The Military Road that leads to the Sally Gap in Wicklow is an astounding piece of tarmac - though not by any normal measurement. I'm not the only motoring journalist in Ireland to use it regularly on which to test cars, as a drive that takes little more than an hour in total from my house and back allows me to tell you everything there is to know about a car's chassis and how it drives. It very quickly sorts the wheat from the chaff.
With that in mind I pointed the nose of the only Peugeot RCZ R in the country south and wondered if it could possibly live up to expectations that were raised by our first drive in the coupé on the brilliant Route Napoléon in France last year. That piece of road is challenging, but not quite in the same way. Those that know it well would agree with me when I suggest the world's car makers should all have chassis development centres within a stone's throw of the Gap itself.
Anyway, while cruising comfortably on the M50 it's time for a reminder of what the RCZ R is all about. Most people will focus on the engine to start with. It's of modest 1.6-litre capacity, but thanks to turbocharging - and a lot of help from Peugeot's motorsport division - it produces up to 270hp, backed up by a hefty 330Nm of torque. That latter figure is impressive enough, but the fact that it's on tap from just 1,900rpm all the way to 5,500rpm makes the RCZ R astoundingly, breathtakingly fast. What's more, there's little need to stir the (satisfyingly slick) six-speed manual gearbox to find meaningful acceleration either - it's seemingly always there for the taking. Yet, and perhaps even more impressive, the R is as docile and easy to drive as any other car in Peugeot's line-up. Admittedly the new exhaust is considerably louder than anything else with a Peugeot badge on it, but we'd argue that sports car buyers wouldn't have it any other way.
Thankfully Peugeot didn't restrict development of the R to the RCZ's engine bay. The tracks are widened front and rear, while the ride height is reduced, lowering the centre of gravity. On top of that the dampers, suspension geometry and anti-roll bars are all altered. Peugeot quotes an increase in front-end stiffness of 14 per cent and a considerable 44 per cent at the rear, where there's now a fixed spoiler for more downforce as well. The standard (and utterly gorgeous) 19-inch alloy wheels make room for much bigger brakes, which are mounted on aluminium hubs - for weight reduction and better cooling.
But I've not mentioned the best bit yet. That's the new limited slip differential, a mechanical Torsen design, which allows the RCZ R carry a lot of speed in fast cornering. It also excels on the tight and twisty confines of the Wicklow Mountains and despite the constantly changing cambers, wicked - and often invisible - bumps and myriad surface changes, it just grips and goes. Peugeot's engineers admitted that the ESP stability control system had to be reprogrammed to allow the differential work best and the result is just incredible.
Yet all this competence doesn't come at the cost of driver interaction. This is one of the first front-wheel drive cars I've driven in a long time that I'd genuinely consider alongside rear-drive sports cars. It really is that good. Sure, it's expensive, but Peugeot at least includes all the goodies for the price and it certainly feels special enough. Few cars at any level have managed this road at such pace in such an unruffled manner. And only a handful has encouraged me to turn around and do it again...