Porsche 911 fans, especially those who adore the classic-bodied air-cooled originals, don't like to see their beloved sports car radically altered beyond their original state. Porsche did a near-perfect job so why bother messing with it? That's just one way of looking at things. On the flipside, the Porsche 911 is a long-time aftermarket tuner favorite. The modification possibilities are endless so why not make a brilliant sports car even better? The purist vs. tuning debate will never end.

Jay Leno, for one, doesn't seem to mind tuned 911s, evidenced by his admiration for Bisimoto Engineering's 850 horsepower twin-turbo 911. Based on a 1975 911, it's beyond stock, to say the least.

Bisimoto is all about classic styling blended with advanced technologies so it started things off by adding some "modern optics," specifically daytime running lights. But it's at the rear end where those 911 die-hards are going to have some issues. Those turbochargers are fully exposed and are part of a 996-derived water-cooled 3.4-liter flat-six powerplant. Like we said, this thing is beyond what purists have in mind. Oh, and the Porsche emblem has been blacked out.

But what the brand purists need to understand is that sometimes heavy aftermarket tuning simply works, and does so very well. That's exactly the case here.

What also needs to be pointed out is that this 911 is still pretty bare bones. Just look at its stripped-out interior. There are no modern luxuries to speak of. Airbags? Overrated. All told, this 850-hp 911 weighs only around 2,400 pounds, so we're talking a seriously amazing power-to-weight ratio. Definitely not for the novice driver. This 911 is a solid example of maintaining an original spirit but infusing it with plenty of modern bits. The whole thing simply works.