The argument for adding the forced induction was to give the high-strung V8 some more low-end grunt as well as boost overall performance. Of course, if you'd prefer a naturally aspirated 550hp V10 from the M5 in your M3, G-Power will also be glad to oblige. And they'll even throw a supercharger on that, boosting power to 730hp.
Those figures are all the extremes of tuning, however. G-Power does offer some less frenetic options as well, starting with the EVO I kit that adds 103hp, bringing the total to 517hp (386kW). This is done with a supercharger/intercooler setup, new enlarged fuel injectors to feed the hungry engine, an optimized stainless steel exhaust system and new electronics. The EVO II system does essentially the same as EVO I, but with an additional 24hp, bumping the final result to 541hp (404kW).
To make the jump to the EVO III system, G-Power adds a totally different supercharger system, a new cold air intake and a racing air filter. Helping out the improved airflow is a higher-capacity air-to-water intercooler, plus lighter pistons with a reduced 10.3:1 compressions ratio and strengthened connecting rods to withstand the extra stress.
For those wanting a palpable performance gain without such intrusive modification, G-Power also offers engine tuning services. The base-level G1 treatment gains 21hp (15kW), while the G1 Plus SII tune replaces the catalysts with high-flow units, swaps in a new exhaust and adds sport air filters for a total of 43hp (32kW) gain.
All G-Power M3s - whether the engines are tuned or not - can be equipped with the Highline aerodynamic kit. Consisting of styled and aerodynamically active carbon fiber replacement pieces for the entire lower section - front and rear fascias, side skirts and diffuser - plus the trunk lid and a spoiler, the kits promise better cooling and improved appearance.
Finishing off the G-Power performance treatment is a range of alloy wheel choices, upgraded brake systems, up to 25mm lowering springs and optional coil-overs, strut braces and anti-roll bars.
Inside, the buyer can choose from a wide array of G-Power branded accessories, including a carbon fiber interior, replacement pedal sets, gear shift knobs, and hand brake accents.