Just how fast is the McLaren Senna?

We already knew that this simpler, rear-drive, non-hybrid hypercar would beat the P1 hands down for weight – at a (dry) 1198kg it’s four large men lighter than its predecessor – and as expected its accelerative abilities reflect that. We don’t know its kerb weight yet but whatever it is, this is bound to be the lightest McLaren road car since the F1.

There’s another weight figure just as crucial, one we didn’t know until now and which promises to define the Senna driving experience far more than standing start times. Who, after all, wants to go in straight lines all the time?

The figure we didn’t know is 800kg – the average weight of a cow – that presses down on the car when it is travelling at 155mph. This level of downforce is thanks to what McLaren calls an uncompromisingly form-follows-function design, one that according to chief designer Rob Melville is at a whole different level even from the P1. 

With aero blades, a multitude of intakes and vents, gurney flaps, splitter, diffuser, stepped louvres and that giant carbon-fibre rear wing the Senna is an aerodynamicist’s parts bin brought to life. That rear wing incidentally weighs just 4.87kg, yet can support more than 100 times its own weight in downforce.

Along with its active suspension, it’s this downforce and consequent trackability that promise to put clear blue water between the Senna and the P1, and make it McLaren’s quickest road-legal track car yet. With a power/weight ratio of 659bhp/tonne and that trick aero, it should be more than a match even for the P1 GTR (685bhp per tonne).

As McLaren puts it: “The true depth of the performance credentials of the new Ultimate Series McLaren will be revealed when it calls on its downforce on a circuit, against the stop-watch.”

The new gallery of pictures revealed today, showing the car in a less aggressive colour than originally, confirm just how form-follows-function the Senna is, and the elements of racing DNA that show up. It will need all of that and more in coming months as it takes on other imminent new racing-cars-for-the-road like the Adrian Newey-designed Aston Martin Valkyrie and F1-engined Mercedes-AMG Project One.

For now, enjoy the pictures and savour the numbers…

McLaren Senna numbers countdown

£2,000,000 - winning bid of a Senna auctioned in December to raise money for the Ayrton Senna Institute helping underprivileged children in Brazil

£750,000 price tag of the 500 cars

1198kg lightest dry weight

800kg of downforce at 155mph

789bhp at 7250rpm, the 4.0-litre biturbo V8 is McLaren’s most powerful pure combustion road car engine

659bhp per tonne power/weight ratio

590 lb ft of torque at 5500rpm

500 to be made, and all allotted

300 hours to hand-assemble each car

211mph top speed

180mm (7ins) lower rear deck than 720S

60kg - weight of carbon-fibre body panels

9.9 seconds, standing quarter mile (400m)

7.32kg, weight of special Bowers & Wilkins sound system (echoes of the F1’s lightweight Kenwood stereo!)

6.8 seconds, 0-124mph

2.8 seconds, 0-62mph