Eau Rouge, that winding sliver of tarmac carved into the Ardennes forest, is its USP. It's not just one corner, it's a complex of three. A jinking left-hander buried in a treacherous dip unsettles the car and sends it bouncing into the right-hander that is sharper than you'd ever think and requires an early apex. The exit into the left-hander at the top is totally blind, a leap of faith, and the car pops out of the Radillion corner over the crest while the momentum tries to rip the dampers from the car. The gradient is the most impressive thing, and television cannot relay the experience as the straight plunges downhill before the corner takes off like a ski-jump. When stoned surfers rattle on about 30-ft breakers they've never actually seen, this is the driving equivalent.
In racing it's vital, as it leads onto the long, uphill Kemmel Straight, where Formula One cars fly through at 180 mph-faster in qualifying trim. I was in a highway cruiser that could carry five people across a continent in comfort on leather seats, with music wafting through the sophisticated speaker system and rain-sensitive window wipers, and I could still do 110 mph on the way in. The clocks weren't on us, though. A track day is all about personal limits, coming into each bend a touch faster every lap, hitting the apex and feeling the tires squirming. It's all about personal limits was the obvious conclusion from watching some of the straightline superheroes hammering the throttle on the straights before slowing to grandmother speeds for corners. Being forced to brake mid-corner to avoid compacting a Westfield was a shock, but the talent was as varied as the machinery and some were more than useful.
As for the Jag, it should have been as out of its depth as a bleeding swimmer dropped into a shark-infested ocean, and on occasion it was. But the four-wheel-drive system designed to keep leadfoot junior execs out of trouble in the rain proved a big surprise. Under acceleration the 231-bhp, 24-valve machine revved freely to its 6800-rpm limit and even left sluggishly driven Porsches behind out of the hairpins due to a 0-to-60 mph time of 6.6 sec. From 110 mph up to its 146-mph top speed, a saint's patience would wear thin, but that is beyond the remit of most road cars.
And while others battled with skittish Caterhams in the twisty bits, if the Jaguar turned in at all, it would come out pointing the right way. Even at Pouhon, which is much underrated as a mind-shattering, scary corner. This double-apex left-hander has just about every obstacle going. It's downhill, off-camber, blind and bloody fast. It's a testicular test that's all about final exit speed, but it invites you to grab the first apex too early and run out of road. I did this once, hearing the crunch of my right rear tasting gravel and the "pooshp" of my heart slamming against my ribs. True to form, the Jag pulled out of the danger area, however, to the echo of my infinite thanks.