the exhaust cam hub alone is a significant upgrade to the OEM system

✔ Precision Fitment – Specifically designed for the BMW N55 engine

X21MXSGPS130

including the M3 E90

Internal temperature range: -10°C to 85°C

BMW M20 Pro-Xtreme Valve Spring Kit Nitrous Kit the exhaust cam hub alone5150 AutoSport Pro Xtreme Valve Springs for BMW M20 engines: M20B20, M20B23, M20B25, and M20B27. Maximize your engines potential with 5150 AutoSport Pro Xtreme Valve Springs, designed for BMW M20B23, M20B25, and M20B27 engines. Whether you're building for high revving street performance or all out racing, these valve springs are built to handle engine speeds of up to 11,000 RPM with confidence. Designed for Peak RPM Performance Perfect for high lift