Originally Posted by bcfromfl

Hi everyone –

I finally was able to get a pro speed shop to install the ACE kit and fuel upgrades, with the work completed last weekend. We ran into a major noise issue with the PT50 BOV that was sent with the kit. It squeaked and chattered even at idle, and the shop owner said that it sounded like Tweety Bird. He wasn’t happy with it, and knew I wouldn’t be, so he opened up his race car and pulled out his Tial Q50 to install instead. There wasn’t enough clearance for the Q50 between the intercooler and a/c compressor, so he moved the intercooler ¼” with spacers. That got rid of the high-pitched squealing at idle, and moved the “chatter” from the supercharger into a higher RPM. Now, it does it at cruising speed, 2500-3000 RPMs, when there is no load on the engine. Just a constant chattering, from the driver’s side of the engine compartment. It's quite loud, and simply intolerable!

It’s the shop owner’s belief that it occurs because the supercharger is creating more pressure than the engine requires when cruising, and the pressure is cavitating out the compressor fan blades out the opening of the intake. He’s calling it a type of “compressor surge.” I’ve got the “hair net” filter on over the opening, and he said that if you could rig up a GoPro camera to look at the filter, you’d see it vibrating in and out when cruising. He feels that the solution would be to put a pancake H&N-type filter on the intake, so that the supercharger is always pulling against a slight vacuum. Or, if there might be an S-curved charge pipe that could fit a larger filter behind the bumper. Just something to create a small amount of vacuum on the intake.

I asked TopGunz about this, and he said that the solution is on the BOV side. He said to put the Tial QRJ on, with the Vibrant crankcase filter, and that will fix the problem. Unfortunately, the QRJ won’t fit in the space available, unless there might be a fitting available to turn it at a 90-degree angle…but then you’re messing with the free-flow operation of the valve. (Another option might be to have a 90-degree pipe and mount the QRJ remotely somewhere.) The shop owner is unconvinced that any modification to the BOV will fix the problem. He has installed dozens of s/c kits on Mustangs, and he said every one of those kits has a charge pipe with a pleated filter on it, and he’s never had an issue with this noise.

There are apparently different configurations available for some Tial BOVs, but none for the Q50. There simply isn't a way to connect any kind of pipe to it, to run to a crankcase filter...even if that would fix the problem.

What are the rest of you doing? Any suggestions? Thanks!