I'm slightly obsessed with vehicle dynamics at the moment.
The other day I learned that the latest Porsche 911 GT3 has magneto-rheological engine mounts. They're a simple enough idea, but one that's probably a right royal pain in the backside to tune properly. The theory is that they're slack when one wants to dampen noise and vibration (say during stop/start or unhurried gearchanges), yet they're stiffened at the right times so the engine's mass doesn't affect body movements (during hard cornering, acceleration or braking, for example).
Evora is UK's Best Driver's car - full storyMega sideways picture galleryWatch the action on videoI've been thinking a bit more about this recently, after a conversation with Matt Becker, Lotus's engineer in charge of the way the Evora drives.
We'd chatted over a pint about a particular car that's happy to be oversteered, but looks and feels a bit clumsy on the way out of a slide. Becker's theory was that the engine was moving in a direction that unsettled the car just at the wrong time.
My understanding is that having been squashed onto its mounts via the lateral g of a corner, the engine was effectively bounced back in the opposite direction as the cornering force lessened, sending a couple of hundred kilos of engine back across the bay – not very far, but enough to unsettle the car's balance. Like having a bad pillion on a motorbike.
“Engine mounts are something we spend quite a lot of time tuning,” admitted Becker. And when you start flinging the Evora around a track, as Autocar did during our Britain's Best Driver's Car feature a few days later, you can feel it.
The Evora's mounts are passive but tuned so finely that you never feel the engine's weight transfer when pushing the car hard. The Evora can be coaxed into and out of its limits of grip incredibly easily. And, for a mid-engined car, it's astonishingly forgiving.
According to Becker's colleague Gavan Kershaw, it makes drivers who, let's say, aren't quite all that - ones who wouldn't dare get an Exige sideways - look surprisingly handy all of a sudden.
There's more to the Evora's benign nature than just the engine mounts , of course. Its steering is nigh-on perfect for an assisted system (hydraulic assistance, and not much of it because of the car's light front end). Its ride is more compliant than one might expect, and there's enough roll so that you know you're pushing the car, but the rate of roll is mellow and it finds its levels gently.
Really, the Evora's brilliance is down to hour upon hour of fine tuning and, crucially, having one bloke in charge who understands all the individual components and is free from petty big-company politics. Not a damper engineer, a tyre engineer, a spring engineer and a steering engineer working with wheel and tyre sizes dictated by the marketing department.
That's why I find it such a fascinating subject. That's how companies still get it so wrong despite having done, possibly only weeks earlier, something so right. That's why Lotus gets called in to sort out, tweak, tune, hone, or just develop other manufacturer's chassis.
And that's why the Evora will be a handling benchmark for years to come.
