2011 wrx hatch. I am experiencing what I think is wastegate flutter. Mods (5 months ag0): Perrin CAI (many other non-engine mods: e.g. bushings, mounts, shifter, etc.) AP Stage 1 Recent Mods (last few weeks): Invidia Catless TBE Perrin FMIC GrimmSpeed EBCS GrimmSpeed Crosspipe GrimmSpeed Up pipe *all new gaskets for the above OTC Perrin AP Tune stage 3 tune (ran like s**t), then RS Motors tune (runs like a dream) (Noise was happening with both tunes though) At first I thought it was surge, then I did a bit more research and found a few good threads on the noise on NASIOC. I then thought it was a boost leak, but RS tested and fixed my main leak (boost tube to TB coupler) This video is the exact sound I am experiencing (not my car, but same sound). The part I am unsure of is what to do about it. Some say it is normal, not harmful and just to deal with it, others say to get it "tuned out." My tune is only running a hair over 18 PSI. I appreciate your thoughts and input, thanks!
http://forums.nasioc.com/forums/showthread.php?t=1081419 Every both turbo subaru's I've owned have had wastegate flutter (but not that whistling noise. apparently its normal, but I would find it annoying lol). Are you running a divorced wastegate DP? Apparently flutter is a bit more apparent with the divorced wastegate...both of mine had this type and I grew to like the flutter. Sounds like the Jetson's lol
I have the flutter, have since day one. No issues at all, except it does annoy me. I don't know if there is a way to get rid of it. Learn to love the Subaru idiosyncrasies.
LOL, definitely sounds like the Jetson's. My new Invidia DP does have a divorced wastegate side, so that logic holds up. I can deal with it no problem now that I know it's normal. Thanks fellas for the insight.
Ha! Jim I didn't know the car could move forward without that right most pedal firmly smashed to the floor...
I have a similar noise in mine and like everyone else said it is just the EBCS. If you go with a MBC it should go away. The EBCS uses PWM to control the wastegate opening so when you are at partial throttle and the turbo spools up it starts making more boost than the target, it opens and closes the valve very quickly to release some of the pressure to maintain the targeted boost. When you are at full throttle, the ecu targets a higher boost which will keep the wastegate closed (up to a limit obviously) and that is why you don't hear the flutter at WOT. If the frequency of the PWM was higher you wouldn't hear the flutter but that has to do with the ECU output and solenoid so if it really bothers you you will have to get a MBC. I personally like the noise, but mine sounds more like a chipmunk screaming into a megaphone, not so much a whistle like that but that is probably just the different turbo.
I knew that EBCS caused the loud flutter when used in conjunction with an EWG setup, but I guess it only makes sense that the same is true for an IWG. Duh!
