QGMika

What drawbacks are there when a turbo intake pipe has too many bends?

cuatrokoop

Too many bends gives parasitic losses. There is a thing referred to as a "k" value in pipe flows. You don't want "k" values, they stand for a loss coefficient. Bends also screw with the velocity profiles in pipe flow, which can lead to undesirable characteristics (vorticity, undeveloped flow, etc).

Use as few bends as you possibly can, and make the radius as large as you can. Mandrel bent stuff is better, as it keeps the pipe diameter much more constant than "crush" bending does.