Detail is everything on the new, second-generation 997 GT3 RS. We’re heading up into the Swabian Alps in two RSs – one cosmetically perfect but mechanically non-representative, the other offering the reverse specification: a perfect set of mechanicals and a delicious patina of age that only a seriously abused test-car can possess.

You’d be right in thinking there are worse ways to spend a Tuesday afternoon. We – that’s Andreas Preuninger, project chief of all things GT3, and development engineer Jörg Juenger – pause in a lay-by to take some pictures and chat.

‘This car is a much bigger step over the base GT3 than the last RS was,’ says Preuninger, only just resisting the urge to stroke his latest creation. You don’t interview Andreas in the conventional sense, you just plonk him in front of his work and through a combination of dictaphone and notebook attempt to bottle some of his matchless enthusiasm.

The detail is, I have to say, exquisite. The front track is now 22mm wider thanks to a half-inch wider front wheel rim and new offset. The tyre is now of 245 section, and to cover the protruding rubber a plastic wheelarch extension has been added. What caught my eye was the side indicator repeater (sad, I know) which has been redesigned to fit the new shape.

I ask Preuninger ‘How much did that cost?’ His wincing, partially grinning reply ‘A few hundred thousand euros.’

It’s about the least sexy detail imaginable, but it demonstrates the level of design and financial commitment needed to produce cars of this type that meet modern legislation targets. Given the projected volumes, I still think it’s amazing that the RS doesn’t cost £250,000 instead of the £100,760 Porsche is asking.

Moving back over the bodywork, Preuninger describes the new, wider rear arches from the Carrera 4, then settles on a rear wheel: ‘The tyres are now the same width as the GT2, a 325 section. The wheel rim is the same width as before but the offset is different, so you can’t swap them with the regular GT3 wheels.’ Naturally, the centre-locking hubs remain.

This being an RS, it’s littered with weight-saving details, and that doesn’t include the fabric door-pulls, which are an appealing gimmick but nothing more. First up, the mandatory Perspex rear screen makes another appearance. A single-mass flywheel shaves 8kg from the powertrain mass (it’s 1kg lighter than that of the old RS) and there is now the grand total of zero sound-deadening, the practical side-effects of which we will discuss in a moment.

The single largest weight-saving measure is actually an optional extra – a new battery. Using Lithium-Ion technology from consumer electronics, Porsche has saved 11kg over the standard battery. It’ll be a costly extra, well over £1000, which sounds like madness, but think how much carbon you’d need to chuck at this thing to make an equivalent saving and suddenly a four-figure battery begins to make sense.

All-up, the car is only marginally lighter than a stock GT3 because the new front tyres are heavier and the RS comes with a rear cage as standard. Still, for something that casts quite a big shadow on the road and packs a 3.8-litre motor, 1370kg with fluids is a fine achievement.

Internally, the engine is identical to the regular GT3’s, but a new intake system with shorter runners, a larger plenum and one hilarious gaping-mouth of an entrance below the rear wing are said to produce a ram-air effect that helps release an extra 15bhp, lifting peak power to 444bhp.

‘We’ve gone very aggressive on the ignition timing,’ says Preuninger, ‘and with the better intake we have had to fit a revised, titanium exhaust. With the Sport button engaged and the valves open, it’s now louder than the Cup car.’

Hardly music to the ears of UK trackday goers, but Porsche acknowledges this specific problem and is working on a solution. More on that when we hear it.

I’m not especially keen on the whole passenger-ride thing, but in something like this it’s still a pretty worthwhile exercise. After all, you’re never going to use all of the performance on the public road and, more specifically, even driving it, you’re never going to answer the most important question that will be posed by potential buyers, namely: is it worth chopping my current 997 RS in for the new one?

To do that we need to explore the new mechanical grip package alongside the new aero package (170kg of rear downforce at 300kph and a vast new front splitter) and match it against the increased power that should be made even more effective through some shorter gear ratios. And that arduous task can only be undertaken at a race track, preferably the Nordschleife, with a truck full of fresh tyres (if you’re listening, Mr Porsche).

The folding carbon buckets that are an option on the base GT3 are standard fare on the RS, but the fixed-back items that weigh just 10kg including the runners are an option. They provide a better, lower driving position and are fitted to the worthy old test car.

Cabin-wise, it’s business as usual, with a few tweaks. I’m undecided on the fabric door-pulls: they’re cool but a touch disingenuous. The cupholder has been binned for a strip of carbon and the standard dash is plain plastic.
Sound dominates the on-road experience from the passenger seat. The motor fires with a thrrrrump but is almost immediately overawed by the rattle-clatter of the single-mass flywheel. Pulling away, everything is noisier: tyres, intake, exhaust – you name it, it’s louder. But not unruly. And you notice the new gear ratios, especially second and third, the way you used to in a 205 GTI through that wonderful telltale of reduced intermediate gearing – the engine note doesn’t subside quite as much as you’d expect after each upshift.

Preuninger gives it plenty on these generous, empty roads, and sure enough it feels insanely fast from the shotgun side, but how much faster than the cooking GT3 I’d be hard-pressed to say. Tellingly, and refreshingly, he doesn’t care about straight performance claims; he just knows that the RS package is far superior on-track, which is where the majority will be used. They’re expecting something like a 5sec advantage at the Ring.

What I can say for sure is that the car is still very much every-day useable. The wider rubber hasn’t brought crazy tramlining, and you can even have it with the optional sat-nav and full hi-fi.

So the differences – and much of the joy – are in the detail, but the collective effect is substantial. Now we just want to drive the damn thing.