I just recently installed my Injen intake along with the Injen UICP. Install was a breeze and the gains are noticeable

I took the evo to my local track this friday on a hot night and ran a 13.7 with a 2.1 60' at 103mph. Not bad for just an intake at an elevation of 2200' above sea level.

So now that i know my intake is performing I do have one question...

At part throttle im experiancing what i believe is bov flutter. Its either that or compresser surge, but one thing is for sure is quite audible under normal driving conditions and its driving me bloody crazy

Does anybody have a fix for this? Am i doing any harm to the turbo or any other engine components? If i replace the BOV with a HKS SSQV will it solve the flutter noise? Thanks for the help... Cheers

 

I was really considering this intake/uicp combo but the intake looks like has some resistance in the engine bay with that heat shield.

The fluttering sound might just be from the intake cone filter. Kind of sounds like a bov when you take your foot off the gas, but more of a hissing sound I guess. As for the bov, all you're using as of yet is the stock diverter... so it cant be bov flutter.

Have you considered tuning yet? You're probably running pretty lean. Looks really good though, I hope to see more posts/pics on this system.

 

I will be tuning after I get an exhaust on. I have AEM guages, wideband and boost waiting to be installed as well.

The stock diverter valve does make an audible dump/bov sound when i let off the gas but this is not the noise i am talking about. Nor is it the turbo spool sound/hiss.

The sound is specifically when driving in NORMAL mode / Auto under part throttle the turbo will spool and then a constant fluttering sound like the valve is opening and closing under partial throttle/boost. WOT there are no problems what so ever and also in manual mode its fine. I'm really stumped here!

 

It's funny you mention that. I am noticing the same thing at partial throttle, and I just installed AMS Upper and Lowers, with the intake and an fmic. Don't know what it is. A friend of mine mentioned it was possibly caused by the larger fmic, but thats impossible if you are experiencing the same with just the intake installed.

 

Okay after listening to countless videos on youtube i am positive that the sound im hearing is either compressor surge or flutter dump. Do you think my diverter valve is crapping out on me? Anybody else experiancing this? I just went for a drive and i can recreate the sound at will. Under part throttle i build boost and when the auto tranny shifts I get severe flutter like compressor surge. Im really worried now! Driving in manual corrects the flutter/noise but there has to be something more to it, isn't there? I mean this car has 2000 miles on it!

 

^ this sounds is normal and it is the BOV.

 

It sounds very close to this just not as severe

http://www.youtube.com/watch?v=LZUbo_mNDZM

 

part-throttle flutter is the wastegate jumping between open and closed - the stock wastegate opens at about 11psi, and if you're near that range the wastegate tends to open and close rapidly. it does no harm to the system in any way. this will happen even with an uprated wastegate actuator, but not as frequent.

strictly speaking, that is not turbo flutter. turbo flutter is when the bov doesn't open quick enough, letting pressure push back to the turbo, increasing the pressure on the fins and the bearing more than intended. this does increase wear and stress on the turbo. fluttering makes more of a chipmunk sound (um, go to youtube for chipmunk eating wood sound?), while wastegate being partially opened makes more of a "fft fft fft fft fft" sound. it's audibly differentiable.

 

Compressor surge not only occurs when the BOV doesn't open fast enough, it also occurs when the turbo is flowing more air than the engine can take in. This can happen when boosting at part throttle since the X's turbo does flow a lot of air even at low RPMs. What you're hearing is probably mild compressor surge. Yes, compressor surge is bad, but a small amount of surge at part throttle isn't going to kill your turbo anytime soon. I wouldn't be real worried about it. I can make the same thing happen on my car.

 

Whats real crazy is that i was super close to buyin the Injen Plumbing.Much cheaper the the AMS but i dont like the black polished look.i liek the black piping from AMS much more im actually about to order them now

 

Thanks for all the replys guys. I'm getting my wideband and boost guage installed next week and feel a lot better after reading endgame and scottspeed's posts. I can't wait to get these fricken guages installed so I can monitor what the heck is going on with my car. Also, Im headed back to the track this Friday to make some more passes

 

I want to see some dyno #'s! So curious as to how much performance this system adds.

 

I was considering this setup also, subscribed...

 

whrere is that track located at in the picture?

 

I noticed this sound on my Injen intake system as well and was going to post a youtube video for help! This thread has put me at ease