Whistling after Motor/pulley swap.

Well I installed the new 383 and bumped my pulley up to 12#. After I set my Iac and tps I get a whistling sound in the throttle body (ported 52mm w/airfoil). Do any of you guys have this problem? I think it is the blades but all my values are good. I only get it at about 1500-3000rpms. It gets kinda of annoying. I thought it might be from the smaller blower pulley. What do all you guys have your values set at? Any info would be great, Thanks...John

I have the same problem, but its from my BOV. I don't have any BPV.. so the BOV somehow makes a whistle, put my hand infront of it and whistle goes away.

Ya, I have BPV. I'll try to check it some how. It doesn't whistling in park revving it, only driving down the street. My kit was for 8# originally, do you have to change the spring when you increase pressure? Thanks for the advice though......John

If you have the small BPV that comes with the kit, you may need to upgrade to a larger one. When you increase the blower output you need to dump even more extra boost when your not hammering on it. So when you cruising ~2,000rpms the blower is pushing out alot more then before, it is having a hard time getting out the small BPV so its causing a whistle sound. Put a strip of tape across the opening, you should be able to tell if its coming from the BPV then. You'll need to upgrade if its the case.

I will certainly look at this. Thanks again....John