porting bits? which ones to use
An air angle grinder is really the wrong tool also, it will be difficult to control and won't let you get into some of the smaller spaces. At a minimum, a straight die grinder, but the longer it is the easier it will be to deal with things. Most electric grinders are 2-3x as long as an air die grinder, and even with their greater bulk they're much easier to use and control. You'll also find that most air grinders really turn too fast to work well with cabide burrs.
Also, for stuff like throttle bodies and mafs, or anything fairly regular shaped, it's tons easier to just do it with a mill or lathe. I've done tons of work like this before by hand, and even then I found that stuff like that went faster chucking up the carbide bit in the drill press. Now that I have a mill and lathe, I've found that I can do this kind of work in a fraction of the time that I could in any other way by hand.


