Singer's Cosworth-powered 911 has just as much bark as it has bite

What happens when one of the world's most fastidiously built road cars is paired with one of the world's most prolific F1 teams? Engine noises to die for.

Famed for meticulous Porsche 911 restoration and modification projects, Singer Vehicle Design has now wrung their Williams-designed flat-six out on a track - and boy does it sound good. Like an old LeMans Porsche!

Surprisingly for a company like Singer, they've been using their own mule car as a testbed for their new engine. While it does feature some botched wheel-arch extensions and an un-'Singered' interior, the engine's crazy air intakes are present and looking good.

Even with unfinished wheel arch extensions, it still looks amazing. Shame about the weather, though.

Rated at 373kW (500hp) from its four-litre, air-cooled flat-six – or about 74kW more than the ‘old’ four-litre unit - this fuel-injected, rear-wheel drive monster is expected to stretch its legs out past 9000 rpm.

Featuring dual-oil circuits, titanium conrods, aluminium throttle bodies and carbon fibre trumpets, and an extensive use of titanium, magnesium, and carbon fibre, the Singer-Williams engine is designed to be both as light and responsive as possible.

What's more impressive, is how the engine manages to make an incredible 93kW/litre (125hp/litre) without overheating or blowing up. That output is impressive enough on a water-cooled engine, but in an air-cooled unit - that's amazing.

Remember - this thing has to be strong enough to survive a hard summer's day thrash at the track, while also being friendly enough for a day-to-day pootle to the shops. Did I mention that it also makes 373kW?

A few years ago 268kW was all the power a Singer needed. An extra 105kW is quite a jump.

There’s a whole bunch of other cool stuff about the engine too - like how legendary Porsche engineer Hans Mezger acted as a technical consultant - but if all the mechanical upgrades are used with the same ethos as the components in the chassis, suspension, and interior, the end result should be the coolest thing since, say, a regular Singer.

Is this as wicked as a Honda - or LS2 - powered 911? No, no it's not.

It's way better.

UPDATE - 15th November 2017

Just released on SingerVehicleDesign on Instagram, Singer has unveiled what the Williams-powered 911 will look like in its final iteration.

No idea how much it'll cost, but it'd be best to guess high. And then triple it. (image credit: singervehicledesign/Instagram)

Proudly adorning a light green paint scheme, juxtaposed with red 'Porsche' lettering and cream 18-inch BBS magnesium wheels, the restored 1990 Porsche 964 911's looks are enhanced with a full carbon-fibre splitter and central oil-cooler up front, a venting system for the oil-cooler at the side, and the ram-air induction system in the rear window. Nice.

According to their website, the Singer 911 will also feature optimised underbody aerodynamics, and an upgraded suspension system to be surefooted at speed that's lighter, and has better geometry and adjustability.

Did we also mention that the car will only weigh 990kg? That's about 186kg less than a supercharged Lotus Exige V6 - a car that isn't particularly famed for being slow - and that thing has 257kW (349hp)!

Extra goodie-goodies include Michelin Pilot Sport Cup tyres, Brembo brakes, and a six-speed manual transmission made from magnesium. Magnesium?

Note the integration of a small, secondary spoiler to in the rear glass. (image credit: singervehicledesign/Instagram)

In terms of the rear visuals, there are extra lashings of naked carbon-fibre around, and wider wheel arches to accommodate the rear track's additional girth. There's also a slim ducktail rear spoiler at the back for that extra X-factor (and for aero too, obviously) that instantly reminds us of the old Carrera 2.7 RS from the mid-70's. The exhausts should be a talking point amongst the Porsche faithful too, seeing as how every meticulous detail in a Singer is somewhat inspired by Porsches of old. No matter how small.

Is this the ultimate air-cooled 911? What engine would you shove in the back? Tell us what you think in the comments below.