Ok, lets start by saying that temps have dropped to about 0 degrees F lately, so I dont know if that has anything to do with this either. truck is a 94 12V with 210k on it, 5 spd. #100, BHAF, wastegate unhooked. When I stick it to the boards, turbo sounds normal, then seems to get a little louder than normal, and then (only in fith geat does it do this, only gear I can hold long enough to do anything!) it starts to go into a whine, not a loud whistle, more of a slight whine. I have not checked for boost leaks yet, only cause its so cold out, but it has all the normal power, and EGT's are normal also. what does this sound like? I was figuring boost leak, but i also thought that a boost leak would show a drop in power? wouldn't it?
Thanks in advance,
Ryan

 

When I put in my #100 it sounded weird too. It was achieving higher boost #'s I thought wow my bro's truck with the same build doesn't sound that way. That's because I thought I had an HX35 which in fact I had a WH1C. With the #100 it was pushing beyond its comfort zone. Put big injectors in really sounded bad. Took out 2 inches of the divider in my turbine housing (check pic gallery) so I could regain wastegate control that made a huge difference, no more weird sound. It was due to big fuel and was the boost was out of control. Even though the wastegate was open it was only wasting the rear 3 cylinders while the front 3 had enough fuel that it was making the turbo still produce boost. If you think about the stress the turbo is under in that very condition it makes sense that it might sound strange. My advice is either drill a hole through the divider (access through the w/gate hole) or grind out the divider. I read a post recently of another member that drilled his and later on it cracked around the hole. Dont' know the load he had on it but cracks are bad. Another member told him to blend the sharp edges around the drilled hole might help keep it from cracking. With the way I did it I blended the partition so there were no sharp edges to interfere with flow. In short I suggest you modify the divider then you won't have such a load on the turbo. As for your gate I'd hook it back up and let it work just fool the signal with a bleed valve then you can control where it wastes at. Do that and I bet your sound is gone. I modded my stock WH1C to a hybrid WH1C/E (equivalent to a HX35/40) with an HTT stage IIII compressor kit WELL worth the upgrade.

JMHO from a bombed WH1C'er

 

That does make sense, although, I have been running this setup over a year, and it is just starting to make this sound now.

 

One thing I neglected to mention is that I after I installed my PDR I/C boots I noticed a boost leak where the elbow is clamped to the compressor, got that fixed and it sounded better but not cured. Might wanna do a boost leakdown too,

 

I noticed my turbo had a different tone to it this morning also.
I put it off to being -24°. Seems like sound carries better when it's cold.
Personally I'd wait till it warms up some and see if the sound goes away.