HRM N55 head port plug kit 5inch Optimum OEp: F: 2551-0918-10 R:

Optimum OEp: F: 2551-0918-10   R: 2551-1170-00

Available in full set

while newer models such as the Audi S3 (8P) can be lowered between 10-40mm due to being much lower from the factory

2008-2012 E82/E88 BMW 135i N54 including 1M with Relocated Intake Inlets

HRM N55 head port plug kit 5inch Optimum OEp: F: 2551-0918-10 R:Have a higher boost N55? Our head port plug kit prevents boost pressure from entering the valve cover on the n55 where boost leaks can present themselves at the valve cover or internal diaphragm. *an aftermarket pcv system breather cap is recommended *professional installation is recommended. *intended for off road use only.