You don't glance at this M3 so much as stare at it. It could be the luminous effect of the paint or the baritone rumble of its engine. In any case, people find themselves transfixed, the way a rust spot becomes the image of a religious deity.
In truth, Nik Saran of VF Engineering could care less about the car's appearance. He'd been driving all night, up and down Tejon Pass, a brutal 15-mile stretch of pavement cresting the Tehachapi Mountains. It's pretty much Mount Everest for cars. There are lots of bodies strewn about.
"People thought I was crazy", Saran recalls. "I kept pulling over and yanking the M3's front bumper off to take readings with the temp-gun. Folks thought I was going to shoot it."
It's unusual an outfit like VFE goes to such lengths to test its products. But that's the only way Saran would have it.
A supercharger is simply a high velocity air pump powered by the engine. The idea is if the engine breathes faster, it produces more power. Keeping the car from hyperventilating is the tricky part.
Before VFE starts bolting on parts, the engine bay is digitally mapped with a Romer coordinate measuring device. Parts are then prototyped with CAD and stereo-lithography and test fitted before final pieces are fabricated. The process saves time and can eliminate cutting into the existing metal.
The supercharger is based on a Roots twin-impeller unit and sits directly over the plenum. VFE chose to mount the Vortech V3 Si-trim supercharger with a CNC-machined aluminum bracket system made in-house. The unit is positioned in line with the original serpentine belt, which is replaced with a longer OEM belt. The bracket setup is created around a triangulated set of mounting points using factory hard points and fasteners. The bracket is machined from a solid piece of 3-inch 6061 plate and does not require the relocation of any of the OEM engine parts. The OEM hydraulic belt tensioner is relieved of its duty and replaced with another BMW unit. This allows the Goodyear Gatorback belt to reliably endure 8400 rpm. The belt setup is arranged to retain maximum permissible crank pulley and supercharger pulley wrap for optimal power transmission.
Cooling the boost or "induction charge" is known as "aftercooling," and while typically many forced induction kits use an air-to-air intercooler setup, VFE uses air-to-water systems for a greater cooling effect. Similar to what the company did with its E46 supercharger kit, they fabricated a custom replacement intake plenum chamber with integrated air/water heat exchangers. VFE plumbs the heat exchangers with their isolated water supply pumped with a Bosch high capacity electric water pump and cooled with a front-mounted, high-density-fin OEM water radiator. To increase its capacity, VFE designed a custom-molded two-gallon water tank tucked behind the front bumper. Air/water systems are typically used by many OEMs including Mercedes-AMG and Bentley.
ECU calibration was performed by GIAC, where the factory software was essentially reverse-engineered. Using diagnostic software, the engineers monitor and re-calibrate the entire ECU to function with an upgraded fueling system that includes increased capacity Bosch fuel injectors.
The end result is a neatly packaged forced induction system that increases horsepower from 414 to 610 hp at 5 psi on 91-octane fuel. Saran continued talking about the engine until my eyes glazed over. I think he would have been happier if the engine was on a stand all by itself.
Instead, the V8 is wrapped in factory sheetmetal accented with Vorsteiner's quality carbon-fiber bits, including the trunk lid and front and rear bumper diffusers. We have been very impressed with the overall quality of Vorsteiner aerodynamics. They're subject to brutal quality control standards that cull all but the best from the inventory. It's not unusual for Vorsteiner to trash a full third of a product run based on a single minor blemish.