900bhp twin-supercharged Mustang

Meet the world's best 'Stang

WILD HORSES
There’s no signage in sight: the only tell-tale sign that prospective punters have reached the home of Mustang specialist CoupeR Design is the row of half-finished Mustang projects lining the wall.

At the far end of the yard, the shutter is open and the chrome dish from a set of 20in CoupeR GTS alloy wheels shimmers a flash of sunlight from out of the blackness inside.
As we move closer a stocky figure emerges. Palms blackened with engine oil, he reaches out to shake my hand.
‘You guys finally found us then,’ says Matt Couper in his thick New Zealand accent.

I decline the greasy handshake and put my hand up in a totally British pseudo-wave action that feels ridiculous in the company of so much testosterone-fueled American muscle.

Matt, as his name suggests, is the owner of CoupeR Design and the mad scientist behind the creation we’ve come to see.

‘She’s back here; we’re just finishing her off,’ he tells us as he beckons us into the dimly-lit workshop. ‘We’ve not slept for two days. We’ve been too busy getting her ready for the shoot.’
No sleep for two days? These boys must have Red Bull in their veins and a do-or-die dedication to their craft to put in that kind of effort.

Away from the San Diego sunshine, it takes a few seconds for our eyes to adjust to the low light in the workshop. But when they do, it’s worth the wait.

SHARPER THAN A SURGEON’S SCALPEL
Flawless Cobra-black paintwork covers the 1967 Mustang Fastback from bumper to bumper; only a smattering of chrome details breaking up the expanse of evil.

‘The whole kit is a hand-made one off,’ Matt explains as he makes the final tweaks to the ‘Stang’s coilover suspension. ‘Only the roof line and the doors remain standard,’ he continues, without ever taking his eyes off the job at hand.

Looking at the lines of the custom kit, it’s testament to Matt’s skills with America’s favourite muscle car that it’s turned out so well. The quality and fit of the kit is superb, looking less like a hand-built one-off and more like a factory Carol Shelby special edition – that’s if Shelby had been doing a lot of acid at the time.
‘I call the car Obsidian,’ says Matt, ‘It’s the name of a black volcanic rock, made from molten lava, that’s sharper than a surgeon’s scalpel. I thought it was appropriate.’

Well it certainly gives the right impression; as something this malevolent could only have come from the fiery depths of the Earth - or the demonic mind of a Mustang master. ‘The concept started life as a sketch,’ Matt explains, running his hand through the air as if mimicking the car’s lines. ‘When it was finished I knew the car should be exactly as I drew it. No compromises.’

And that zero tolerance attitude runs right throughout Obsidian.

OBSESSION WITHOUT BOUNDARIES
‘I wanted the car to sit low on the rims,’ says Matt, ‘but the Ford running gear was too low to achieve the look I wanted.’

So instead of compromising his vision, Matt raised the running gear into the body shell to allow the car to sit lower. Encased in a flat floorpan – that increases aerodynamic efficiency by allowing the airflow under the car an uninterrupted pathway to the rear – the Mustang’s modified underpinnings is just part of the proof of Matt’s obsession with Obsidian.

As you look around the front of the car something seems strange. The classic Ford face has been given a modern twist. ‘We fitted ’07-model headlights to bring the front up to date,’ Matt smirks, flicking on the car’s high-beam and sending a blinding white light through my dilated pupils.
But it’s not the eyes of the beast that grabs your attention, it’s the nose; and it’s got me by the balls.
Towering like a monolith atop the Mustang’s extended and vented gloss black bonnet is one of the biggest power bulges I’ve ever seen.

With chrome air intakes at the front and extraction vents along each side, it looks more menacing than Darth Vader’s helmet. It’s so massive, It’s amazing Matt can see where he’s going!
‘I’ve built a full custom dash and moved the whole interior back six inches to allow a better view over the bonnet bulge,’ laughs the Kiwi craftsman. ‘It was a lot of work, but it makes the car much easier to drive – before all you saw was bonnet.’

WHEN 900BHP IS ENOUGH
But it’s what’s hiding beneath the bulging bonnet that’s the most impressive part of Matt’s masterpiece – a twin-supercharged, 5.7-litre V8.
Two slabs of polished metal are angled over the highly-tuned V8 like a pitched roof. ‘Those are the twin air-to-air intercoolers. They help keep the boost-charge cool. They’re cooled by the cold air flowing through the bonnet vent. We could have got more horsepower by going for air-to-water charge coolers, but these look so good I could never change them.’

When the twin Rotrex ‘chargers are spinning with full force they cram enough air into the engine to produce a gut-wrenching 900bhp.

‘We could run around 1100bhp if we increased the boost and remapped the ECU,’ explains Matt proudly, ‘but does anyone really need any more than 900bhp in a road car?’ Fair point.
Actually mapping the ECU is a lot easier than you would think, and it’s all down to the Big Stuff 3 engine management system that’s controlled through a 10in touchscreen monitor mounted in the dash.

‘I can adjust all the engine parameters from the driver’s seat,’ Matt says. ‘It makes mapping and tweaking the engine much easier; it can even be done ‘on-the-fly.’

And with that, Matt finishes the final tweaks we’ve been waiting for, slams the bonnet shut and beckons me into the passenger seat – it’s time to show me what this thing can do.

UNLEASHING THE BEAST
Turning the ignition key the engine fires on the second turn of the starter and erupts with the unmistakable roar of Ford’s V8. But this is different, while the classic burble is still there there’s something else adding to the cacophony: the superchargers. At full chat they whine like the children of the devil… and they’re hungry.

As we manoeuvre out of the parts strewn yard and back out onto the sidestreet, the ‘chargers hum a muted wail. A blip of the throttle and the ‘stang rocks in that classic muscle car style as the torque flows through the engine mounts and flexes the chassis.

We creep past the engine graveyard and out onto a more open, yet still deserted back alley.
Eyeing up ahead I estimate this must be around half a mile of arrow-straight tarmac. With no intersecting roads it dawns on me what Matt is about to do.

‘You might want to buckle up,’ Matt yells as he blips the throttle, his Kiwi twang appearing as calm as you like. I quickly reach for the belt and strap myself in like a man struggling with a life preserver as his ship goes down.

As the revs rise, the whine from the superchargers intensifies and the vibration starts to blur my vision. Matt’s grip tightens on the black leather steering wheel and he dumps the clutch.

The rear end squats and the sound of rubber being obliterated rips through the still Californian air. We’ve hardly moved when Matt snatches second gear, his hand wrapped tightly around the custom gear stick; moulded specifically to perfectly fit his own hand.

As second gear hits we start accelerating faster. The tyres are beginning to grip and are hurtling us down the street like we’ve been launched from a giant slingshot. With third gear engaged we’re hitting the full 900bhp and it feels like we’re riding a bronco stallion that’s trying to throw us from the road before our eight seconds are up.

LIFE MOVES PRETTY FAST
Whether eight seconds, two seconds or twenty seconds, I have no real idea, but the end of the alley way is approaching fast. Matt lifts off the throttle and the surge of acceleration drops. I look at my fingertips, which are now white and gripping hard into the edge of the custom dash.

The experience of a 900bhp Mustang is one that’ll leave you breathless and dying for more. It typifies the American dream in a way that burgers and breast implants could never compete.

Max could have shot this car a few days earlier, but I’m glad we waited. In fact, if this is what waiting gets you, I’m never going to rush that ketchup bottle again…

Vital stats:
0-60mph - 6 seconds
Top speed - 200mph
Engine: 6.4 litre V8, twin supercharged
Wheels - 10x20in CoupeR Obsidian GTS alloys