A handful of laps on Millbrook’s demanding hill circuit reveals the Q50 Eau Rouge is already far more than just a mere collection of ideas thrown at a concept whose primary role is to look good on a motor show stand.
Instead it transpires to be a fully functioning prototype that has been engineered to a level of maturity that makes it sufficiently advanced to be considered for production.
From the outset, it is the engine that steals the show. Serving up 224bhp and 173lb ft more than the standard Q50 S’s turbocharged 3.7-litre V6, the returned GT-R powerplant endows the Q50 Eau Rouge with truly serious pace – the sort that should see the production version closely challenge rivals a straight line tussle.
Infiniti’s in-house performance targets pitch the Q50 Eau Rogue well into the sharp end of the performance saloon ranks, with a 0-62mph time of “less than 4.0 seconds” and a top speed “pegged at 180mph”.
With a four-wheel-drive system providing impressive levels of traction off the line, it launches with great bravado and delivers huge on-boost in-gear shove on a planted throttle.
With a kerb weight of 1825kg, the one and only prototype in existence right now is still above Infiniti’s target weight of 1800kg, partly due to it retaining a steel roof and glass sun-roof – which are planned to be replaced on the production version by a carbonfibre structure.
It is not quite as quick nor anywhere near as aggressive in character as the GT-R, but that’s not Infiniti’s aim. What it is seeking is a more refined driving experience in line with a more mature customer base.
Inevitably, though, there are areas that require further fettling before you could describe it has being fully fit for the showroom.
Throttle response is tardy at the lower end of the rev range. Given the level of turbocharger boost pressure this is no real surprise.
Although Infiniti argues it is more to do with the fact that it has been forced to reduce the torque loading of the engine to suit the gearbox, which is limited to no more than 442lb. “We’re looking at alternative gearboxes that can handle more torque,” says Snowball, suggesting Infiniti’s close engineering ties with Mercedes-Benz may provide an answer.
If the Q50 Eau Rouge’s ability to tolerate being flung around Millbrook’s most demanding piece of bitumen at high speed without surrendering its authority is any guide, the chassis tuning of what is shaping up as its future performance flagship is already heading in the right direction.
The steering, which has reverted back to an electro-mechanical system after initially sporting the fully electric arrangement used on the Q50 Hybrid, is encouragingly direct, conspicuously quick and nicely weighted. There are enthusiastic turn-in traits and with quite a bit of initial front-end bite it manages to carry an impressive amount of speed up to the apex.
Infiniti has tuned the Q50 Eau Rouge’s four-wheel-drive system to provide a nominal 50:50 drive split front to rear in a move aimed at achieving neutral handling characteristics. In high-speed corners it is very impressive.
Taut damping and anti roll bars measuring 32mm up front and 20mm at the rear helps provides great body control, and there is plenty of purchase from those sticky Pirellis once you’re committed.
In tight corners, though, and the sheer potency of the drive forces being deployed by the front wheels eventually overcomes the purchase delivered by its grippy tyres on a loaded throttle, leading to a touch of understeer and the intervention of stability control when you push hard at the exit. Still, given the customer base Infiniti intends to pitch the car to, it is probably the right way to go.
Development work is already underway to determine whether the car may benefit from a slightly more rearward bias of drive, or perhaps more advanced mapping to speed up the apportioning of drive between the front and rear axles as grip levels vary, although a final decision is yet to be made.
Ray Mallock Limited is yet to fully sort the finer points of the springing and bushing, although an earlier test session by Sebastian Vettel was aimed at providing feedback on the overall set-up.
The Q50 Eau Rouge prototype didn’t much like low frequency bumps and the front end is particularly sensitive to changing surfaces, but these should be ironed or at least minimised out by the time it reaches production.