Real Stage 3+ power lives or dies on fuel delivery, and the APR Multi-Port Injection (MPI) System is the difference between a turbo that flows and an engine that starves. Built around four Bosch Motorsport EV14 980cc/min injectors, this system supplements the factory direct-injection fuel system with high-flow port injection, delivering the fuel volume needed to safely support Stage 3+ boost, E85, and M100 calibrations that the stock fuel system simply can't keep up with. Every component is engineered to bolt in clean: an APR-matched Bosch Jetronic-to-OEM harness, OEM-style fuel rail and rail sensor, APR fuel distribution block, and all mounting hardware are included, so the system installs onto the factory intake manifold without any custom fabrication. The MPI System is the hardware half of APR's Stage 3+ ecosystem, required alongside matching APR ECU/TCU software to unlock true Stage 3+ output. If you're already running APR Stage 3 software and looking to add the fueling capacity to go further, or building a custom Stage 3+ setup piece by piece, this is the component that makes it possible. Compatible across the EA888 Gen 3 (Audi 8V/8Y A3, S3, TT, TTS, Q3; VW Mk7/Mk7.5 Golf R, GTI, Arteon, Jetta) and EA888 Gen 4 (2022+ Mk8 Golf R, Audi S3) platforms.