So i rebuilt my td05 16g for my evo9 MR and put on a 20g compressor wheel and housing with anti surge. i am now getting a fluttering sound in 4th-6th gear between 2000-3000+ rpms at 1-6+ psi. at partial to very little throttle. manly when cruising at a constant speed with slight load. my wideband gage drops off to 10/1 (lowest reading) when i hear the sound. it did happen once at 12psi (max setting right now) as i haven't got it tuned yet. here are two videos of the sound. at the end of the first one is 12psi fluttering. Will getting it tuned fix this? i also think i'm running very rich as i am only getting 200 miles/tank and usually got 300+. i think i have gas in my oil as well. i am getting a EGR inefficiency code and dont know why either.

 

what bov are you running? it sounds like the bov tension is too stiff.

 

Its a greddy type RZ and I have the spring as lose as it will go.

 

not compressor surge. that is BOV flutter. some like these type sounds and its not harmful to the turbo.

 

So why am I getting it when I'm on the throttle?

 

The second video shows it better the bov and this are two different sounds.

 

thats your bov for sure, its too loose and bleeding off the boost at part throttle (imo). try stiffening it or an easy check if you still have your stock is to swap it out.

 

I have tried tighten the bov a little bit at a time to all the way and it doesn't help. I will be putting my old one back on to see if it fixes the sound. I initially thought it was the bov but after messing with it and not getting any change I started to think surge.

 

And its only doing this at low boost 1-6 psi if its the bov wouldn't it be worst the more boost I build up? When accelerating it doesn't happen. Only at constant throttle when cruising.

 

I would get a tune on there and quick. I have a similar set up i have a Tial BOV and that really helped get rid of that flutter. but I could recreate it so worked with my tuner to get rid of it. Mostly had to due with my tune.

Do the usual stuff and make sure you don't have any leaks vac or boost and then I would focus on getting your tune done then if still is an issue swap out the BOV.. Just my opinion.

 

You may want to check the diaphragm. Greddy BOV's are notorious for having problems with diaphragms. Yours may need replacement.

 

So I switched out the greddy bov with my old one, checked for boost leak and vacuum leak (none) and I am still getting the sound and its worse with my old bov. I can't cruise at all without having the sound. I guess the only thing to do is a tune. Will it be OK to drive it 3 hours as that's the closest shop to tune it?

 

How do you like the works 272's?

 

wait.... i reread your first post. you put 20gwheel and housing on your car without a tune? There is your problem haha, get it tuned!

 

Yah I would tune get the car tuned and then diagnose from there. See what happens after the tuner has some time with it. If you have to drive it I would just baby it and keep it out of boost if you can. If you can I would even talk to your tuner and see if they can send you a base map to flash the car and drive to the shop to ensure safety.

also what other mods are you running?

the Works 272s are okay. I wish they were more aggressive. I think I have squeezed as much power out of them as I can. I am looking to upgrade to the GSC S2's I think I have some more power in the car that is being left on the table.