Director's Cut; amg takes control.(News)

Byline: MARK VAUGHN

The news with the Mercedes-Benz SL63 AMG is not simply that AMG planted another of its monster-good 6.3-liter V8s into yet another fine Benz. No, that has been done many a time to many a fine Benz already. Here, it's all about control in the design and engineering.

"This is the first vehicle in which all dynamic components have been developed by AMG,'' said AMG board member Wolf Zimmermann.

And that means a howlin'-fun big Benz roadster. In the past, AMG has assembled different combinations of engines, wheels and tires or suspensions, but there were always substantial, critical parts of the car that remained stock. On the new SL63 AMG, the in-house tuning arm of Mercedes did everything it wanted to do to whatever part of the car it wanted to bring within its considerable tuning charms. And they are considerable.

The SL63 AMG is like the director's cut of Ridley Scott's Blade Runner or Sam Peckinpah's The Wild Bunch-what they would have done if they could have done it.

The overall impression of this all-AMG product is one of superbly controlled mass-in this case, controlled by you, the driver. And there is a lot of mass, enough to remind you that this is a performance roadster, not a sports car. A stock SL550 weighs 4220 pounds; this AMG version tips the scales at 4334. That's no sports car. A Porsche 911 weighs 3075 pounds, for instance, and a Ferrari F430 weighs 3197 pounds. The SL is more in competition with the likes of the Maserati GranTurismo, which weighs in at 4136 pounds, or the Bentley Continental GT Speed at 5180. (Man, wouldn't that be a celebrity match race for reality TV?)

The heart of the beast is the 6.3-liter V8 that already has been transplanted, in a decidedly non-Frankensteinian way, into AMG versions of every Mercedes-Benz sedan or coupe except the SLK. In the SL, it replaces the three-valve, 5.5-liter V8. The new 6.3 makes a hearty and meaty 518 hp and 465 lb-ft of torque, thanks to variable valve timing on each of the four valves per cylinder, dual overhead cams and bucket followers. The whole engine is designed and built by AMG and its subcontractors, also a first.