i know this doesnt really belong in this place, but i posted in Engine Management, and all i got was people joking around, so hopefully some of you guys from here can help me out.

i recently reflashed my ECU with the cobb stage 1 91 octane map. about 2 days later, a noise developed while i hit full boost (14.7 psi). i drove for another day hoping it would go away, and now the sound starts around 7psi and progressively gets louder until i hit max boost. to describe the noise, it sounds like the "shhh" sound when you're boosting, except from 7-15psi its like 2 times louder that the regular "shhhh" sound. it seems like i may have a boost leak or something, but i checked everything out (intercooler hoses, uppipe, downpipe, BOV, and have found nothing at all. the car will even hold pressure with no problem. i used the live boost gauge mode on the accessport and saw no loss in pressure, nor did i feel any loss in power whatsoever. the car runs perfectly fine, but i know for a fact that this noise is not normal. I called cobb and spoke to one of the support guys and he told me that the sound is coming from my wastegate staying open when i am boosting, because my ECU is still learning. does this sound normal to you guys at all?

i am wondering if anyone that has a pretty good knowledge about subaru's or about the ej20t would like to go for a ride in my car, so i can show you what this sound is like, and hopefully you can point me into a direction so i can fix this problem. any help would be appreciated.

i was also wondering if anyone else has had this problem before.

mods list :
Helix uppipe
greddy evo catback
samco intercooler hoses
Cobb stage 1 91 octane map


thanks and any help will be appreciated

Nat

 

sounds to me that it is most likely your wastegate.

 

Wastegate flutter that
and maybe you need to tighten down the spring on your BOV.

 

I think if your wastegate stayed open then may not build as much boost, but what do I know.
I only noticed a 'woosh' sound after I put on a divorced wastegate downpipe.

If you have your stock BOV, put that back on and see if that makes a difference. Our cars only really need BOVs for making BIG power. If your max boost is 14.7PSI, then the stock BOV is fine. I am running the stock BOV, stock turbo and peak boost is 17.5-18PSI.

Try the BOV first since its a hose and 2 bolts. Also check the hose between the turbo and the boost solenoid (there is a little restrictor there) and make sure its not leaking. Though I think if it were leaking there you would be over boosting. Be VERY careful if this hose breaks, 20PSI might be more fun, but if not tuned right you can blow the up the world. hehe.