I've made some repairs to my turbo system, and now its running better than before I owned the car (03 stock). This means that I'm hearing some of the turbo noises for the first time, and have no other Evo to compare it all to.

What I am hearing is a BOV type noise under load (the sound is more pronounced when I lift but very similar), and am trying to determine if this is an intake sound, or a BOV leak. I'm only seeing about 17psi-ish unless I flog it, and then just touch 19. I'd love to see data on what the boost curve should be.

Is this noise proper or is it a probable leak?

 

well, you should hear a real high pitched noise... if it sounds like it's venting the DV is probably not closing.

 

I hear the "wheeeeeeeeeeeee" of the turbo, but also a whooshing noise very similar to when the BOV vents, but it is constant while under throttle and doesn't taper off like the BOV sound does.

I don't have the time to assemble a pressure test thing, but I can swing it by the dealer and get a new valve if that's the case. I have already had them look at it once before, and they said it was fine. In the 10 minutes they were staring at it, a whacked BOV and a good one probably look a lot alike.

 

I took the car out last night and held it at about 4k in 4th, and modulated the throttle. I could hear the BOV noise constant power on, then taper power off.

 

Turns out the vacuum hose for the fuel pressure regulator slipped off, messing up manifold vacumm real good. Now secured with a zip tie, I can hold 19psi very well. After fix I did see some puffs of soot in the exhaust, which may be some residual crap from the fuel richness the leak caused. Hopefully it will clear up, I'll have to keep an eye on that.