I get a chatter like noise from my split r valve, on low boost it chirps and then under full load its just crisp and clean
 
no the chatter is the standard dv being fooked leaking the vacuum so the excess boost pressure returned goes back to the turbo slowing it down causing it to stall hence the chatter noise, the new air filter just highlights the problems as the sound is no longer masked by the standard air filter.

so i take it a valve would prevent this then