My new induction kit has caused a chattering noise when changing gear at higher revs
Is this the Bosch standard recirculating dump valve or my waste gate chattering!!!!!!!!!!!!!!

Cheers
Darren

 

Darren, i also have a HKS filter on my WRX. Mine also chatters like crazy when changing gear as you describe. I believe it's due to the wastegate having to release more pressure due the increased airflow(because of the HKS filter). As far as i know it's normal and i think sounds pretty cool .

 

The 'chattering' noise is the car's standard recirc dumpvalve, it dumps the air from the turbo back into the system, you can here this through the induction kit

Sounds cool dont it

Paul

 

I have got an HKS induction kit and bailey evo dump valve (atmospheric valve) and mine still does this..

I didn't like it for ages but seem to have got used to it. It is less obtrusive with an atmospheric valve fitted.