Infiniti Q50 Eau Rouge Prototype 2014 Review - International

This is beginning to feel more than a little surreal. I’m sat behind the wheel of the Infiniti Q50 Eau Rouge prototype – the only example in existence – and I’ve just been told by the company execs that I can have my way with the car for the next two hours. In fact, I’ve actually been encouraged to wring its neck.

Normally the drill with prototypes (especially one-offs!) is that you get to trundle around a boring stretch of road at dawdling speeds, usually with a minder in the passenger seat to rein you in the moment you begin to even begin to entertain thoughts of pressing on a little.

But today it’s open slather, and my playground for the next couple of hours is the dipping, diving Millbrook Hill Route in Bedfordshire in the UK. It’s a supremely technical and challenging strip of tarmac with an assortment of blind crests, off-camber corners and a variety of road surfaces adding to the degree of difficulty.

There’s also a nice ‘yump’ towards the end of the circuit where you can catch a bit of air if you’re brave enough. Just to make it even more interesting, there’s no run off on most corners -- just guardrails and foliage.

If you make a mistake here, chances are it won’t be pretty.

I’ve just been taken around the snaking ribbon of tarmac for a couple of 'recce' laps by one of the Millbrook staffers, and then I’m left to my own with the matte red prototype.

Before we move on, some background on the Q50 Eau Rouge…

The name? The hottest Infiniti yet gets its evocative suffix from the ultra-fast left-right-left kink at the Spa Francorchamps circuit in Belgium. Taken flat out in a Formula One car at around 320km/h, this rapid rollercoaster kinks left, compressing the car’s suspension (and the driver’s body) at its base, then twists right as it fires steeply uphill before coiling left again to a blind crest that demands perfect car placement and significant bravery to take flat out.

It’s an appropriate sobriquet for this particular Q50, because stuffed beneath its aero-enhanced snout is a 3.8-litre twin-turbo V6 sourced from Nissan’s GT-R halo car.

It’s been recalibrated via a Motec ECU to provide a more refined power delivery befitting an Ininiti, but it still belts out a substantial 418kW and 600Nm, which puts it in the same ballpark as the BMW M5 and Mercedes E63 AMG.

To ensure the car can wipe off massive speeds as quickly as it can rack them up, it packs the same massive Brembo stoppers as the GT-R, with 390mm discs at the front and 380mm anchors at the rear.

Further mirroring the GT-R, the prototype sedan sends drive to all four wheels (50:50 front and rear) but it foregoes the rear-mounted six-speed dual-clutch gearbox of the former as it would have meant ditching the Q50’s back seat and relocating the fuel tank. Instead, the Eau Rouge uses a seven-speed auto borrowed from the V8-powered Q70.

The engineering work for the Eau Rouge is the handiwork of UK-based motorsport engineering firm RML – the same mob who produced the bonkers Nissan Juke R that we sampled at the Dubai Autodrome a couple of years ago.

What’s particularly impressive is that the Eau Rouge was fast-tracked from concept to working prototype stage in just four months but, as I’m about to find out, the car feels surprisingly well sorted considering its ultra-brief gestation period.

For the time being, this project is purely for evaluation, as the Infiniti top brass needs to first work out if the business case exists for a circa-$200,000 model in its line-up, even if the vehicle in question would be capable of serving up BMW M5-matching performance and dynamics.

Secondly, they’ll need to sort out production logistics for the Eau Rouge and subject it to the necessary durability and hot-weather testing if it’s to be a mass-market offering.

Shoehorning the GT-R’s V6 with its twin turbos, intercooler, twin oil coolers and heavy-duty radiator in the Q50 was a challenging task and the boffins’ initial thoughts were that the car’s front overhang would need to be stretched, but RML somehow found a way to make it all fit without any dimensional increases.

That said, almost every exterior panel is unique to the Eau Rouge, with only the front doors and roof carrying over from the standard car. New front and rear fenders broaden the Q50’s stance by 20mm, and there’s a carbon-fibre front spoiler/splitter that minimises lift and sends sufficient cooling to the brakes and engine.

In addition there are NACA ducts in the bonnet, carbon-fibre side skirts, a larger rear lip spoiler and bespoke rear diffuser with a central brake light from the Red Bull RB9 Formula One car.

Protruding through the diffuser is a huge pair of tailpipes to dispense spent gases from the twin-turbo V6. Infiniti and RML are also evaluating the possibility of a carbonfibre roof panel, which they say is doable.

The Eau Rouge sits 20mm lower than the standard Q50 via bespoke springs and three-way adjustable dampers, and it also scores beefed-up front and rear anti-roll bars and a tasty set of 20-inch forged alloys shod with 255/35ZR20 Pirelli P-Zero Corsas.

It’s an intriguing recipe, but what I’m here to find out is whether it all comes together as a cohesive package, or whether the Eau Rouge feels like some other half-baked prototypes I’ve driven over the years.

