Quote:
Originally Posted by Josh@STILLEN
This is a harmonic dampener of sorts, on that point you're exactly right. But it's not to balance the engine, it's to balance the pulley ITSELF.
The factory pulley is NOT balanced, and the dampening employed on the pulley is to protect the engine from the outside influences going inward.
The factory pulley is a rough casting, done this way for cost reasons. To cut the entire pulley out of 6061 billet aluminum and balanced is an expensive proposition. They chose to cast the pulley, and add a rubber insulator to act as a dampener. Some other things can assist in dampening, the rubber belts and tensioners in the serpentine belt can help with NVH, and suitable when using a balanced pulley.
You can see the differences in the quality of the part...
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No offense intended, but this sounds like you guys made up this logic to sell your product.
The post starts by saying it IS a harmonic damper. But... Goes on to say that the rubber is put in this 6" cast pulley to protect the engine from vibration caused by the pulley. If that were REALLY the case, every pulley on the engine would need a similar damper. Small vibrations going in to finely balanced power steering pump would be way more damaging than small vibrations going into a 300 pound engine that has explosions going on inside that apply thousands of pounds of asymmetric load on the crankshaft. The bottom line is that the stock pulley is a harmonic damper and the Stillen unit is not. The vq37 is known for it's poor vibration/harshness qualities at high rpm and the stock damper is there to damp the vibration and harmonic frequencies. It may be true that the engine will survive to it's normal life expectancy without damping those harmonic frequencies, but the engine will be subjectively harsher.