We take a prototype of McLaren’s new Ultimate Series Senna to Silverstone, and it takes our breath away.

– Silverstone, UK

When you read “McLaren Senna Validation Prototype 736,” that middle bit doesn’t sound particularly sexy or exotic. “McLaren” conjures up decades of Formula 1 teams and mind-bending road cars; “Senna” calls up images of one of Earth’s greatest ever racing drivers, probably staring off in the middle distance somewhere, looking epic. But “Validation Prototype” sounds like an electric shaver or a new recipe for protein drinks, as much as it does a near priceless early version of a supercar that someone has foolishly agreed to let me drive around Silverstone… in a light rain.

There have been moments over the last decade-plus of my car-writing career when I’ve looked around and thought, “where the fuck am I?” And after getting first packed into a set of Richard Mille-sponsored racing overalls, then five-point-harnessed into this engineering prototype of a million-dollar, carbon-fiber, land-based rocket ship, that phrase is bouncing around my skull.

McLaren Senna: First Drive
McLaren Senna: First Drive

It’s one thing to drive someone else’s supercar at the track. This is quite different: McLaren built this car as the original demonstrator of the Senna  – “It was only supposed to go round the lake” at the McLaren Technology Centre, we are told – but has been continuously refining and improving it as the final spec for the production cars has been developed.

In fact, despite its very production-car appearance, inside and out, VP736 is very much an engineering work in progress. The final version, which I’m already invited to drive in a few months, could come away with any number of tweaks to the both software and hardware. In the meantime, the folks here from McLaren would really rather I not put their precious, millions-of-pounds test car into the wall. Now that they know I can actually sit in the car, that is.

Before I so much as laced up a racing boot, multiple emails, phone calls, and surreptitious text messages were flying on my behalf. At six-foot, five-inches tall, and at a not-insubstantial 250 pounds, the logistics team was more than a little concerned that I might not fit in the car; least ways not with a full-face helmet on.

The truth is I fit closely, but happily in the narrower of the two versions of the carbon fiber racing chair, fixed to its lowest setting. My helmet is just millimeters lower than the glass panel on the top of the door, but with enough clearance for me to easily move my head from side to side, and with a great forward view of the car’s sumptuous corners. The carbon fiber seat shell here is the larger of two sizes (thank God), and McLaren folks tell me that, while you can’t adjust it on the fly, the padding can be custom fit and seat height moved to fit the eventual driver pretty perfectly. In any event, the car fits me better than the overalls do.

McLaren Senna: First Drive
McLaren Senna: First Drive
McLaren Senna: First Drive
McLaren Senna: First Drive

The car simply has all the power I can conceive of using on this fast, "international" layout of the track.

Despite the pinching, the biggest negative of the outfit is that the helmet is keeping the full opera of the Senna’s hot-rodded V8 engine from my ears. I know there are 4.0 liters of biturbocharged ferocity behind my head – good for 789 horsepower and 590 pound-feet of torque if I’m brave enough to run up to redline – but the headphones and helmet help to quiet the din. Even later in the day, when I’ve worked up to wide open throttle at the entrance to Silverstone’s Hanger Straight, the chaotic “WHAAAAA” bellow from the exhaust sounds slightly less hellacious than I know it’ll be when driven on the street.

But in a car like this I don’t need the full auditory grandeur to remind me what sort of thing I’m driving: the ability of the Senna to deliver chest-crushing acceleration and face-distorting mid-corner G-forces takes care of all of that. Zero-to-sixty times are kind of meaningless – even more so for track-focused machines – and saying that the Senna will hit that figure in 2.8 seconds is kind of beside the point. The car simply has all the power I can conceive of using on this fast, “international” layout of the track. No small part of that is due to the surfeit of power delivered to the sticky rear tires, but the truth is that the mad grip through the corners, and braking power to set them up, is even more impressive.

I have more conversations about brakes, as the test day carries on, than I’ve had at perhaps any car launch ever. The carbon ceramic material racing discs (CCM-R) may not look like the most impressive plates you’ve ever seen behind a strappy set of alloy wheels, partially because they don’t need to be as big as conventional equipment to get the job done. The 15.4-inch front discs have cooling vanes molded into their construction, and can run a remarkable 150 degrees Celsius cooler than the McLaren 720S units under heavy load, while still being 60-percent stronger. Six-piston vented monobloc calipers up front are ultra responsive on the track, though not so grabby in the initial bite that I fear for drivability on the road. And while my braking points, even at the end of the day, were pretty conservative for a car of this caliber, in the hands of the McLaren test drivers these stoppers allow the Senna to brake a massive 82 feet later at the end of Hanger Straight than is possible in the other McLaren Ultimate Series beastie, the P1.

McLaren Senna: First Drive
McLaren Senna: First Drive

Of course it only takes one look at the towering rear wing to understand that the Senna was made to give me an aero advantage around a circuit like this. And, truth be told, in most of my “feeling out” laps, only some small portion of the available 1,764 pounds of downforce was created. But before today, on the few occasions when I came charging, just right, out of Becketts and on to the straight, I’d never experienced this kind of raw adhesion in a car I was driving. Just an unerring ability to destroy a corner, in a fashion so straightforward that ittakes my glancing at the now fast-rolling speedometer to realize what I’ve done.

That kind of rush – that wave of admiration for the high limits of a machine like this – is a reward in and of itself. But to me, the part that makes the Senna a true McLaren, is that the experience is still so plugged in, and so joyful. Anything but sterile, this supercar talks to you as you drive it, offering feedback and feeling from the floor, seats, and steering wheel, even while buttoned down in full racing gear. I’d never level an adjective so blue-collar as “tossable” at a million-dollar wing car, but Senna is far more approachable than I expected, or could have hoped. This will be a car I enjoy driving on the road, at a guess, even though it’s clearly built for the circuit first.

McLaren Senna: First Drive
McLaren Senna: First Drive
McLaren Senna: First Drive
McLaren Senna: First Drive

Ungodly fast, unflappable, and yet drivable in a way that defies its brutal styling; it’s utterly true to the McLaren formula that makes me love these cars.

McLaren has never done this before: Let people outside of the company drive a validation prototype. And in the shock and awe of the power, bespoke tires, sophisticated hydraulic suspension, and the like, one much subtler element that impresses me is just how finished the car feels. Automakers are forever begging leave of “pre-production” test vehicles for poor fit and finish, squeaks and rattles and the like. But this Senna seems flawless – as though I’d pay a million bucks for it and never look back at it being a development car. Apparent build quality is hardly scientific, but it makes me feel good about the craftsmanship here, anyway.

Be it VP736 or one of the very customizable production cars that shows up around the world this summer – we expect some lively liveries from Brazilian fans – the Senna is truly special. Ungodly fast, unflappable, and yet drivable in a way that defies its brutal styling; it’s utterly true to the McLaren formula that makes me love these cars.

And I’m not done with it yet. Look for Motor1.com to have yet another go with the Senna, this time with a fully finished car, in the coming months.

Photos: McLaren

McLaren Senna

Engine Biturbocharged 4.0-Liter V8
Output 789 Horsepower / 590 Pound-Feet
Transmission 7-Speed DCT
Drive Type Rear-Wheel Drive
Speed 0-60 MPH 2.8 Seconds
Top Speed 211 MPH
Weight 2,641 Pounds (Dry)
Seating Capacity 2
Base Price $958,996

Gallery: McLaren Senna: First Drive