BEHIND THE WHEEL
First impression is how deceptively ‘normal’ the car appears from the inside. Aside from the excellent leather/suede Recaro sports seats, the cabin provides no obvious giveaways to the car’s hugely enhanced performance capabilities.

The impression of normalcy doesn’t change even after rousing the twin-turbo V6 into life, as it sounds remarkably docile and ticks over unobtrusively.

I’m told to work the auto transmission manually rather than rely on it to upshift and downshift on its own as the appropriate shift points haven’t been calibrated for this car.

The most noticeable change becomes apparent as soon as I pull away from standstill and discover it takes a huge effort to wind on any steering lock.

The reason for this is that the steer-by-wire system of the standard Q50 has been binned in favour of a conventional electrically assisted set-up, but since it’s not been calibrated for this car, the steering is massively weighty at parking speeds.

No matter though, because it feels great when you’re punting the Eau Rouge at its limits – and this is much more than can be said for the standard Q50’s steer-by-wire system, which feels unnatural as soon as you start pressing on a bit.

Upping the pace once I’ve figured out the basic layout of the Millbrook Hill Route, a few things become immediately evident. Firstly, the bespoke springs, dampers and anti-roll bars have seemingly worked a miracle, because the Eau Rouge barely shows any hint of body roll, even when I’m absolutely hurling it at corners. Secondly, the 20-inch Pirellis cling to the tarmac with bulldog-like tenacity, even through some of the Hill Route’s off-camber bends.

RML development engineer Tom Snowball says the car tips the scales at 1826kg, but my seat-of-the-pants impression is that the prototype feels at least a couple of hundred kilos lighter.

Another eye-opener is how effectively the car converts its 418kW and 600Nm to forward motion. Sure, the two hairpin corners on the Hill Route require throttle modulation to prevent the Eau Rouge from pushing its nose straight on, but I find I can stand on the gas much earlier than anticipated through the other bends.

What’s more, the GT-R-powered sedan makes mincemeat of any straights, as reflected by an estimated sub-4sec 0-100km/h sprint and 300km/h top whack.

But while the engine and chassis dynamics appear pretty well sorted, there’s still work to do on the car, and much of this needs to be focused on the transmission. To ensure the prototype’s seven-speed auto doesn’t end up an expensive pile of scrap metal (given the engine’s massive power and torque outputs), RML’s engineers have slightly retarded its shift speed to lessen driveline shock.

This means the transmission doesn’t have the whip-crack immediacy of, say, the excellent M-DCT gearbox that comes in the M5.

Indeed, not only are upshifts slightly tardy, the transmission occasionally seems reluctant to respond to commands issued via the steering-wheel paddles. However, the transmission in its current state is only a stop-gap arrangement and it will be finessed if the car gets the production green light.

The same goes for the exhaust system, which doesn’t deliver the fruity note one might expect of a high-performance sedan. It doesn’t sound too bad, but it’s a tad characterless compared to an M5… and plain uninspiring versus the thunderous Mercedes E63 AMG.

An interesting fun fact about the Eau Rouge’s exhausts is that they expand appreciably when they’re hot, to the extent that they were protruding about an inch beyond the rear bumper when I brought the car in after an extended session of hot-lappery. But all it took was one cool-down lap for them to again shrink to normal size and sit flush with the rear bumper.

Other areas that will need to be addressed if the car is to be developed further is the aforementioned steering system and there’s also a bit more bump-thump and driveline noise than ideal, but that’s only to be expected in a largely hand-built prototype.

These shortcomings apart, the Q50 Eau Rouge prototype stacks up as a far more impressive device than I had expected, particularly as Infiniti and RML have retained the basic architecture of the standard car.

Apart from being stunningly quick around the Milbrook Hill Route (I reckon it would at least match an M5 or E63 AMG around this snaking ribbon of road), the Eau Rouge also rides with an agreeable level of compliancy, doesn’t overheat even after sustained caning and its five-seat capacity and large boot are, of course, unchanged from the donor car.

If you were to evaluate its raw deliverables, the Q50 Eau Rouge appears to have great potential.

However, even if the go-faster Q50 were to get the green light, it would take another 14-18 months to develop the car to production-ready stage, according to Infiniti global communications manager Stefan Weinmann.

Will it retain the ‘Eau Rouge’ suffix in production form? Yet to be decided, says Weinmann.

The petrolhead in me would love to see Infiniti build and sell this car at a sub-$200k price, but in order for this to happen, the company’s top brass needs to be convinced there’s a profit to be made by doing so, and also that the vehicle would provide the desired halo effect for the other models in the brand’s line-up.

Given that the Q50 and Q70 are competent yet by no means exceptional cars, plus the fact that the Infiniti marque currently lacks the aspirational status of the German luxo brands, I reckon there’s only one correct course of action here.

Go ahead and hit that green light, Infiniti. It’s time the Teutonic brigade didn’t have it all its own way in the super-sedan arena.