McLaren 720S GT3X: what is it and why should I care?

If you don’t know by now, McLaren’s bonkers 720S GT3X lapped Dunsfold in 1min 07.2secs at Top Gear’s Speed Week 2021. And yes, that is seriously quick. Watch it (and our full review) by clicking these lovely blue words.

But what actually is the GT3X, and why should you care about it? Simple questions they may be, but McLaren’s range of supercars and racecars isn’t exactly the easiest to wrap your head around. Hope this helps…

As you might be able to tell, the GT3X is not road-legal. Far from it, in fact. However, it also won’t be eligible for any race series – that’s because McLaren’s race team builds the GT3X without any regulations holding the (very brainy) engineers back. It only shares 10 per cent of its components with a 720S road car, but also only 50 per cent with the 720S GT3 car.

Is that a sarcastic dig at McLaren we're sensing? Anyway, yes it does use a version of the road car’s ubiquitous M840T 4.0-litre twin-turbo V8, but here there are stronger pistons and a lightweight exhaust system. It makes the same 710bhp (720PS) as the road car, but a push-to-pass button on the steering wheel unlocks an extra 30bhp for straight lines.

Incidentally, the 720S GT3 racer uses a (secret) V8 from elsewhere in the McLaren lineup as it’s restricted to somewhere around 500/550bhp. 
 

The GT3X only weighs 1,205kg and gets no added racecar ballast, so yeah, it’s fast. Mega Alcon brakes mean it stops pretty rapidly too, though. Click here to see how the GT3X’s Dunsfold lap time compares to its rivals. And by rivals we mean a Ferrari FXX-K, a Le Mans-prepped Aston Martin DBR9 and Renault’s R24 F1 car. Blimey. 

Again, the answer is very. The body panels are all carbon fibre and the aero kit is largely similar to the one on the GT3 car. The massive swan neck rear wing is exactly what you’d find on the racer and looks as though someone bolted on an RSJ that was lying around the factory. Still – we’d suggest it’s easier on the eye than the Senna GTR.

It’s a bargain at £750,000, and McLaren hasn’t actually said that it’ll limit the number it builds. How about buying ten to create your own one-make race series? Count us in…

If you’re thinking about it, you’ve probably already got access to your own/a mate’s race track and you probably already own a P1 GTR and a Senna GTR. Both of those were built by McLaren’s road car department though, whereas the GT3X is a full motorsport project. It’s down on power, but would apparently beat both around most circuits in the world. Worth adding to the collection just for that, isn’t it?