Quote Originally Posted by alkygto View Post
How funny no one here has talked about rotor timing and lead-ins . There is more too it than just opening up the inlet and outlet to what looks good. Granted, the 3800 M90 does'nt get the huge gains in hp that the Cobra M112 does from a port due to its straight through design, but there are gains to be had. But what do I know? I'm sure another "expert" like copgtp will come in here and chime in. I'd actually like to hear what Reptile has to say about all this ( I respect his opinion), although I'm not sure if he messes with rotor timing at all or just ports the inlet and outlet.

BTW my dyno has about 100 hp to spin the M112 to 18000 rpm. Not sure on the M90 (yet) but it takes a bunch of power to turn these little bastards. Maybe hook one up directly to your transaxle .
Rotor timing is part of the reason why I don't suggest opening the outlet.

Ideal rotor timing also changes based on the speed at which you spin the rotors.

Would take some serious R&D.

Working with gen III blowers wouldn't be worth it considering gen V's are pretty reasonably priced, inlet flows much better and the coating is much better.

Gen V also pushes the rotors further into the case so the end of the rotors are open to the outlet instead of being shrouded like the gen III.