Nissan Skyline GT-R Z-Tune

Under the bonnet, the reconstruction is so comprehensive that you can see why the rest of the car has needed overhauling in a process that sees each model reduced to a bare shell. The standard V-spec GT-R straight-six produces 276bhp, but this version yields a startling 493bhp. And that’s an ‘at least’, apparently.

You’re not short-changed on pulling power either, the peak torque running to 398lb ft. Nismo’s engineers have delved deep into the engine to wring out this extra power. At its heart are reworked combustion chambers. There are re-profiled cams, a beefed-up block and a forged and fillet-rolled crankshaft which has been finely balanced, as are the upgraded, forged pistons. There’s a baffle plate in the sump to counter oil surge, and the whole ensemble is crowned with a Z-Tune rocker cover.

It doesn’t end here, either. There’s a specially built IHI turbocharger, a remodelled intake plenum and a revised exhaust manifold. Meanwhile, twin oil coolers, an upgraded radiator and intercooler, high-flow fuel injectors with a more potent injection pump are also provided. And finally, there’s a Z-Tune electronic control unit.

Elsewhere, there are three-way adjustable dampers that can also be altered for ride height, reinforced front strut towers, 18in alloys in a sinister black, a twinplate clutch and upgraded brakes that include six-pot calipers up front and four at the rear. The bodywork has also been resculpted purposefully.

Oddest are the air extractors in the trailing edges of the front wings just ahead of the door mirrors which leave you in no doubt about the car’s intent. And that’s rammed home with aggressive new bumpers and an adjustable rear wing, all of these in carbonfibre, as is the bonnet. Oh, and the Z-Tune package includes new front seats, restyled door trims and a 200mph speedo.

Actual performance claims are limited – Nismo quotes over 155mph, but surely 180mph must be possible? The firm also claims the car has a 0-400m sprint time of 10.06sec compared to 12.8sec for a 911 GT3. It’s damn quick.

Why Z-Tune? This is Nismo’s ultimate performance package, offering maximum potential and producing a well-rounded car. The less extreme R-Tune set-ups are for drivers with race experience, the entry-level S-Tune for enhanced street performance. But never mind the lesser upgrades – we’re about to try a Skyline with maximum firepower, a car developed to create what Nismo believes is ‘the strongest road-going car in the world’.

Now that’s a description impressive for its complete failure to hint at how brisk this machine is. Instead, the car itself provides the right signals through its pipeline-long exhaust, snarling front and rear wing worthy of a light plane. And once you’re belted into those fat, bolstered seats your body won’t be travelling anywhere but with the missile to which it’s strapped.

So it’s good news that the car doesn’t behave as rampantly as it looks. You need a bit of precision to control the competition clutch, and a firm hand on the gearlever, too, but otherwise, this bull of a car is as docile as a new-born calf. In fact, the power delivery almost feels a little slack. But dealing with this engine is like eating a red hot chilli pepper – the potency builds, and once it’s there the sting doesn’t drop off.

This is not something you find out straight away. You need to have that toughened crank pumping beyond 3000rpm, and sinking the throttle on a third-gear bend with the wipers thrashing at a monsoon doesn’t seem like a good strategy for guaranteeing safe passage. Instead, you find yourself easing your way into this GT-R. Well, you do at first. Trouble is, after a few bends taken at moderate pace, you begin to suspect that this car’s chassis has a dictator’s iron grip, which encourages a bolder right foot.

And the wheel – well, it reminds you what a confidence-booster truly feel-some steering can be. The rim jigs gently as the front tyres ride gentle swells of asphalt, resistance builds smoothly as the Nissan sears unerringly through curves, while the seat-to-bum messaging service has you believing that this car’s intentions are as easy to read as motorway road signs. Which is probably a mistake, because the compensating activities of the yaw-sensing, four-wheel steer, four-wheel drive can have the GT-R reacting in unexpected and unsettling ways when pushing the car hard, as it compensates for heart-stopping errors.

What’s also a surprise is the speed this Skyline can carry into corners, the traction it musters out of them, and the discovery that you can ride this torrent of momentum in a never-ending gush of power.

Of course, you have to ease off for tight bends, heel-and-toe your way to lower gears and drive in the knowledge that you might have to slow for the unexpected, but so forceful is the Nissan’s punch, so fluent its mastery of curves, that you don’t want roads to end. But even in these rainy conditions, I realise I’m unlikely to discover the outer limits of the Nissan’s grip.