I think its werid. WHen i stomp on the gas very hard it growls. But when i put it into neutral and rev it doesn't growl. Or if i put it in overdrive off the growling is less loud. Why is that. My rpms are high as hell and it doesn't growl. I don't get it. I thought the higher rpms more growling. DOn't know

 

I think it is the stress put on the engine when it is in gear at WOT. Thats my hunch, not sure.

 

You will notice the growl under load aka when your car is in gear and trying to accelerate. If you are in neutral and floor it for a split second you will still hear the growl, but you have to lift off the gas so quickly because you redline so fast that it's almost gone before it starts. It has to do with the throttle plate being open, not what RPM you are at.