01uk300wrx

Hey guys,

I've just fitted a forge atmospheric dump valve to my o1 uk 300 but it doesnt seem to be working properly. I've never had any probs before when using dump valves on other turbo'd motors. Sometimes the valve is loud and other times its quieter when dumping at the same revs??? Also somtimes when the valve does blow loudly, when i change to the next gear (before i de-press the clutch) the volume of the valve goes from loud to quiet mid dump??. Has anyone got any ideas what would cause this