anyone know how? I am having a boost fluttering issue.

full race manifold, gt35r, tial 44mm.

up to 18 -20 psi the boost is rock solid. if I go 22 psi, the boost fluttersfrom 20-22, if I try 25 psi it flutters from 20-25..... have tested a million things and when the boost flutters like this I can hear the wastegate hammering open and shut very rapidly.

I took off the wastegate and applied a small amount of compressed air to the side port and all of the air appears to blow by the piston. the gate opens if I apply more to it, but I'm wondering if the piston is leaking air when it shouldnt be. anyone know if this is supposed to happen? I took it apart and the diaphragm is good, re assembled and itoperates the same.....

can anyone help me

thanks, Pat

 

what spring do you have in there?

 

Sounds like you have a leak in a vacuum line somewhere between the gate and boost controller. I've never heard of a gate doing that. replace the vacuum lines and go from there if you haven't already. What boost controller are you running?