The 15 best homologation specials ever

1. Ferrari F355 Challenge

While some manufacturers homologate their cars to compete in independent events, Ferrari, bless it, does things differently – setting up its own race series and then homologating (or more accurately, providing the kit so you could do it) a 355 to compete in it. But when the result is a car like the Ferrari F355 Challenge, who are we to grumble?

The 355 is one of the best-looking Ferraris ever made, a mid-engined supercar styling blueprint that inspires cars built 30 years later. The Challenge adds spice to the recipe in the form of a set of gorgeous five-spoke Speedline magnesium wheels hiding Brembo brakes borrowed from the F40 and a large rear spoiler.

Inside, there’s a roll cage, bucket seats and a fire extinguisher. While the drivetrain remained unchanged from the standard road car, the combination of a six-speed gated manual hooked up to a 380PS (280kW) 3.5-litre flat-plane-crank V8 makes for one of the most road-usable cars on this list.

2. Porsche 911 GT1

GT racing was where it was at in the mid-1990s. The BPR Global Series had taken the top-level GT1 class, well, global, with cars from Ferrari, McLaren, Venturi and more competing for glory. Porsche had been racing already with its GT2 car, but never at the top end of the championship, and really wanted a piece of the leading pie. Then it spotted a gaping hole in the rule book, and saw its opportunity. It turned out that rather than having to make an out-and-out racing car to some tight rulebooks, what it could do was build a racing car, and then nail together 25 road going versions, and the rulebook was suddenly very lax. Bingo, the 911 GT1 was born.

In reality it’s a 911 in name only, for one thing the GT1 is mid-engined, with a chassis derived from the 962 Group C race car. The GT1 race car had around 600PS (441kW) and was capable of 205mph at Le Mans. The original street-legal Straßenversion featured 993 headlights and just two were built, with a promise to competition authorities that more would follow. Eventually the GT1 race car was upgraded to Evo spec, which brought in 996 headlights. The road car followed suit and 20 were built in 1997. You might notice that that doesn’t add up to 25, but we’ll gloss over that. The road car had 544PS (400kW) and produced 600Nm (443lb ft), an almost incomprehensible amount for a road car in the mid-‘90s. When it was tested by Auto, Mund un Sport magazine, they discovered it could hit 62mph (100km/h) in just 3.8 seconds. In 1998 the race car was upgraded to GT1-98 spec, so Porsche built an extra car to homologate the new version... Yes, one, as Porsche quit motorsport (again) before it had to build the rest.

3. Audi Sport Quattro S1

While Audi's four-wheel drive Quattro took the Group B driver's titles in 1983 and 1984, the smaller, nimbler and mid-engined Peugeot 205 T16 had the measure of the Audi in the following years. A riposte was needed, and the Quattro S1 was it.

To beat the smaller Peugeot, Audi chopped 12.6cm out of the Quattro's wheelbase and plastered (what was left) of the original floor pan with glass-fibre, kevlar and carbon-fibre body panels. Meanwhile, Audi honed its warbling five-cylinder to perfection, building an engine that could sit at its 7,300rpm rev limit for 24 hours straight with no failure despite having a vast turbocharger producing 44psi of boost pressure. The result was a 1,200kg rally car that could accelerate from 0-62mph in 3.5 seconds on all surfaces. Sadly, it would take just two World Championship Rally victories before a series of tragedies saw Group B rallying banned in 1986.

4. Ford RS200

When Ford decided that it wanted to give Group B a go, it originally planned to use a variant of the super-successful Escort MkIII. It would be rear-wheel-drive and turbocharged, but the project came up against issues at basically every turn and they abandoned it in 1983 when the Audi Quattro was also proving that rear-wheel-drive was a bit old hat. After noticing this, Ford bosses insisted that a new project be started, for a ground-up rally car based around four driven wheels. The chassis was designed by Tony Southgate (he of Jaguar XJR fame), the body was by Ghia and the engine was a 1.8-litre Cosworth unit producing up to 450PS (336kW) in racing trim. It had all the makings of a rallying beast.

Next they had to build 200 kits and a single fully-built road car. Realising this meant the car really needed to look at least somewhat like a Ford, they set about raiding the parts bin. The rear lights came from an early Sierra, as did the doors and front windscreen. In 1984 the RS200 was born.

The layout is truly exceptional. That 1.8-litre engine is mid-mounted, and sends power forwards to a front-mounted gearbox. Power is then routed through a centre differential to all four wheels. It allowed for the low slung body and short wheelbase and make it look so good. Sadly it lasted for one season in rallying, with two high profile fatal crashes contributing to the end of the mighty Group B era.

- If you love the RS200, you’ll love our list of the eight best Ford RS cars.

5. Lancia Stratos

The Lancia Stratos was designed from the off to be a rally car. Evidence of this can be found in everything from its front and rear clamshells – giving excellent access to the mechanicals underneath – to its door pockets big enough to swallow a race helmet between stages. Of course, we could trust the Italians (more specifically Bertone) to make a great-looking rally car.

