I have a 2006 Z with a Vortech V3 kit. Earlier today I installed the 2.87 pulley. Belts are at the proper tension and I machined the back lip so that it would not rub. Everything appears to be aligned belt wise, and the pulleys turn freely.

However, the unit is now loader than before. The whining sound that the Vortech normally makes is more noticeable, almost as if the bearings are louder. Again, I note no new tightness on either the belts or the pulleys.

Is this the same experience you have all had previously when doing this mod? Is it because the blower turns a bit faster now at idle?

Heading to get tuned tomorrow and want to see if this is normal so that I don't overheat bearings or eat a belt on the dyno.

Many thanks for your feedback.

 

i never ran anything besides the 2,87, but you are spinning the blower alot faster. if thats all you changed, then its normal

 

i think this is normal. i had the 2.87 pulley on first and switched to the 3.12 a few months later. i noticed that it was much quieter at idle with the bigger pulley. as str8dum said, you're making more noise cause the blower is spinning faster.

 

Their is a point near Idle 650 or just above that you will hear back-lash in the gears. If you sit in the car and raise the RPM just a bit, and it goes away- that's what your hearing. The answer then is to raise your Idle above that point to 750-850rpm.

 

My rpms at idle are at 900. I upped it when I first got the kit since that quiets the back lash sound although it increases the "supercharger whine". I guess I was a bit taken aback today by it being louder. I worried that it might have been a bearing issue with the pulley, although hand moving the pulley shows it to spin freely and smoothly.

 

Normal.

 

Mine seemed a little louder but ran smoother with less gear lash when I upped to the 2.87.

 

like stated it's normal. You spin a bearing faster it's going to make more noise. You would hear this noise increase as the rpms increase if the engine didn't drown it out.

 

Thank you all for the feedback. Had it tuned today. Reached 408 whp 330 wtq. This was on a Mustang AWD eddie current dyno, aka heartbreaker. Assuming a 12% correction factor to my last dyno run on a Dynojet, it would have been around 450 whp on the former.

Alas, I digress now. Nothing funner than couch dyno speculation... : )

 

Nice numbers!