Post by
C-Kwik »
https://forums.nicoclub.com/c-kwik-u426.html
Fri Oct 18, 2002 10:24 am
Assuming the mechanicals do not fail, the biggest limiting factor for making power at higher revs is how well the motor breathes. And that has to do with the velocity of air in the intake and ports. Typically high lift cams are suited to this, but because they open so much, at low engine speeds, the air is not moving as fast past the valves. And with lower lift cams you get good velocity past the valves, but at higher revs, it starts to choke the motor. As such, higher lift cams tend to have more top end torque and lower lift cams moves the torque peak down.
Hondas tend to build their motors with more toe end in mind. And with VTEC motors, it uses a two stage cam set-up, in which during normal driving, it works off a lower lift cam lobe and after a certain RPM and load, it switches to a higher cam profile. This takes advantage of both. But even with the low lift cam profile, it is still more of a top end motor. The higher lift cam just tends to accentuate it by broadening the power band.