Power came from another reliable source – Ferrari. The Dino's 190PS (140kW) 2.4-litre V6 was mounted transversely, producing a silky-smooth howl contrasting the gruffer four- and five-cylinder engines fitted to the competition. The Stratos' mid-mounted engine gave it a 60:40 weight balance that was tricky to master but devastatingly effective, allowing you to guide the car around corners on the throttle without forcing the front wheels into understeer. No wonder it won the world rally championship three years on the trot.

6. Nissan R390

Nismo first built a GT1 car in 1995, with the Skyline GT-R LM. But it faced an almost-instant problem. While Nissan had built its car to the rules – converting a road car to racing spec – its rivals *cough* Porsche *cough* were smashing the rules to pieces. So Nissan decided it wanted a piece of that pie. They brought in Tom Walkinshaw, a man legendary not only for building fast cars, but for bending rules, and set about also circumventing the regulations. The result was the R390, a car styled by Ian Callum, with aero design by that man Tony Southgate, and the chassis, tub, greenhouse and roofline almost straight out of Jaguar’s XJR programme.

By the time it was finished no manufacturer was interested in building 25 road cars – so Nissan decided to build just one, and didn’t bother trying to sell it. The ‘road’ car has the same 3.5-litre twin-turbo V8 as the race car, producing 558PS (410kW) and a mighty 637Nm (470lb ft) of torque. Acceleration is similar to the 911 GT1, but thanks to a more slippery body the road R390 can allegedly do 220mph, but no one has ever tested that out.

7. Ford Escort RS Cosworth

The Ford Escort RS Cosworth was the first car to bring supercar looks and performance to the masses, but it was built to compete in the World Rally Championship’s Group A class. Its breathtaking looks came thanks to a functional aero kit – notably its picnic bench rear spoiler – making it the first road car to generate both front and rear downforce.

Under the Escort body, you'd find a Sierra floor pan needed to accommodate the car's four-wheel-drive system. Power came from Cosworth's four-cylinder YBT engine that produced 230PS (169kW)., the car's large turbo would later be swapped for a smaller version, making it more drivable.

Performance of 0-62mph in 5.7 seconds means the Cosworth still feels quick today, while a mixture of its performance and famously poor security meant it became a poster child for the joyride generation of the late ‘90s. Sadly, it never did win the World Rally Championship.

8. Peugeot 205 T16

If you hadn't gathered by now, Group B and GT1 will make up a decent chunk of this list, purely because these were probably the two greatest eras of road-derived racing cars. We've mentioned it already, but the greatest Group B car of them all (certainly in terms of achievements) was the Peugeot 205 T16. Of course to rally the car, Peugeot had to make 200 road-going examples, or at least the kits for them. The T16 may look like it’s just a beefed up 205 riding on higher suspension, but in reality, it is a lot more than that.

The T16 is driven by all four wheels and is powered by a mid-mounted 1.8-litre four cylinder engine, producing 200PS (147kW) – or half the power of the rally car. Interestingly, the engine is actually derived from the block of a Peugeot diesel engine and the gearbox comes from a Citroën SM. The body was built by Heuliez, who took standard 205 bodies and chopped them to pieces. But all of the trick suspension (mounted onto a tube frame inside the body of the 205), mid-mounted transverse layout and four-wheel drive pale in comparison with the coolest thing about the 205 T16 – the fact that in order to see the engine, you literally lift the whole of the rear body up.

9. BMW M3 (E30)

Yes, the first, and probably still most iconic, BMW M3 was born not of a desire to create the ultimate fast saloon, but to win touring car races. The M3 was presented to the public in 1985 at the Frankfurt Motor Show as a homologation car for both DTM and Group A motorsport. Mercedes had recently introduced the 190E to the DTM and BMW couldn’t let that go by without stepping up to compete. So the M3 had a close ratio gearbox, a lighter, glass-reinforced plastic boot, aerodynamic alterations, for both a small amount of downforce and a lower drag coefficient, and a limited-slip diff. The engine was derived from the popular inline-six S38 engine, but with two cylinders lopped off and now revving up to 7,250rpm. While BMW probably expected to win on the track – the E30 M3 won the Nürburging 24 five times, the Spa 24 four times and the World, European, British, Italian, German and Australian touring car championships – it probably didn’t know the legend it would spawn.

Unlike most cars on this list the M3 has continued in production to this very day, with the introduction of each new version the source of much rumour and excitement. Like most in this list, the original is now a highly sought after collector’s item.

– Like BMWs? Have a read of our list of the best BMW racing cars of all time.

10. Mitsubishi Pajero Evolution

The Mitsubishi Evo, that bastion of early WRC-spec rallying, made from the boring Lancer road car it would go on to dominate the... wait, no. You see, there was, originally, more than one Mitsubishi “Evo”. In 1997 Mitsubishi planned on having a go at the Dakar. At the time, in order to do so it needed a relevant road car. It picked the Pajero, a pretty boring early-era SUV, the contemporary model of which had been on sale since 1991.

