The adiabatic efficiency describes the compressor, not the intercooler/water injection.

Water injection does not increase air density since the cooler, denser air is displaced by steam. It is used purely as a detonation suppresant. If you add methanol, though, that's a whole different story.

Roots: still inefficient, but band-aided.

 

I think I need to find some reference material on this. There is just too much I don't know. I love the off idle torque available with a roots type s/c, but don't like the tendency toward detonation. It seems like it might be fairly difficult to avoid. Still, I want a roots. I just need to learn how to do it. I'm still wondering how to actually get the water/methanol injected.

 

Have you ever checked out a Magna Charger? www.magnacharger.com I haven't been to their site yet, I just got the address out of a car mag. The pic looks pretty cool. kind of a roots style blower, but with FI not carbs.
Kind of like what GM put on the Pontiac SCed 3.8s.

I don't know if they make them for the f-body yet but if they want to make money I'm sure they will soon.

 

roots is the most inneficient really..

it'll make "instant boost", but top end wise....it's just NO. don't make torque like a centrifugal and the almighty turbo.