7 Incredible Track-Only Supercars

1. Mercedes-Benz SLR McLaren 722 GT

People were never big fans of the road-going Mercedes-Benz SLR McLaren. Its carbon-ceramic brakes lacked feel, it weighed too much and the interior felt distinctly cheap. Thankfully, motorsport engineering company RML solved all these problems by converting the standard road car into a track-focused monster.

RML started by ripping out all the unnecessary gubbins from the interior including the heavy electric seats, substantial sound system and vast dashboard. This, combined with copious amounts of carbonfibre being swapped in, lopped a whole 334kg from the standard car, bringing the SLR down to a much more reasonable 1390kg (for reference the new Ferrari 488 GTB weighs 1475kg). A new fully-adjustable suspension system also helped to eliminate the standard car’s excessive body roll.

Thankfully the SLR was always endowed with a great engine - a 5.5-litre V8 - so RML only needed to give it a light tweak, raising power from 650bhp to 671bhp. But what really needed attention were the brakes. Thankfully, RML replaced the on/off carbon ceramics with ventilated steel discs, improving braking feel immeasurably.

The 722 GT also received some much needed aggression in the way of a new front splitter, skirts, a massive rear diffuser and a colossal rear wing. The cost of this conversion? £360,583 (€465,000, $516,370) plus a donor car. Worth it? Absolutely.

2. Ferrari FXX

Ironically, the Ferrari FXX - one of the finest track-only supercars ever produced - was developed for strictly non-competitive purposes. Run under the Corse Clienti program, the track-day special could only be driven at select events and most owners never took their cars home, leaving them in Maranello to be maintained by the factory.

The FXX was heavily based on the Enzo but nothing was left untouched. The standard car’s brilliant 6.0-litre V12 was increased to 6.3 litres, raising power to 809bhp; ample shove in a 1155kg machine. This was mated to a Formula 1-derived gearbox which could shift gears in 100 milliseconds (this was decreased to 60 milliseconds with the later “Evo” upgrade).

That Evo upgrade - made available to customers in 2008 - included new gear ratios, improved aerodynamics, a new braking system and an advanced traction control system. Power also increased to a face-bending 850bhp. The ultimate Italian Stallion could reportedly accelerate from 0-62mph in 2.5 seconds and would go on to a 214mph top speed. Watch it destroy the Top Gear lap record above.

3. BMW Procar M1

The BMW Procar M1 was one of the first track-only supercars. It was designed for BMW’s one make race series, Procar, which ran from 1979 to 1980. Procar took place as a support race for the Formula 1 Championship and allowed professional racing drivers to battle in equal machinery. Niki Lauda won the inaugural championship in 1979 and Nelson Piquet took the crown in 1980. Unfortunately, despite the close racing, the championship was scrapped in 1981 as it had served its purpose of ‘increasing brand awareness’.

Only a limited number of Procar M1s were produced, with the majority being developed by Project Four Racing. The cars were completely re-engineered, featuring 470bhp straight-six (BMW M88) motors, revised bodywork, wider tracks and stunning Campagnolo wheels. If only BMW had built a road-going variant to take on the likes of Lamborghini and Ferrari…

4. Jaguar XJR-15

Granted, this car is not strictly ‘track-only’, but it deserves a mention. Developed by Tom Walkinshaw Racing for a one-make race series called the Intercontinental Challenge by Jaguar Sport, the XJR-15 was a seriously hardcore machine. From the outside, it looked like a sophisticated supercar, but underneath the Kevlar and carbonfibre body was the chassis of the highly-successful XJR-8 Le Mans racer.

For road use, legendary designer Peter Stevens increased cockpit space, but that was about it. Powered by a heavy 6.0-litre, 450bhp, V12 the XJR-15 LM was a incredibly tricky on the limit. The LM version with its flat underbody went some way to correcting this flaw, but it was still capable of catching out experienced racers (see above). Weighing just 1050kg the road car could accelerate to 62mph in 3.9 seconds and would go on to a frankly terrifying top speed of 191mph. We’d love to drive one, but we’re not convinced we’d come out alive.

5. LaFerrari FXX K

The LaFerrari FXX K is a seriously fast machine. After producing the exquisite FXX, Ferrari had to deliver with the FXX K, and deliver they did. Thanks to new camshafts, a reworked intake and a new exhaust, this track-focused machine produces 101bhp more than the ‘bog standard’ LaFerrari, equating to a total output of 1035bhp!

This helps the FXX K to lap Fiorano a whole five seconds quicker than its road-going counterpart. This is partly due to the reworked aerodynamics which include an aggressive front splitter, active rear spoiler and two massive vertical fins, giving the car 30 per cent more downforce.

Out of all of the track-based racers on the list, this is certainly the prettiest. Unfortunately, we don’t have £1.9 million (€2.5m, $2.7m) going spare.

6. McLaren P1 GTR

How do you improve upon perfection? Well, if you’re McLaren, you simply tweak your halo car. Built to take on the LaFerrari FXX K and the Aston Martin Vulcan, the GTR is one serious bit of kit. The biblically powerful 3.8-litre twin-turbo V8 and advanced electric motor have been breathed upon to put out 986bhp to the rear wheels, and the track has been increased by 80mm to give the car increased mechanical grip.

McLaren has also reworked the aero package, ditching the active rear wing for a fixed unit. A new front splitter, dive planes and aggressive rear diffuser give the GTR 660kg of downforce at 150mph - an increase of 10 per cent over the standard road car. But don’t be fooled, even with the increased grip, the £1.98 million (€2.5, $2.7) hypercar is a hard beast to tame.

7. Aston Martin Vulcan

If you’re in the market for a track-only supercar, but the offerings from McLaren and Ferrari don’t look extreme enough for you, why not take a look at an Aston Martin Vulcan. With a 7.0-litre 820bhp V12 engine, carbonfibre monocoque chassis and LMP1 specification aerodynamics, the Vulcan is easily the most extreme car Aston Martin has ever produced.

Thankfully the car has been designed to be approachable on the limit. Aston quickly realised when designing the Vulcan that the majority of customers will be rich middle-aged businessmen, not used to slicked and winged racers. As a result, Darren Turner, Aston’s factory driver helped to design an accessible track-machine with phenomenal performance.

All 24 customers even receive a three day track tuition experience programme as part of an exclusive ownership package. All yours for the small sum of £1.8 million.

So, those are our favourite track-spec supercars. Which one would you take home? Or, in the case of the FXX, leave at the factory? Let us know!