Porsche 993 with a 4.0 L Flat-Six

Gunther Werks set out to build the ultimate Porsche 993 they call the “400R” concept. The basis for the project was what would a GT3 RS version of the 993 be if Porsche had built one. The production run will be limited to 25 at a cost of $525,000.

Gunther Werks stayed with the air-cooled flat-six as the foundation for the power plant. However their version is 4.0 liters and was built by Rothsport Racing in Sherwood, Oregon. The engine uses forged internals, coil-on-plug ignition, twin spark plugs, and MoTeC ECU. This combo is good for 400+ horsepower, 330 lb-ft of torque, and 7800 rpm redline.

Behind the high revving engine is a single mass mid-weight flywheel and upgraded single-plate clutch connected to a custom built Getrag G50 six-speed transaxle. Inside the transmission find custom ratio gears and differential with carbon clutches. This combination is supposed to give the the best of track and street driving.

Gunther Werks upgraded the 993’s suspension with RS Spec EVO uprights, KW Clubsport coilovers and upgraded bushings, drop links, and anti-roll bars front and rear. They also included a KW hydraulic lift system to make sure you don’t scrape the front of the car over any speed bumps.

Behind the custom aluminum wheels are Brembo disc brakes used on the Nissan R35 GTR. They comprise of two-piece slotted rotors with six-piston calipers in front and four-piston calipers in the rear.

Performance was further improved using carbon fiber wherever they could. Every body panel was replaced with carbon fiber except the doors and mirrors. They also included carbon fiber on the floors, trunk liner, and racing seats.

Source: Gunther Werks (project page) and Gunther Werks FB page