Manhart introduced its first tuning package for the BMW M3 G80 a year ago, but the latest product takes it even further in terms of performance. The MH3 GTR is the most powerful M3-based offering in Manhart’s catalog, with a whopping 641 hp (478 kW / 650 PS).

Visually, the MH3 GTR looks no different from the regular MH3, featuring the same splitter, bumper canards, side sill extensions, lip spoiler, and rear diffuser made of carbon fiber. The Manhart decal set is new, with silver and gray color instead of gold.

See Also: Manhart’s BMW M3 Looks And Sounds The Part

Inside, the highlight is the Recaro Podium bucket seats made of carbon fiber which are lighter than the stock units and make the M3 look like a racecar. The seats have leather-lined pads but admittedly do not look as comfortable as the factory-spec carbon-fiber seats of the hardcore M4 CSL.

Moving on to the most important feature of the MH4 GTR, the twin-turbo 3.0-liter inline-six engine benefits from the MHtronic auxiliary control unit, taking it to 641 hp (478 kW / 650 PS) and 800 Nm (590 lb-ft) of torque, an increase of 138 hp (103 kW / 140 PS) and 150 Nm (111 lb-ft) of torque over the stock M3 Competition. This makes the MH3 GTR 30 hp (22 kW / 30 PS) and 50 Nm (37 lb-ft) more powerful than last year’s MH3.

Also Read: AC Schnitzer Turns G80 BMW M3 Into Their Most Powerful 3-Series Ever

Other mechanical updates include the stainless steel exhaust system with valve control and quad 100mm tailpipes, finished in carbon or ceramic-coated. In typical Manhart fashion, OPF-Delete replacement pipes, sports downpipes, or racing downpipes without catalytic converters are also offered for export markets.

For the suspension, Manhart is offering two options – a set of coilovers by KW Suspensions or the standard lowering kit with H&R springs, both with a revised setup. The 20-inch Manhart Concave One alloy wheels finished in satin black are shod in Michelin tires (265/30R20 front and 295/30R20 rear). Stock brakes are retained, with golden-painted calipers spicing up the looks although Manhart can offer more options for those interested.

Manhart didn’t reveal pricing for the MH3 GTR but M3 owners can contact the tuner for the cost of each part. We guess that the exact same updates are compatible with the M3 Touring and the M4 Coupe.