flywheel or pulley?!?

[JoeyD]

hughes, gone fishin...good posts. good information in both. gone fishin you hit my point dead on. Like I said I don't know the MZR like I do a 2JZ so I will settle for my point being confirmed in general.

 

[BadDSM]

I think there is some confusion as to what this harmonic balancer is supposed to do. The pulley itself does not need to be perfectly balanced. The harmonic dampener as the name suggests dampens bad harmonic frequencies that can be produced by the crankshaft. It can use a rubber isolator to quell these frequencies which unchecked can have the crank actually distorting and prematurely wearing itself and its associated neigboring components down. The longer the crankshaft (IE- inline 6's, supras, lexus, BMW 3 series) the more important it is to have a dampener as the longer crankshaft can more easily deviate from being "true". Just think of a long steel pole being held out in front of you and how much easier it would be to bend a 6 foot pole than an 4 foot pole. This longer pole has an easier time getting unbalanced. Each car reacts differently to aftermarket crank pulleys. Some AM pulleys reuse the rubber isolator portion of the stock pulley to bypass the problems inherint in a solid pulley while still cutting the rotational mass by using lighter materials. Some cars are known to have issues with aftermarket solid crank pulleys and some dont. How does the Mazdaspeed 6's engine respond? I have no idea.