This has always perplexed me. What exactly causes the "Z roar"? I've read on some webpages that this is due to the fan clutch, but nothing I've read has really determined this with any certainty. Of course I'm referring to that unique almost whining sound that 280ZXs make (Do other models do this as well? I really don't know, hehe, but I do remember that the fairlady 300's don't do it). The car has always made that sound as far back as I can remember. Very unique and very cool, I think, but I'm just wondering what causes it. Anyone know?