doesnt look like it, seems odd especially for a supercharged vehicle

 

Yes, the crankshaft pulley is a DAMPER (dampeners get things wet, dampers lower the amplitude of vibration). Because this is a 4 cylinder, there is not a lot of inertia on these dampers. There is rubber between the hub and the inertia ring which created the damping. I know that our company (make vibration dampers) does not make this one, but I have quoted it in the past when GM wanted to do some market studies to get better pricing from Metaldyne and Hillsdale Automotive. Most engines that are made today have a crank damper. The twisting of the crankshaft that is created by the flywheel trying to keep the engine turning and the cylinders firing produces a resonance at some frequency. I believe, but don't quote me since it has been a while since I have seen the prints, that this engine is right around 300-325Hz. The fact that is is supercharged will increase the cylinder pressures and the magnitude of the tosional vibrations.

 

I don't think that removing it will drastically change any performance for the better.

A Light flywheel is about as much as you should shave off the rotational mass unless you plan to strip it down to a track only car..

 

The only problem with a light weight flywheel is that the damper is tuned to the stock mass-elastic system. When you change the rotating mass, the torsional frequency of the crank changes. On a naturally aspirated 4 cylinder this may ot may not be a problem, but with the forced induction engines and the high cylinder pressures that are found, you may be cutting the life of your crank. Since we do not have this damper in our production, I have not run the simulations to see what the actual response would be, but we do supply for all the Honda and Nissan 4 cylinder engines (naturally aspirated) and the result was unfavorable. The frequency would typically jump about 50-70Hz higher, which is outside of the tolerance of the damper's target frequency. This means that the crank is vibrating 50-70 times more per second which can cause excessive wear to the main bearings and crank. This will also happen when a light weight pulley replaces the stock damper. When the damper is replaced by a pulley, you remove all the damping, which is what we call a bare hub. We test bare hubs to see the actual natural frequency of an engine. This is the worse case scenario of the crank with respect to torsional frequency amplitudes.

 

That is basically what I was trying to say "I don't think that removing it will drastically change any performance for the better"

as in Negative performance...


Good and clear post BTW..

 

Thanks, I agree 100% that the results will be more unfavorable than favorable.