Porsche Manthey 4.2L Porsche 997 GT3 MR Debuts at Werks Reunion
Porsche Santa Clarita unveiled a rare Manthey Racing–equipped 2007 Porsche 997 GT3 MR at the Porsche Classic Restoration Challenge during Werks Reunion. The one-off build blends the analogue purity of the 997 with contemporary race-bred hardware, paying homage to Manthey Racing’s storied success and the legendary 911 GT3 R “Grello.”
The original 3.6-litre flat-six was sent to Manthey and enlarged to 4.2 litres, with output rising from 415 hp to 523 hp thanks to a bespoke ECU calibration, GT3 R intake, 997 Cup manifolds, an Akrapovič exhaust, and an upgraded rotating assembly. Chassis updates include Manthey-spec KW coilovers, Manthey control arms and alignment, a centre-lock conversion with BBS E88 wheels, and uprated brakes for track durability. Aerodynamics feature a Manthey front spoiler, GT3.2 rear spoiler, and signature “4.2” end plates. The exterior is finished in House of Kolor Kameleon paint that shifts from turquoise to purple.
Inside, Porsche Santa Clarita partnered with CarBone to create an OEM+ cabin inspired by Porsche’s Sonderwunsch program. Magenta Alcantara and leather accents contrast with purple carpeting, a rare 1968 Heuer Super Autavia motorsports clock replaces the standard Sport Chrono, and GT3 RS bucket seats flank a CAE short shifter topped with a purple heartwood knob. A 991-generation sport steering wheel and a colour-matched roll cage complete the cockpit.
“This build represents the pinnacle of what’s possible when we honour Porsche's heritage while pushing the boundaries of performance,” said Beau Boeckmann, President and Chief Operating Officer of Galpin Motors. “To our knowledge, this is the only Manthey 4.2 build of its kind in the country. It's a truly special car that embodies Porsche’s motorsport spirit while remaining fully street capable.”
The 997 GT3 MR made its public debut Friday, Aug. 15, at Werks Reunion as part of the Porsche Classic Restoration Challenge showcase.
