HARNESS ENGINE at LINDSEY RACING - Your Porsche HARNESS ENGINE - Porsche Parts Exclusively - Specializing in Engine, Transmission, Suspension, Brakes, Machine Shop Services, Racing and Hi Performance Auto Parts for Porsche. ENGINE WIRE HARNESS REPLACEMENT Lindsey Racing is the pioneer of replacement harness parts. Replace the portion(s) you're having problems with or purchase our full Porsche Harnesses » Schroth Racing » Products Porsche Harnesses; Porsche Belt for Carbon Seats. This belt fits 991 GT3, 981 GT4, and 918 cars with the factory Porsche one-piece carbon seat. It features a specific bracket for the lap belt installation that requires no drilling, and attaches to the factory engineered harness mounting locations.