As if we needed one more reason...
From Grassroots Motorsports, May 2003
Quote:
The Weighting Game by David Vizard
Weight is a Racer's Worst Enemy: Part 1 of This Series Examines How Less Weight Equals More Speed.
...Crankshaft Torsional Damper
...It is commonly accepted that having the lightest possible damper may not be good for crank life, although it will allow the engine to deliver its best power. The reality of the situation, though, is that in terms of power, the reverse is almost always true. This observation is based on many hours of dyno testing crank torsional vibrations versus power.
A modern, quality camshaft profile is based on highly complex mathematical formulae intended to produce a profile that will generate, as nearly as possible, a smooth, minimal-vibration lift curve at the valve. All these equations assume the cam is rotated at a constant speed.
Many years ago, cam expert Harvey Crane was questioned about the effect of torsional vibrations transmitted from the crank to cam on their calculations. His answer: "It will invalidate all our computations and profile fine-tuning."
The implications here are that the valvetrain would then have less control over the valve motion, absorbing more power to drive it and causing valve float and/or valve bounce earlier in the rpm range. All of these factors mean less power, not more.
This is exactly what my dyno testing showed. On an engine of nominally 400 horsepower, swapping out a 14-ounce aluminum hub/pulley for a 15-pound--but highly functional--damper increased output by more than 11 horsepower. In addition to less power, the lighter hub allowed the crank to torsionally flex as much as 250 percent more than with the damper.
...To sum up crank dampers, the rule here is simple: Forget the weight and just make sure you get one that does what it is supposed to do--damp. This will allow the car to go faster, longer....
Side note: Where should weight be shaved?
1)Pistons, rings, connecting rods, and internal hardware (not for the faint...)
2)Clutch and flywheel assembly
