[Mooyer]

This may have been covered before but hear me out. I work for one of the major car companies and I was talking to one of our tech guys about superchargers. The guy is a bit mental, but has a heavy racing background and knows them inside out. He was saying that most mass produced supercharger are produced in such a way that when the fan blades are cast there is usually a lot of burr (sp) on the blades. If you take your trusty dremel to the blades, you will get a lot more power.

Any one else heard anything like this before??

[Capsaisin]

At the speeds attained by the supercharger blades, you would be mad to take anything to them!!! I would imagine machining tolerances on the blades are critical.
Also, later s/c blades are coated. Any "fettling" would remove the coating.
Let us know how you get on.

[norm03s]

The rotors (your references i.e. fan blades) are precision machined before being coated. The case bore is also precision machined.
He maybe was referring to de-burring the case at entry and exit points. These are the locations the air entry duct attaches from the throttle body and the exit duct that attaches to the intercooler.

[Richard Crofts]

Dont touch the charger! The entry and exit points are known on all engines to be points of poor quality flow. Machining on castings for joints to air intake and exit is a well known fettling point from way back when. used to be significant gains to be made by fiddling with smoothing inlets etc on most cars.