Quote:
Originally Posted by gil
Geo Metro XFI cam profile, that is a type of atkinson cycle. It closes early instead of Late. I also like the Idea of adding a turbo to compensate for the power loss.
|
Atkinson cycle is with an expansion ratio superior to the compression ratio.
It is not do-able with a shorter cam.
FE is doable with a shorter cam : you trade power for efficiency.
Making up a loss of power with a turbo is gonna also "compensate" the FE improvement unless the gearing is altered in such a way that friction improvement (less rpm) makes up for the extra power.
The best way towards FE is less weight / aero penalty hence less power required, power being fuel and air.
The atkinsoning of my engine would be mostly a way to reduce its power while improving its efficiency (I am sure you can imagine ways to reduce power without improving FE ...)
Anyway, I didn't find the Prius cam timing so far ...