robinessex]

Colin Chapman worked out years ago that the secret to car handling was 1. Good suspension geometery 2. Soft as possible springs. 3. Immaculate damping. His point was, that if the tyres were off the ground, er, no cornering grip !! Try a 1972 Lotus Elan Sprint on a bumpy country lane to experience.

[herebebeasties]

Much of why my Elise is so magic on B-roads is the damping. Soft springs, fast damping. Which seems to be the opposite of what most of Ze Germans seem to do, resulting in cars that are simultaneously uncomfortable and don't actually hold the road very well, other than on a track.

[ceebmoj]

As with many adaptive / computer controlled things it might not be the best right now but there is no reason why it cant be best for most people most of the time.

For example it rained hard to day and is still very damp out and about, I will probably be softening the anti roll bars a tad before driving home. It would be nice if I had a set of settings saved for a variety of conditions and could switch between them all and try different things with out getting the spanners out.

[_g_]

I haven't driven a car with fancy buttons; but for daily stuff I rather liked my poverty spec mk1 Laguna. Significantly better over speed bumps than a friend's l200.

I'd love to have the option of that kind of softness on my E36 m3, while still having it ride as it does when driving 'enthusiastically', where said Laguna was rather lacking.

[Johnboy Mac]

gck303 said:

cars are designed by marketing and sales departments, rather than engineers.

I've been saying that for several years now - the tail wagging the dog.

[untakenname]

The only experience I've had of the same model with and without adaptive dampening has been the ttrs and it was a lot better with the magneride suspension compared with standard.

[Jaged]

Right then.
"Bernie it don't make any difference, so can JB & LH have active suspension back in F1?"

"Some bloke on the internet told me so, the other won't mind!" Only joking!

I agree a decent set-up-suspension will be an improvement over the manufacturers compromise.
Ask any TVR owner who has had it done. I did.

But as already said, the ability to soften it all up, is what I think most people would prefer?
My current STR is very good, but just now and again on pot-holed roads, I'd love to just soften it up instead of having to drive faster! Sorry Officer!!

Most sports bikes these days have 3-way adjustment on dampers, as well as suspension pre-load and even height adjustment. Cars are well behind this, but do they really need it?

The best handling A + B road car I've ever driven was my year 2000 Impreza Turbo, yes the now hated Blue one with the big rear wing! Comfortable it was NOT!

[suffolk009]

Ah, yes.

MX5 - the answer to everything.

Can't understand why everyone doesn't own one. Love mine.

[V8 FOU]

robinessex said:

Colin Chapman worked out years ago that the secret to car handling was 1. Good suspension geometery 2. Soft as possible springs. 3. Immaculate damping. His point was, that if the tyres were off the ground, er, no cornering grip !! Try a 1972 Lotus Elan Sprint on a bumpy country lane to experience.

Too right.
I need some new shox for the Esprit. You can buy loads of fully adjustable aftermarket ones or the Lotus tuned Bilsteins / Eibach ones. Lotus know about handling QED. Easy choice. and the Lotus option is generally cheaper too.
Also so called "race " dampers and coilovers for the road with adjustable height/preload and damping have an infinite number of combinations. So most people have aplay for a few weeks then leave them alone / get bored etc.
Love the thought of the stiffness backing off after a while! Brilliant!