G-Power SK II Clubsport BMW M3 - Full Blitz

That old adage about how you can never have too much power seemed less and less valid while barreling out of corner after corner. Bolstered by a G-Power supercharger system, the V8’s response from just the slightest nudge on the gas pedal was instantaneous and savage, sending the traction control scrambling to rein it in and the rear end squirming as it tried to put down the power.

It sure seemed like too much power on that canyon road, but then trying to unleash 600 hp in such tight confines is an act that sits on the fine line between bravery and stupidity. Brave because there’s a sense of being strapped into something that’s beyond your control, like on the back of a rhino that has just broken out of a meth lab. And stupid because, well, that seems pretty obvious if you have any sense of self-preservation.
So that afternoon in the mountains was spent trying find that sweet spot where you’re making serious progress and flirting with the limits while at the same time keeping calamity at arm’s length. Given the explosive power delivery, calamity felt a lot closer than arm’s length.

If there are any complaints about the E90 M3’s V8, it’s the lack of low-end torque. Its over-square dimensions mean it’s designed more for high-revving power than off-the-line holeshots. Even so, it’s easy to just cruise around town without ever having to dip into the throttle or use high revs. But the power hungry are never satisfied.

We know of at least five companies who offer supercharger kits for the current M3. There’s VF Engineering, ESS Tuning, Gintani, Active Autowerke—and G-Power from Germany. This is the first G-Power-equipped M3 we’ve come across and we’re told only a handful of them are here in the U.S. That’s mostly due to pricing, as the kit in this M3, the SK II Clubsport “Sporty Drive,” costs roughly $20,000.

While costs did factor into the owner’s decision, reliability and reputation were what swayed him to G-Power. Knowing that German tuners have to pass TÜV approval and that the ASA supercharger G-Power uses has also been used by the likes of Alpina and TechArt reinforced his decision. Of course, the cache and exclusivity didn’t hurt either.

The SK II Clubsport package is G-Power’s most powerful system for the standard M3, which the company claims produces 600 hp and 427 lb-ft of torque. The company’s M3 GTS package puts out 635 hp. This SK II Clubsport kit is based around an ASA T1-522 “kompressor” and G-Power’s cast-aluminum intake manifold, carbon-fiber airbox, intercooler, larger injectors, cooler spark plugs, polyamide intake runners and remapped software. Boost, according to the company, is approximately 6 psi, which is actually one or two psi lower than some of G-Power’s competitors.

The whir of the spooling supercharger and the whine of the belts and pulleys compete against an Akrapovic GT4 titanium exhaust that growls and howls like guard dogs at the gates of Hades. G-Power also wrote new software for the dual-clutch transmission so shifts between gears are blink-of-an-eye quick, and engagement is firm.

Transferring the power to ground are a set of Michelin Pilot Sport PS2s. They’re mounted on a set of Interad Super Concave 10-spoke, three-piece, forged wheels that were custom-made for this car. When taken to the track, the car runs on 18-inch Apex Arc 8 wheels and Continental slicks. Those 18-inch track wheels dictated that the owner go with Brembo’s 365mm (14.4-inch) discs and six-piston calipers up front and 345mm (13.6-inch) discs and four-piston calipers out back. The calipers were painted G-Power orange for visual pop. KW Variant 3 coilovers replaced the stock shocks and springs.

As configured, the car rode firmly but always stayed composed. It dove into turns enthusiastically and didn’t mind late and trailing brakes, but turn-in response might have been slower than stock because of the wider disparity between the widths of the front tires compared to the rears. Instead of 20mm difference on the stock car, it’s 40mm, which in theory would mean more understeer.