My car is stock. I have noticed at partial throttle load situations I can hear some slight flutter in the spool. Then when I increase the throttle the spool smooths out and the car may hick up or so and then accelerate. Also it may not do this all the time. I do not have a boost gauge and all vac lines are intact and connected and the BOV clamps are tight. Not sure if this is just a characteristic of this fast spooling turbo and other people are experiencing it or if I should look for a problem. Thanks for reading

update 09/09/08
Now not only does the car still have boost flutter I now have a whirling noise (sounds like a accessory belt is too tight) coming from the turbo area and a ticking noise from the turbo area that increases with throttle. The car makes these noises even when the car is stationary or rolling in nuetral or accelerating in gear. I think I may have a manifold leak. Any ideas? I am going to call the Mitsu dealership tomorrow and see about bringing it in.

 

do you have any aftermarket bov on ur evo X?

 

hey i have the same problem. i have an autozone special filter and after my Works reflash i start getting the flutter. im starting to think its the tube holding up the bov running to the front of the engine. it could be under heavy boost that thing vibrates to the point where its making the fluttering sound. just a thought. good luck with finding a solution.

 

iam getting it too during very light throttle around 40mph, i think its normal.

 

When I ran tests on the stock X, I really didn't notice the flutter. At least they fixed the bucking that is prominent on the 7-9.

 

I'm actually getting the "flutter dump" after installing a synapse Bov.

 

Do you have Port C connected to a boost-only source?

 

The only time I get compressor surge is if I'm in 4th or 5th gear at 2500 RPM's and build boost to 10 psi then let off to part throttle. The engine just can't consume all the boosted airflow at that low RPM that is coming in and you can hear it doing the CHOO, Chooo, Choooo, Chooooo noise as it flows back through the compressor side of the turbo. If I let off the throttle completely it doesn't do it but if you build some boost and let off to part throttle you can easily duplicate it on my car.

From what I've read our turbos are just a hair too responsive and quick spooling for our engines at low RPM, it shouldn't effect longevity as long as it only happens once in a while at low boost.

 

bump

 

i just recently started getting that problem too.

 

+1-its rare that I get it (once a week?) but when I do, I always turn the radio down and try to duplicate it..havent yet-but partial pedal, a little boost, and a let off, choooooo choo.
First I thougt it was the BOV, but then I kept hearing it and found it coming from the rear of the bay.

 

Yes it is rare. But I get the flutter while accelerating and not when letting off of the throttle.

Also the ticking and whirling sound I beleive is coming from the engine and not the turbo area.

 

My car is still stock..... but it is also very quiet!! all i hear for the most part is injector tick. I can't hear the bov in my car at all but I can feel it when driving if i go to pick up speed like say 5 or 10 mph from a current speed ill build a little boost then let off to maintain that speed it will flutter a bit but nothing I thought to worry about??... I also installed a boost gauge in my car and I don't see anything odd on the gauge while driving. you saying it happens while under accel. I haven't encountered this yet or at least haven't noticed it. I even messed around with the turns on the wastegate arm nothing odd. Since then I have returned the wastegate actuator arm back to stock though..... Have you done anything to the wastegate actuator arm?? You also said in your OP you were gonna call mitsu did you do so? did they help you out at all? have you bring it in or anything?

 

^Actually I updated my orginal post yesterday with the "update" I should of posted the date. I am going to call the dealership tomorrow after I get another opinion of the sounds from one of the motorcycle techs at my work.

 

mine is doing it also thru 2 and 3rd and through most of 5 with about 1/3 throttle it definitely sounds like waste flutter but i dont know if its the BOV or something else everything is stock and i roll the MR

edit i also hear that whirling noise only when its cold-mid temp in 1st to 2nd