Thursday 10th May 2012


PH BLOG: PASSIVE / AGGRESSIVE

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


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
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
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
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...
'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

Author: Dan Trent
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