It’s safe to say that the aftermarket support for BMW M cars is generous. However, the M4 Convertible has never been as popular as the M2, M3, or M4 Coupe. G-Power aims to change that with a new upgrade package for the G83. It’s a predictably bold project, fully in line with the German tuner’s previous work on M models.
Based on the pre-facelift M4 Convertible, the “G4M Bi-TURBO” kit boosts the twin-turbo 3.0-liter engine to 700 hp. Moreover, torque is raised to a mountain-moving 850 Nm (627 lb-ft). These impressive figures target a niche of enthusiasts who wished BMW had given the droptop M4 the same punch as the M4 CS Coupe, but didn’t.
The added power comes from both software wizardry and hardware upgrades. G-Power fitted a new carbon intake system, modified the turbochargers, and installed HJS downpipes. The tuner also reinforced the eight-speed automatic transmission to ensure it can handle the extra torque.
BMW’s “S58” engine now breathes better thanks to a carbon fiber vented hood. The lightweight panel passed Euro NCAP’s pedestrian protection test, a requirement for road approval of the new hood. G-Power explains that add-on parts mounted at a height of 285 millimeters (11.2 inches) or higher must undergo such testing.
As part of the same procedure, even the custom carbon kidney grille was subjected to a collision test. To further beef up the car’s fascia, G-Power added carbon fiber attachments to the corners of the front apron.
The most striking visual change comes from the wheels. G-Power went all in with a forged 21-inch orange set, paired with height-adjustable coil springs for added visual drama and sharper handling. At the rear, beefy quad exhaust tips with new carbon fiber finishers leave no doubt this isn’t a run-of-the-mill M4 Convertible.
Like all G83s, this one comes standard with all-wheel drive, though you can still enjoy a tail-happy ride by switching to pure 2WD mode after disabling traction control. G-Power doesn’t provide acceleration figures, but the stock M4 Convertible with xDrive does 0-62 mph (0-100 km/h) in 3.7 seconds.
The tuner does confirm a significantly higher top speed, raised from 174 mph (280 km/h) to 192 mph (310 km/h). It remains electronically limited, meaning an uncorked version could likely go even faster.
Photos: G-Power
