"Longtail" returns – meet the hardcore McLaren 600 LT

Revealed today for the first time ahead of its dynamic debut at the Goodwood Festival of Speed presented by Mastercard, the new 600LT is only the third "LT" after the F1 GTR Longtail of 1995 and the 675LT of 2015. Like those cars, the new road-legal track car gets the expected LT trinity: more power, less weight and optimised aero. Not forgetting a longer tail of course. That’s 74mm (3in) up thanks to new carbon-fibre bodywork and an extended diffuser and big fixed rear wing.

The 600LT is a Sports Series model – ostensibly the brand’s junior range – but there’s little that’s entry-level about its spec. The familiar 3.8-litre twin turbo V8 has been upped to 600hp (that’s 592bhp), while torque is up a little at 620Nm (457 lb ft). The V8 gets a new cooling system and new exhaust with less back pressure and what McLaren is promising is a new stimulating new sound.

There’s a reason for that: the twin pipes are super-short and exit upwards out of the rear deck, just behind the driver’s shoulder. It’s a more extreme set-up than the Senna has, says McLaren, and there’s no doubt it looks cool; visually it’s sure to become this model’s aesthetic calling card. The new exhaust also saves a lot of weight.

In its most extreme (optioned-up) lightweight form the 600LT tips the scales (dry) at 1,247kg, saving 96kg over a comparable 570S coupe. That amount of mass results in an impressive power-weight figure of 474bhp per tonne. To achieve this almost a quarter of all the 570S’s parts have been changed.

The carbon-fibre body (regular Sports Series models are aluminium bodied over a carbon monocoque) is of course a big part of the LT’s dietary regime – as well as helping justify what is a £36,000 premium over a stock 570S coupe.

Fast? The standard 570S already clocks 0-62 in 3.2 seconds and the LT is sure to be quicker – perhaps as quick as the 2.9 seconds of the 720S? McLaren is staying shtum on that, for the time being at least. It will be interesting to see if it’s still a 204mph car with that big spoiler on the back.

It will matter little because the 600LT is all out for maximum driver engagement and good lap times rather than mere acceleration, in keeping with the renowned reputation forged by previous LT models – one incidentally that has always ensured Longtails are among the most collectable of all McLarens.

The longer new carbon body, that giant fixed rear wing, new front splitter and side sills plus the giant new diffuser make up the aero mods. It’s all to do with downforce of course; though again, no figures on that for the moment, just the assertion that it’s “substantially more” than the standard 570S.

Making the most of that downforce are some significant changes under the skin, not least the addition of the forged aluminium double-wishbone suspension and lightweight braking system from the McLaren 720S. The engine mounts are firmed up over the stock 570S, and the steering, braking and throttle responses quickened. All 600LTs roll on Pirelli Trofeo R tyres.

And inside? Lots of Alcantara (it’s lighter than leather) and, as standard fare, the carbon seats from the P1. Pay more and you can have the ultra lightweight seats from the McLaren Senna. You will need those – plus the MSO options of carbon roof, cantrails and front fenders – if you want the car to hit its target weight.

That means the cost will rise – the car lists at £185,000 – but it’s unlikely to be a concern. What potential 600LT owners may have concern over is that McLaren will build too many of them. Well, the firm promises that it won’t. Like all previous LTs, this one should be reassuringly hard to get hold of, with McLaren planning on building it for just 12 months – starting October this year. There’s nothing to say they won’t do a convertible version though, as they did with the 675LT.

In any form, Longtails have always been McLaren gold, none more so than the F1 GTR Longtail that competed in endurance racing from 1997. Nine were built as stretched, lightweight versions of the F1 GTR that two years earlier had its famous outright victory at Le Mans. Longtails dominated the GT1 class in endurance racing but never won Le Mans outright. By the time McLaren Automotive resurrected the name for the track-focused 675LT in 2015 no one cared about that – as driving experiences go, it was McLaren’s best.

No pressure then, 600LT! We look forward to seeing it do its stuff – and hearing that new exhaust – up the hill at FoS in a couple of weeks.