In the Centerforce family
of clutches, the Dual Friction is the best compromise for street and track
driving. The Centerforce I and II level clutches have a greater street bias
compared to the Dual Friction and are considered an OEM replacement. The Dual
Friction trades a bit of durability, pedal effort and clutch smoothness for
increased holding capacity.
The Dual Friction trades a bit of durability, pedal effort and clutch
smoothness for increased holding capacity.
Breaking-in the Dual
Friction, I can barely differentiate the feel and engagement compared to the
stock clutch. The pedal effort and smoothness of engagement felt like stock,
which was a big surprise to me. When I did a clutch upgrade on my old Nissan
SE-R the pedal effort doubled, so I was expecting increased effort here too.
Doing a clutch job is also
the perfect time to do a flywheel swap. Thanks to MIQ reader DaGou, I learned
the AP1 flywheel is significantly lighter than the AP2 flywheel. The AP1 weighs
around 1LI pounds versus the 22 pounds of the AP2 flywheel. The reduction in
mass reduces the rotational inertia for faster flywheel acceleration.
Thanks to MIQ reader DaGou, I learned the AP1 flywheel is significantly
lighter than the AP2 flywheel.
Rotational inertia is a
function of mass and the radius, or the distance of the mass from the axis of
rotation. If the mass is removed from the same radius, we can assume the AP1
flywheel has about 2/3 the inertia of the AP2 flywheel. Torque, inertia and
angular acceleration are related to each other by the equation: torque =
inertia X angular acceleration.
Therefore, the same torque
input (the engine crank output hasn't changed) will result in the AP1 flywheel
alone accelerating 60 percent faster (22/14 = 1.57) than the AP2. Of course,
the clutches are bolted to the flywheel. The stock clutch felt about the same
weight as the AP1 flywheel, so I'll assume both clutches weigh 14 pounds. The
total mass of the AP1 flywheel/clutch combo is about 28 pounds versus 36 pounds
of the AP2 combo. The new combo has 7/9 the mass of the old combo and therefore
7/9 the rotational inertia, so the new combo should accelerate about 30 percent
faster than the old combo (9/7 = 1.286).
The engine crank output hasn't changed
So how much more responsive
is the new, lighter flywheel/clutch combo compared to stock? The Hondata KPro
comes to the rescue again with its data logging abilities.
