Feature: how to make a quick car quicker

We investigate what it took to develop the latest longtail Mclaren from the already blisteringly quick 720S

Acouple of years ago, I attended the launch of the Mclaren 675LT at Silverstone Circuit in the UK. This was the rst modern longtail Mclaren after the F1 GTR that raced at Le Mans during the nineties. Riding shotgun with the instructor short-shifting at 5 000 r/min while showing me the track, I knew the speed would embarrass most super saloons of the time. Letting the 496 kw 675LT loose moments later, the acceleration rearranged my intestines and the lateral forces caused quite a bit of neck strain.

Fast-forward a couple of years … no, I am not sitting in the driver’s seat of the new 765LT, but rather looking at a computer screen during a video call because of the pesky COVID-19 virus. Good thing, then, that I have James Warner, chief engineer at Mclaren, on the other end to explain how the 563 kw (or 765 PS, as the name suggests) 765LT was created from the “base” 530 kw 720S.

The secret lies in the clever launch-control system that can optimise torque delivery to the rear wheels – several times a second – to extract the maximum available grip between the tyres and road surface. According to Warner, the 765LT is grip-limited in the rst two gears; without electronic control, the wheels will simply break traction when the accelerator is mashed and lots of expensive Pirelli smoke will ll the air.the trick is to allow a slip percentage on the rear wheels (measured by comparing rolling speed to the undriven front wheels) to increase the tractive effort. A gure of between 4 and 10% is allowed, depending on tyre compound and surface, and care is taken not to exceed the optimal value as a steep drop-off in grip happens just after exceeding optimal value.

The acceleration figure to 100 km/h of 2,8 seconds is remarkable for an RWD vehicle