Check your boost controller.

My stock turbo and 3076 does that at an agressive part throttle. It doesn't do it at wot, or light part throttle. I have switched the bov to 4 different ones, and even switched the turbo and it still does it. My last guess is its the boost controller.

 

This happened to my setup all the time if you went WOT in a higher gear at low RPMS. For example, in my MR if you were in 6th and went WOT at 3000rpms it would surge. This is easily solved by down shifting or going WOT near where your turbo is already spooling.

 

Can it be the wastegate spring? or dump tube?

 

Weird, it sounds like surge, like air coming out the compressor inlet though. Almost like DV flutter should fix it, but the BOV isn't sensitive enough to open so it is going out the compressor inlet, which is the surge that you don't want.

BTW, it doesn't sound at all like it is leaking.

 

It has the HKS race BOV

 

....same thing happens to me....

 

My 2g does that in 5th gear. Make sure your boost controller line is not sourced off the same line that your BOV is connected to. If it is (especially with EBCs) then the tiny bit of air that flows over to the wastegate/atmosphere can cause just enough pressure drop in the top of the BOV for the pressure in the charge pipes to lift it. Use a direct line from post butterfly to the blowoff if possible and make sure it isn't leaking (pressure test or get a new line) as a small crack can cause this also.

 

Exactly~!!! It happens on my car as well~! I thought it's because bov can't hold the boost(30+ psi) so I was gonna buy a HKS super sqv Racing BOV..I guess it's not a BOV problem anymore..what exactly is the reason for that?

 

vaccume leak or ****ty bov!!!!

 

that sounds like bov flutter not compressur surge

 

I was going to say check your vacuum/boost lines to make sure they are all hooked up to the wastegate and pressure source correctly, Just so you can tell the BOV is actually opening....

 

Definately it's not a BOV problem, because that thing happens when under partial boost, not full boost.