this whole thread is starting to crack me up. First off I have first hand experience with engines with flywheels that were to light. you did lose inertia which translates in to losing bottom end torque. I.E. technically you have not really lost your torque its been transferred to a different range in the rev band inertia wise. hmmm thats why track cars have lightened flywheels. It keeps the inertia down and the revs up. Translates to less bottom end torque. Now what are you guys missing here in the physics?
Oh ya your gonna compare a Honda engine (torqueless wonders to start with, with high lift cams stock )to a Nissan engine? Don't even get me started there . You can't run that comparision because the inherent build of the engines is so much different in terms of HP and torque . Its like comparing Apples to Oranges.
I stand by first hand experience in the field with stock flywheels ,extra light flywheels and midrange flywheels. Any you young bucks want to come down to socal and prove me and Old_s13 wrong? Don't bother. I was playing with cars when your butt was in diapers.
Oh ya mr KA with 11lb flywheel I bet your happy your KA finally revs half way decent because you have taken a lot of low drag off it . I bet that makes you feel like there is no difference because your so rev happy now you forgot. hahahahahaa
Been there, seen it, done it . I don't think most of you can that.