Good, so I'm not the only one who thought that
that actually brings up a question I've always wondered about, though. What about the turbo in that truck (and some other turbos I've heard) makes that "choppy" tea-kettle-esque sound, when other turbos have a smoother whistle? Someone once said something about nicked blades doing it, but I've heard it on fresh turbo rebuilds also. Curious minds want to know 
That's possible to an extent, but in my observations, it also depends on the turbo. I used to volunteer on a boat that had twin Cummins 1710's. With the original turbos, you heard a smooth whistle...but, after installing rebuilt turbos on one engine, that engine had the "tea kettle" whistle. As far as I know, the turbos were the same models and same specifications; they were just fresh rebuilds instead of the tired ones that were originally on that engine. The other engine still sounded smooth.
