Okay. I've been chasing down this problem I've been having. Let's see if anyone can help.
-Car has COBB w/ 93 octane ATR map, FBO with complete charge piping and upgraded DV's.
-2,000 miles OEM turbos. Replaced all vac lines. 24,000 miles on the car. IJE0S. Alpina Flash.
That's the mods that are relevant to my problem. Essentially, during part throttle, holding boost around 4psi or below with the throttle everything is spot on. Boost comes on hard with no delay. Once my throttle is pushed in enough to build boost more than around ~4psi, a loud air sound can be heard and my COBB tells me my boost is 1-2psi. This air sound and boost level will continue until I give it more gas (probably around ~60% throttle at this point), the sound will go away and boost comes up to where it should be (~12-14psi at ~60% throttle)
My initial thought when I heard it was boost leak. Sounds just like one, but it isn't. My entire intake tract is perfect. Smoke tested up to 25psi no issues, rock solid. No codes ever thrown. My WOT logs WGDC is spot on. It's just this air noise and boost loss that occurs and I can't figure it out! My next thought was maybe my rear turbo inlet tube slipped off during the turbo install. I haven't visually checked this, but I don't see how this could cause my boost loss problem during a certain throttle input range, and then make no noise after around 60% throttle. No oil on the downpipes (If the tube came off I'd assume there would be from the check valve, no OCC)
I'm confused at this point. WOT the car is strong, low throttle as well. My next thought is boost solenoids? Would this cause my problem by them going bad? At 24,000 miles?
Thanks for the advice. I have logs if you want them from today, WOT.
-Car has COBB w/ 93 octane ATR map, FBO with complete charge piping and upgraded DV's.
-2,000 miles OEM turbos. Replaced all vac lines. 24,000 miles on the car. IJE0S. Alpina Flash.
That's the mods that are relevant to my problem. Essentially, during part throttle, holding boost around 4psi or below with the throttle everything is spot on. Boost comes on hard with no delay. Once my throttle is pushed in enough to build boost more than around ~4psi, a loud air sound can be heard and my COBB tells me my boost is 1-2psi. This air sound and boost level will continue until I give it more gas (probably around ~60% throttle at this point), the sound will go away and boost comes up to where it should be (~12-14psi at ~60% throttle)
My initial thought when I heard it was boost leak. Sounds just like one, but it isn't. My entire intake tract is perfect. Smoke tested up to 25psi no issues, rock solid. No codes ever thrown. My WOT logs WGDC is spot on. It's just this air noise and boost loss that occurs and I can't figure it out! My next thought was maybe my rear turbo inlet tube slipped off during the turbo install. I haven't visually checked this, but I don't see how this could cause my boost loss problem during a certain throttle input range, and then make no noise after around 60% throttle. No oil on the downpipes (If the tube came off I'd assume there would be from the check valve, no OCC)
I'm confused at this point. WOT the car is strong, low throttle as well. My next thought is boost solenoids? Would this cause my problem by them going bad? At 24,000 miles?
Thanks for the advice. I have logs if you want them from today, WOT.