My Turbo has always made a weird sound at WOT. Instead of the normal sound of the turbo I hear that then sometimes a high pitched whine, kinda like when you hold a cell phone button down. Any clue??

Well a high pitched whine @ WOT sounds about right. I mean its spinning like 20K rpm or somethin so it will whistle. It probably makes all types of noise that we can't hear, dog whistle type stuff. So I would say that as long as its spinnin at WOT you are OK. Edited by: 403turbo

The pitch will change for sure. I believe that there is a resonator on the intake as well that is designed to dampen out some of the sound. A turbocharger that is the size that is on our truck is likely between 50K and 60K rpm at WOT. http://dieselplace.com/forum/smileys/Shocked.gif Some of the industrial machines that we evaluate have turbos that are the same size as a tire of of a mid sized front end loader and they are going 8 to 10K Rpm. Heck a few of the 2 cycles have 3 turbos that are twice the size of ours that run off of instrument air just to get the big windmill going so the beast will start.

Actually I think it is closer to 100K, someone posted the max imposed limit from IHI was like 125,000

There ya go, I new it would be a big number. No wonder when something goes with the turbo its pretty much garanteed to be catistrophic.

Im telling you though, It does it in the middle RPMs, not when its under full boosted. I've had Supercharged cars that I've spun the blower well over the limit they were suppose to be. I've ridden in Supras making 30+ psi.. Ive never heard this before.. Its like a tone from a phone. People that ride in it are like WTF lol.;

Just imagine the noise you would hear if one of the TC vanes broke off at 100K + RPM.....http://www.dieselplace.com/forum/smileys/Confused.gif