Tony O'Kane | Jan 20, 2009

Call us crazy, but we don't see anything wrong with the Mercedes-Benz SLR McLaren. Yeah, it's getting a bit long in the tooth these days, but with 460kW, 780Nm and a 0-100 sprint time of just 3.6 seconds you'd be hard-pressed to find someone who thinks the SLR could do with a bit of improvement.

The folks at Renntech, however, beg to differ.

Built to celebrate the company's 20th birthday, the Renntech 777 is without doubt the most powerful SLR built to date. Churning out a colossal 580kW from its 5.5-litre supercharged V8, Renntech describes the 777 as being not just a mere derivative of the SLR, but "what the enthusiasts were hoping for from the SLR, originally - which is a successor to the McLaren F1."

Supercar connoisseurs may debate that last point, but a quick glance at the 777's specs shows that - on paper at least - this thing has got the goods. A lightweight aero kit clothes the SLR's carbon-composite skeleton and looks mega-tough to boot while a sizable wing replaces the standard variable-angle spoiler/airbrake.

Lightweight centre-locking racing wheels complete the whole "race car for the road" look.

Renntech 777

The engine isn't just the standard McLaren-tuned unit either; Renntech have applied their own internal and external upgrades to help it cope with the boost in power. With more power comes more heat, Renntech have also upgraded the SLR's cooling system accordingly.

The SLR's automatic transmission has been beefed-up too, while Japanese driveline specialists OS Giken engineered a hyper-aggressive mechanical LSD for the 777 to help it get around corners (read: get sideways). Grippy Nitto NT-05 tyres have the unenviable task of transferring the 777's considerable grunt to the tarmac.

The first Renntech 777 is currently under construction and should be ready within a couple of months. A total of 20 cars will be built, but we can't tell you how much each will cost. As they say, if you have to ask...

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