493bhp GT3 RS represents a new level for the 911 - faint hearts need not apply The purest realisation of what Porsche estimates a sports car to be. The new 911 GT3 RS is not a car made faster by the addition of turbos or hybrid drives, but through the deletion of weight and provision of more power via the delightfully back-to-basics formula of shoveling a bigger engine in the boot.So today’s GT3 RS displaces precisely the same 3996cc and produces an identical 493bhp at an indistinguishable 8250rpm as the last 997-based GT3 RS, despite their engines being entirely unrelated. The difference is that while the 4.0-litre 997 GT3 RS was a limited-edition special, this 991-derived machine is part of the standard model line-up. No 911 has ever been fitted with a bigger engine.The extra capacity has been achieved by fitting a longer-throw crankshaft to increase the stroke, so while there is no change to the speed at which peak power is delivered, peak revs have been pegged back a couple of hundred rpm, meaning its poor owners will have to content themselves with a sluggish 8800rpm limit. The flipside is a small increase in torque and a flatter curve, albeit still peaking at the same 6250rpm.The transmission is the same two-pedal PDK dual-clutch automatic unit used in the GT3 but with its final drive shortened slightly to counteract the effect of taller rear tyres. The paddles themselves have a shorter, sharper action.Porsche’s plan for this RS was to create more fresh air between it and the GT3 upon which it is based than has been the case with any other in the dozen years and five generations since Porsche exhumed its most revered acronym and once more applied it to a 911. So alongside all the usual RS modifications, such as a wider front track, Perspex rear screen and rear quarter lights, this RS has been enhanced in many other ways, of which the larger engine is just one.Most telling is the decision to base the RS on the ultra-wide body of the 911 Turbo, making it 28mm wider at the back than the current GT3. But there is also a magnesium roof and carbonfibre front wings to go with its carbonfibre bonnet and bootlid. The result is a car 10kg lighter than the GT3 - a fairly astonishing achievement when you consider the extra weight of the Turbo body and its larger 20in front and 21in rear wheels.As you might imagine, extensive attention has also been foisted on the chassis, where you’ll find different anti-roll bars front and rear, a completely new damper iteration and stiffer rear springs to cope with the vast increase in rear downforce. Interestingly, the front springs are carried over from the GT3, the slight increase in ride height due to the larger wheels which meant a stiffer spring was not required.The Michelin Cup tyres (and optional Dunlops) are a bespoke development for the car, too, but required far less work than expected, largely because they started life on the 918 Spyder.The traction requirements of a rear-drive, rear-engined car relative to a four-wheel-drive, mid-engined car brought changes in compound and construction but nothing dramatic. By contrast, Porsche needed to start again with the electric power steering in order to adapt it to the rigours of the additional downforce and an increase in front-end grip so great it is estimated to increase turn-in speed by up to 20%.But talk to those who did the development work and they will tell you that the seven-league difference between this RS and the standard GT3, not to mention any other road-legal 911 in history, is the aero.For years all 911s emanating from the Motorsports department have offered not merely reduced lift, but genuine downforce. The GT3 RS, however, is a world apart, its new front spoiler generating 110kg of downforce all by itself, while the massive rear wing creates a further 220kg. In total it has triple the downforce of the GT3 or, put another way, more downforce at 124mph than the last GT3 RS could muster at 186mph. Put a third and final way, here is a standard production road car offering 80% of the downforce of the Porsche’s GT3 Cup car.It adds up to a car capable of reaching 62mph in 3.3sec (clipping 0.2sec off the GT3’s time) but topping out at 193mph - 2mph short of the less-powerful GT3 thanks entirely to the additional drag of its aero package.And yes, there is a Nürburgring lap time: 7min 20sec, just two seconds shy of the time managed by the 611bhp GT2 RS, the most powerful street 911 ever built. But in fact the GT3 RS's lap was set on a cold, damp track. Porsche’s own simulations show the car to be capable of a 7min 17sec lap in ideal conditions, which would make it the fastest road-going 911 ever to take to the track.from Autocar RSS Feed http://ift.tt/1Kx2yhS
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