500hp Cayman GT4!

New York tuner DeMan Motorsport has made a 4.25-litre, 8,000rpm road rocket out of the flagship Cayman

Given a Porsche Cayman GT4, most people would be pretty content. As was made evident again in our Christmas twin test with a BMW M2 Competition, it's a superb sports car: exciting, engaging and hugely satisfying to drive. But for those not content, DeMan Motorsport in the US has a solution...

Its take on the Cayman GT4 sees the 3.8-litre flat-six bored and stroked to 4.25-lites; with new pistons, rods and crank, plus software work and a rev limit raise to 8,000, the Porsche is delivering 488hp and 360lb ft at the wheels - see the dyno vid below for proof. Assume a 15 per cent drivetrain loss and that's 561hp and 414lb ft at the crank, which are huge gains over standard. Apparently with titanium internals the DeMan GT4 could rev to 8,500...

Now if you're thinking that all this sounds quite pricey, you'd be right: $28,500 is the asking price, or about £22,500 at current exchange rates. That's without the Cobb access port or 'free-flowing exhaust' also required. But since when has modifying Porsches been an affordable undertaking?

DeMan apparently has five engines ready built ahead of announcing the package; those buyers wanting to keep their original block will have to wait six weeks. Perfect time to add in the Sharkwerks GT4 regearing as well, right? What a machine stands to be created then. And while this sort of investment will surely mean spending well into six figures on a Cayman - given the most affordable UK cars are still £70k plus - the prospect of a small, mid-engined, manual Porsche with GT3 RS performance does sound absolutely incredible. If any US-based PHers do take the plunge then we'd love to hear about it...