What's the best way of telling if I'm getting surge?

I can't tell if its the APS air feed or indeed compressor surge noise. I basically get a chattering noise on full throttle only when the turbo comes in to high boost, 1.3 bar. It's a VF34 on a 04 WRX engine running 346 bhp. If it is surge I wonder if it could be the SSQV causing this?

Any suggestions?

 

The spring can be too tight on the SSQV and not fully open, causing the air to go back over the turbo (just like dv delete) and make the noise.

 

Possibly although the spring on mine seems pretty soft compared t my old Blitz one. Can't you get the effect of to much air being forced in to the compressor also resulting it a stalling/surge noise?

 

Sounds like surge to me. Full throttle, hitting boost hard and making the flutter with your foot still down is surge.

Surprising to have it on the VF34 though?

 

Hmm that's what I thought. I'm going to change back to the recirc to see if that has any effect, failing that am I looking at a good adjustable bov do you think? Or is it the fact I'm running the monster APS induction?

 

Could be a combination of the two? Do you have a Fmic by the way?

 

No FMIC just STI TMIC. After doing a little more digging I've found out its more likely the boost solenoid, especially with this cold weather.

 

Yes it could be the cold. Turbo trying to boost more due to the cold and the ECU trying to reign it in.

 

It's surge due to the intake, the cars taking in more air than it can digest.