HYPER VTEC keeps on evolving, without slackening.
|In January 2002, HYPER VTEC evolved into Spec II aiming
at letting everybody actually feel the power drive over
the entire ranges. As one of the aims of Spec II development,
it can be pointed out that the CB400 SUPER FOUR, the model
on which the system was installed, is the one having a
wide user class. There were voices to point out that beginners,
in particular, were unable to fully utilize the four-valve
stage from above the revolution range of 6,700. The development
team then developed HYPER VTEC SPEC II anew to enable
many more users to enjoy the four-valve stage of HYPER
SPEC II achieved increasing torque in the middle speed
range and smoother power by refining the valve timing,
inteke and exhaust systems, and the valve switchover timing
revolution from two to four valves was changed from 6,750rpm
to 6,300rpm. It has resulted in powerful and sporty engines,
enabling one to actually feel VTEC in all driving ranges
from low to top. In December 2003, SPEC III was introduced.
The switchover timing for a 6 speed only was changed from
6,300rpm to 6,750rpm to improve fuel consumption in cruising
over high speed roads without spoiling the cheerful drive.