Dinan D900-N55-S2 is Stage 2 performance engine software for BMW F-chassis vehicles using the N55 engine, excluding the F87 M2 and including supported X4 M40i applications. The calibration is designed to take advantage of supporting hardware such as a Dinan big turbo and upgraded intercooler. Dinan reports nearly 40 WHP and 60 lb-ft more than Stage 1 on pump gas, with gains exceeding 70 WHP and 80 lb-ft on race gas.