its not so much the noise level im concerned about, its the amount of friction. With my e-revo, the gears were mod0.8, and it would freewheel for quite some time. My hyper hardly freewheels at all, theres a lot of friction.
I had a look at the gears on the HPI Vorza, and the pinion's look like what i should be using
http://www.hpiracing.com/products/en/100915/
they say 1M, is that the same as mod1?
cheers