Hi all I have an evo 8 tuned on a three port, I notice at WOT the boost will oscillate very quickly (sounds like 40-50Hz). I am aware this is the Boost solenoid releasing pressure to the waste gate in order to maintain desired boost. I was reading Merlins guide to tuning and it said something about a bleed to atmosphere fitting in between the waste gate actuator and boost solenoid to remedy this. Anyone have any experience with this or know what the heck he is talking about?

 

i think most people run the 3 port without a restrictor.

 

So is boost oscilation just the nature of the beast so to speak when running a 3 port?

 

Try mounting it with a thin strip of rubber between the 3 port and the the metal of the car, that is if its not dangling around. It should reduce the noise a significant amount.