United States president Theodore Roosevelt once famously paraphrased an ancient African adage thus: "Speak softly and carry a big stick." While Roosevelt was speculating on the nature of America's relationship with its world neighbors during an uncertain period in history, the maxim also lends itself particularly well to automotive performance and describing the ultimate elitist sleeper.
That said, here's the stick. Flaunting more than 600 bhp, this S600 retains all the refined features and silky ride quality that has made Mercedes-Benz a luxury icon. Owned and built by J.R. Granatelli of Granatelli Motorsports (GMS), the 2003 Benz is undoubtedly one of the most capable highway commuters we've seen.
Just a year ago Granatelli's ride of choice was an E28 M5. Later he began reading press on the new M-B E55, and out of curiosity he test drove one. He was impressed but felt it just wasn't as visceral as his BMW. Then a black S600 caught his eye, the salesman told him about its twin-turbocharged V12 powerplant, and he took a drive.
"It was fast...faster than the E55," Granatelli said. "I think these cars are the way to go over the AMG cars."
The only significant hard parts used in Granatelli's upgrades were the huge 20-in. Weld EVO Tech wheels and Bridgestone Potenza S-03 rubber. The rest of the upgrades are strictly electronic. Along with the wheels and tires, Granatelli installed Eibach's Pro-Tronic electronic suspension module to revise the S600's complicated underpinnings. The Pro-Tronic unit interfaces with Mercedes' amazing computer-controlled hydraulic suspension system, ABC, and allows the user to drop ride height by up to 40mm (1.2 in.). Eibach claims the module also fine tunes ABC's damping characteristics. Granatelli said the lowered stance allows his gigantic wheel and tire package to fill up the wheelwells without tucking up underneath the fender lip, common on vehicles running shortened performance springs.
Mods within the engine bay are also electronic. Granatelli increased wastegate spring preload so the turbos spool faster and raise boost by about 5 psi through ECU tuning. Calling on his years of experience tuning electronically fuel-injected engines, Granatelli himself remapped fuel and ignition curves to take advantage of the increased airflow. He claims the result is at least an additional 100 bhp, a figure that will only grow as he employs further upgrades down the road, including new cams, ported heads and larger turbo inlets. With comprehensive hardware upgrades and further computer tuning, he's convinced 700 or 800 bhp is not only possible but probable.
Granatelli's final addition was a RENNTech transmission ECM, another computer unit that plugs into the six-speed automatic which revises its shift points and provides a manual gear-select mode when burnouts are called for. This allows for more aggressive off-the-line performance and an expanded top end that comes dangerously close to 200 mph-not bad for a car that tips the scales at around 4,600 lb.
Granatelli described it best himself. "It's a 600-plus-bhp car that will do a burn-out so quietly your mother could be sitting in the car and she'd never know."