What Mitsubishi created from it, was anything but boring. The Pajero Evolution is a two-door coupe, fitted with a 3.5-litre V6, normally found in sportier versions of the Galant or Eclipse, here producing around 275PS (202kW). Outside the Pajero sprouted a bonnet scoop, massive side skirts, mudflaps, a beefy bumper and, most excitingly, two seemingly pointless, Porsche 917k-style, fins. An astonishing 2,500 of them were built.

11. BMW 320si

While homologation specials tend to be exotic machines with price tags to match, that's not always the case – the BMW 320si is an example of a (very attainable) homologation special with prices starting for well under £5,000. Aside from its mild body kit and 18-inch BMW Motorsport alloy wheels, little hints the 320si was built to help BMW compete in the 2006 World Touring Car Championship.

The engine bay reveals all. You'll find a hand built 2.0-litre four-cylinder with increased bore, a reduced stroke allowing it to rev to 7,300rpm, and a jewel-like carbon-fibre engine cover. That equated to 173PS (127kW), 0-62mph in 8.1 seconds and a 140mph top speed. In race tune, the engine was enough to power BMW to victory in the 2006 WTCC, although it was a less successful road-going tool, with engine block failures a known issue. 

12. Mercedes CLK GTR

I’ve written extensively about the CLK GTR before, covering its racing success and the constant, and irritating, mix-up between it and the calamitous CLR. But the CLK GTR was also a road car, just as the other GT1 cars in this list, there had to be 25 road going cars to make it raceable. Initially Mercedes just built one, similar to the way Porsche had knocked a single car together to show willing. But when the programme carried on into 1998, they had to build all 25. The road car is barely different from the racer, not only to give a true experience, but also, Mercedes said, to save cost – on a car that cost $1,547,620.

Powered by a 6.9-litre V12 the only concessions to road usability were the addition of leather upholstery, the offer of air conditioning, two tiny storage bays under the doors and a little bit of traction control, to try and stop the everyday millionaire from killing themselves. Mercedes sold the lot, and so decided to make the last six roadsters – because what’s more comforting to drive than a pure-bred racing car that’s had some of the chassis rigidity cut out. And then, because the 612PS (450kW), 775Nm (572lb ft), 214mph top speed and 0-62mph time of 3.8 seconds on offer wasn’t enough, AMG built an even faster one. The CLK GTR Super Sport had a 7.3-litre V12 (an engine later used in the Pagani Zonda) and 664PS (488kW). There were only five Super Sports, so good luck ever seeing one on the high street.

13. Sierra RS500 Cosworth

What do you do to make the mighty Sierra Cosworth a completely unbeatable track monster? Well, you upgrade the turbocharged four-cylinder engine so it produces 225PS (165kW) and 277Nm (204lb ft), add a bigger intercooler, update the suspension and cooling, change the spoiler and front bumper and add more fuel injectors. Then you build 500 of them to homologate it to racing and go dominate the Australian, German, Japanese, New Zealand and British touring car championships as well as the Spa 24, Bathurst 1000, Sandown 500 and RAC TT. The Sierra RS500 has gone down in legend as part of the real genesis of modern fast European Fords. Oh, and it even won the Tour de Corse in 1988 in the hands of Didier Auriol.

14. Toyota GR Yaris

The Toyota GR Yaris was built to compete in the WRC (before anyone even considered selling it to the general public). It's a Frankenstein car that looks like a regular Yaris but has very little in common with its popping-to-the-shops brethren.

As a result, it has double wishbone suspension and a rear end taken from the Prius. Much of the body is aluminium, and the roof (much lower than standard Yaris for improved aero) is carbon-fibre. The engine, meanwhile, is a 1.6-litre triple that puffs power up to 272PS (200kW) for a top speed of 142mph and 0-62mph in 5.5 seconds. The adjustable four-wheel drive system serves up slides or safe understeer. Selling like hotcakes, the GR Yaris proves we still have an appetite for homologation specials.

15. Dauer 962 Le Mans

Perhaps the ultimate homologation special/rule bender. Porsche and Dauer, a team that raced Porsches in Group C, realised they could slip a Group C car through a loophole in the regulations for the Le Mans 24 that would later be smashed wide open by the GT1 revolution. You see the ACO, which runs the race, had not included a minimum number of road going cars to their Grand Touring rules, meant to be the second, slower class of cars racing. That meant that rather than building a long series of production cars to then adapt for racing, you really only needed to build one, and it could therefore be basically a prototype outside of all the rules.

Dauer had already started modifying their remaining 962 chassis to sell as the ultimate street racer, and some bigwigs at Porsche looked at the rules, looked at Dauer, and had an idea. Astonishingly the only modification that needed to be made to the 962 cars – that had won Le Mans in 1986 and 1987 – for the ACO to consider it a road car, was the addition of luggage storage. In fact, because the air restrictor for GT was bigger than that for Group C, the Dauer car was more powerful than the old 962. Even more astonishingly, the car is not the only road car based on the 962, as Australian Vern Schuppan also built a version. His didn’t go on to win Le Mans though.

If you didn’t know about the Dauer, perhaps you’ll be interested in some other weird ‘90s supercars you’ve never heard of…