Alright, everyone is super cool and has been helpful so lets throw this at your guys. So recently, I bought an Evo X, I posted before about the highway issue I was having and I figured that out but I have another issue. When giving the car half throttle in 3rd, 4th, or 5th..I get what I believe to be compressor surge. Now, my mods are below, someone told me it sounded like flutter and to replace the Tial QR BOV spring to the -6 black spring. I did that, after replacing the spring, the problem still exists except now it also vents if I am say building gradual throttle in 4th while still building throttle. If I give it gas or am in a higher RPM like 3800+ I don't get the surging. It only happens on throttle and I don't get it when releasing the throttle. We did boost leak tests and everything was perfect. Anyway, I think what I have is compressor surge and wanted to verify with everyone. The sound happens if I am in 3rd, 4th, or 5th and if I try to speed up at under 3000 rpm to around 3500 rpm. If it is compressor surge, would getting cams help stop this part throttle surging? What other mods would I need to do while also upgrading cams? Any assistance would be appreciated. Sound clips included below for reference. Thanks

Build List:
AMS Front Mounted Intercooler
Tomei Expreme Ti Turboback
AMS Cold Air Intake
AMS Lower Piping
Tial QR BOV with -6 spring (Black Spring)
3 port boost controller
Pro Tune
Stock Turbo

 

I am not familiar with tial bov's but looking it over the blk spring is the lightest?-thinking you need to go the other way and go with a heavier spring that keeps to bov closed--at least that's the way it worked on my forge bov. Keep in mind if your on a stock turbo--it shouldn't be surging at all especially at that rpm. you do have that bov recirculating rt?

 

dont have such a heavy foot when driving in low rpms in your higher gears. that is normal and it will happen. i believe your rods hate you when you do that. i would suggest downshift to get into the proper rpms before attempting to boost.

 

Sorry if this comes off as dumb, what would be proper rpms in that situation? This is my first boosted vehicle so I am in that learning curve with any car. I notice that if I hold off shifting into a higher gear till around 3800 like say going from second into third at 3800+ it doesn't make the flutter noise. The throttle on the car feels like there is such little leeway between out of boost acceleration and building boost that it's hard to stay out of boost, at least for me. Now, I love the car like I have wanted an Evo since I was 16 and I'm 27 now, so I have to figure out how to make this work. Maybe i'm sitting to close? Therefore, throttle position in relation to my foot is off so im having too heavy a foot? BOV and the setup is on correctly ( My tuner checked everything before we tuned it a few weeks ago ) I notice if im accelerating at say like 40 percent throttle, if I let the pressure vent for a second by pulling my foot off for a second, it accelerates smoothly. Maybe my issue is too much throttle at too low an rpm like bhsj13? Only problem is I feel like the car is trying to build boost even when i'm super light on it like I have to give it like 1-10% throttle which isn't very easy to do at least for me in order for it not to do it.

 

I had the same problem when I installed my turbosmart bov. You prolly installed the bov opposite to how it's supposed to be. Double check cause I am confident that's the issue. You prolly are getting more backfire too. If not its your spring.