going with a smaller supercharger pulley will also reduce the noise and spin the blower faster.

I don't think it'd be enough to completely kill it though like raising the idle would

 

Can you post a sound clip of the noise?

 

+1 Smaller pulley - more boost - less rattle!

 

What supporting mods do I need to go one pulley smaller? Currently only have a Borla cat-back.

 

either a better FMU or meth injection. The guy that previously owned my kit had been running a smaller pulley for years and just a meth injection system and he produced a reliable 412 whp

 

test pipes

 

to run a smaller pulley? Wrong!!!

 

It is normal, I usually left / right foot at lights to bring my rpms to 800 which gets rid of it. No need to worry, I now have 50K miles on my blower and no problems at all... I had the rattle from day one of install as well. No mods needed to go to a smaller pulley really, I put on the 3.12 from the 1st day as well with no issues at all and I am thinking of putting the 2.8 pulley on sometime soon which I have sitting in my garage... I have a meth kit as well but have not installed that yet either.

 

Is this the rattle you talk about? If so, TOTALLY normal.. this is my vortech video and it was taken about 2 days after i installed it. I raised my idle to 900 and its fine now.

 

I am looking into FI for my car. I have been doing some research on this issue and emailed vortech about it...no reply. The vortech supercharges is basically a pump. So there are lots of things that effect the opperation of a pump. A pump does not "suck" it creates a difference in pressure. If we use the same principals as a centrifical pump, other then the fluid is a gas rather then a liquid. I figure this "noise" is one of the following:

1)Some type of cavitation in the system on either the suction side or discharge.
2) The "pump" not operating in its Best Efficiency Points (BEP). All pumps have a pump curve where the best opperation is between 2 point on efficiency curve. Operation outside of the BEP produces cavitation. Increaseing the RPM moves the pump up it's BEP curve to produce a higher flowrate therefore reducing the "noise"
3) Bearing clearence issues

The reason I figure it 1 of the above is because I troubleshoot industrial equipment for a living and that gravel sound you hear is usually a sign of caviation of the pump opperating out of its BEP...I could be wrong but I cant find anther good answer for this

 

My 05 G35 coupe is set up with a Vortech and and smaller pulley. The pulley did help take away the rattle some. Then I got a new twin disk clutch that makes all kinds of noise at idle. The car loves 10 - 27 degrees. Sounds Jet Solid. But above 50 degrees and after a 10 minute warm up, I will hear some noise.