First Drive: McLaren Senna prototype

The basics are comparable to the nearly four-times cheaper McLaren 720S... if significantly revised. The carbon fibre monocoque is uprated with a new double-walled rear crash structure – no need for a roll cage if it races, claims McLaren – and the 4.0-litre twin-turbo V8 gains 79bhp and 22lb ft, for a total of 789bhp and 590lb ft. Its suspension is hydraulically interlinked, like the 720S, but lowers in the Race mode we’re testing, like the P1 hypercar. 

Crucially, weight also drops 85kg to a lightest dry weight of 1,198kg. Everything has been scrutinised to get to that figure, but the carbon exterior panels are particularly impressive: they weigh just 60kg combined. Huge vents channel air to the uprated engine and spoilers and splitters squash the Senna into the ground with a claimed 800kg of downforce at 155mph. Put it all together and you get 0-62mph in 2.8 seconds, 0-124mph in 6.8 and lap times that are, says a McLaren insider, comparable to the slick-shod, non-road-legal McLaren P1 GTR. Wow. 

If the stats intimidate, the Senna soothes nerves on a sighting lap in dry conditions. The race seats are deeply supportive but highly comfortable, the low-set driving position is perfect, and there’s no racecar claustrophobia to this cockpit, partly due to door glass that wraps over your head and the unusual optional glass sections in the lower doors. The steering is light enough to make the Senna feel wieldy, if weighty and accurate enough to define the smallest input, gears slip by almost unnoticed, and somehow this engine feels less boosty than other McLarens, perhaps because it’s lugging less mass. It’s an easy car to drive at seven-tenths.

But the Senna is still an all-consuming experience to drive as fast as you can. Flatten the accelerator and there’s such a rush of speed accompanied by a rather industrial cacophony that you’re inclined to shift gears before the blue light ignites on the dash. But hold out for 7250rpm and the rate of acceleration as you close in on the redline is ferocious, and it makes braking as late as you dare particularly intense simply because everything is happening so quickly.

The Senna pitches forwards a little under braking to the fast right-hander at Abbey, but the weight transfer is beautifully controlled. It’s a similar story as you turn-in: there’s enough roll to convey cornering forces in a natural manner, but it’s also cushioned and controlled by the trick suspension. The fast flick left into Farm is a chance to keep on the power and really get the aero working. This is a less natural feeling, simply because it’s hard to believe how hard you can keep accelerating while lateral g-forces continue to flood over to your right, but repeated attempts increase your trust and therefore speed; you learn to overrule instinct.

The Senna also impresses in much tighter, slower corners. It’s here that the huge carbon-ceramic brakes with monobloc callipers really shine, with instant bite and stopping power like a deployed parachute. Pirelli Trofeo Rs are similarly mighty, the fronts clawing at the apex, the rears letting you get on the power early. All the while the active aerodynamics continually adapt, bleeding front downforce so the rear doesn’t squirm under hard braking, adjusting again under power. It must’ve given the engineers some serious headaches, so it’s to their credit that it feels so intuitive.

Ultimately, the Senna will push into gentle understeer on a steady throttle or sometimes rotate into oversteer – while clawing at the surface the entire time – if you’re very deep on the brakes in a tighter corner. Mostly, though, it just sticks and goes where you point it. For this reason, the Senna is arguably easier to drive quickly than a 720S, which is more of a handful. That’s not to say the Senna is less enjoyable, because this is a different kind of enjoyment – it’s the thrill of extracting every ounce of performance from a road-legal, racecar-serious machine whose excellent manners cajole you into driving at ten tenths after just a few laps. Surely Ayrton would’ve bought into that.