Ok guys, I installed my 4# pulley today and have the same blower noise most everyone else has after installing a "non-dampened" aftermarket pulley. I have reads numerous posts regarding this subject and it seems to me Sal's explanation makes the most sense. He says the noise is coming from the blower gears when the blower is unloaded and it is dampened by the rubber-filled stock pulley (that sucker does have a lot of rubber). Some people refer to this noise as "cavitation", but technically it is not.

Whatever the cause, is goes away when the idle is slightly raised. It is usually only noticed when the truck is idling in gear because the RPMs drop, but when the truck is taken out of gear and the RPMs climb about 100-150 RPM the noise goes away.

I know people with chips will sometimes have thier tuner raise the idle to reduce this noise. However, I do not have a chip.

Now for the question: would there be any problems with increasing the idle speed by adjusting the screw on the throttle body that sets the closed throttle position? I know the computer maintains the idle speed by using the IAC. If this screw is adjusted to raise the RPMs thereby increasing the TPS signal to over 1 VDC, will the computer still use the IAC? I suppose you could re-adjust the TPS after adjusting the throttle stop screw. Anyway, any ideas on this will be greatly appreciated!

 

You have to unplug the spout connector with the engine running, then adjusting your preferred idle setting, reconnect spout, and it will remember the setting.

After having one noisey *** Cobra with a Novi 2000 RR, i dont know where you guys find these little annoying noises on your lightnings that drive you silly. Ive never owned anything this quiet!

 

****, where is the spout connector located? I assume this is similar to the spout connector used to adjust the timing on 5.0s. What exactly does this do?

Also are you talking about adjusting the idle with the screw or by raising it with the throttle and plugging the spout back in when you get it where you want it?

Thanks for the info...
Sammy

 

HAHAHA! Yes!

 

paxton rules!

 

I have a 5# and i dont hear any noises?