Matt Spiess’s BMW E28 originally came with a naturally aspirated 2.0 L M20 inline-six. He swapped that for a turbocharged 3.0 L M50 inline-six. The motor features a 2.5 L block, 3.0 L crank, Eagle rods, Weisco pistons, M54 intake camshaft, custom stainless exhaust, and Holset HX35 turbocharger. The combo made 400 horsepower to the wheels on a Link G4+ ECU and E98 fuel. A ZF five-speed manual transmission from a BMW 328 sends power to a BMW 535 rear diff with 3.73 gears.