Turbo whistle what could it be?

[cre]

Originally Posted by turbonicsperformance

with the afm disconnected it goes into safe mode and you run really rich which in return spools the turbo easier than normal so its a more apparent noise.

Actually it doesn't. With the AFM disconnected the ECU merely reverts to a default base map, but it's not the same as "safe mode" aka "limp mode". The base map is tuned for the assumption of operation at sealevel (100kPa) and an ambient air temp of 70?F. It's the same map you run when the engine is cold minus the subtle tweaks for air flow correction. You should run around the low 14's when up to normal operating temps, IIRC. Given the absence of any real airflow data you may run rich if you're at a higher altitude or the air temp is higher.

"Safe mode" or "Limp mode" isn't set very easily and when it's active it's completely unmistakable... the car will run like CRAP (and barely that well). Unplug a knock sensor and go for a spin... it's awful.