McLaren 720S GT3X: The Track Weapon With No Rules

Introduction

The McLaren 720S GT3X is not your ordinary racing car. In fact, it is not a racing car at all, and it can never be driven on the road. Instead, it is an experiment into the possible: a car that costs 720 grand, produces 740bhp, weighs just 1,210 kilograms, and of which only 15 examples will ever be built.

Think of the GT3X as the ultimate version of what a GT3 racing car could be if there were no rules. Driven recently around the fearsome Navarra circuit in northern Spain, it proved just how far McLaren has pushed the boundaries.

What the 720S GT3X Actually Is

This is a seriously rare piece of kit. The concept is simple: take everything that makes a GT3 race car quick, remove the rulebook restrictions, and see what happens. The result is a car that generates astonishing confidence at speed.

You could feel the aero in any corner above about 80 mph, and it invites trail braking right into the heart of each corner. It also carries multi-stage traction control; even on a friendly-ish setting, an overly ambitious throttle application mid-corner can still rotate the car, but it feels remarkably approachable overall.

Phenomenally quick, yes, but honestly anyone who roughly knows what they are doing would not be too terrified by this car.

Braking and Handling Impressions

The braking performance is one of the defining characteristics. It takes a while to understand just how little room you need to stop from such huge speeds, and the way it hauls itself down into a corner can only be described as rude.

It rides the curbs beautifully too, a small but telling detail that shows how well sorted the chassis is on a demanding track like Navarra.

Engine, Gearbox and Chassis Details

The engine is very similar to the unit in a GT3 race car, except the GT3X has no restrictor to breathe through. That is how McLaren unlocked so much more power and torque: about 720bhp in normal mode, rising to 740bhp with the push-to-pass system engaged. A GT3 racer, by comparison, makes less than 600 horsepower because of its restrictor.

The gearbox is a six-speed sequential unit, while the differential is mechanical but electronically adjustable, both engineered by Xtrac. Traction control and ABS are adjustable on the move, as is the brake bias, although the discs themselves are steel rather than carbon.

At each corner sits a fat but not especially tall 18-inch Pirelli racing slick. The aerodynamics are broadly in line with those of the GT3 racer, but with more liberal use of carbon fiber, and McLaren says absolute downforce sits around the 1,000 kilogram mark.

Worth the Price Over a GT3 Race Car?

Here is the awkward question. Because of the GT3 racer’s restrictor, the GT3X puts a rather big question mark next to its own value: the GT3 race car costs roughly a quarter of a million pounds less. That said, there are many other differences between the two, predominantly in the aero, where the GT3X enjoys fewer constraints and more carbon.

A cynic might say the GT3X is nothing more than a racing car that will never race, a car without purpose. In truth, it is a whole lot more than that. It serves as a mobile test bed for all sorts of good stuff that McLaren’s road cars will benefit from in the future, and even in the here and now it is a mighty piece of kit, both to drive and simply to get excited about.

Conclusion

The McLaren 720S GT3X is an extraordinary expression of what a track car becomes when regulations fall away: 740bhp, 1,210 kilograms, 1,000 kilograms of downforce, and only 15 examples in existence. It is not for the road, and it is not for the grid, but as an experiment into the possible, it is a mighty piece of kit.