Strange Noise post new exhaust fitted.

[wranga]

Gday guys. Today i bolted on a new redback exhaust to my 2000 Gu 3lt. 3" mandrel bent with no cat or muffler. Driving it home there is a noise in the engine bay that could be described as a woosh/whistle noise when the engine is under different amounts of load? ie cruising up a hill it will make this noise as i vary throttle input. No lack of power or any extra black smoke. But the exhaust note will change when this noise stops?? Why has bolting on an exhaust created this noise? Am i just hearing the turbo variable vain working as the exhaust is so much more free flowing? Any ideas???

[billyj]

your probly hearing the turbo whistling