well i was filling up and then heard this duramax with a loud whistle so i went closer and the dam thing was whistleling while it was idling do you just need to straight pipe my exhaust to make it sound like that? what i mean by whistling is the turbo whistling.


thanks Matt

probably was a later model. the truck with the vvt's tend to have more turbo whistle than the lb7's did. with a straight pipe, it will sound like a vacuum with a whistler shoved in the hose...

thanks so it wont be as loud as a newer truck you say?

I still barely hear my turbo, and I am straight piped.

And it is quiet at idle.........

I still barely hear my turbo, and I am straight piped.

And it is quiet at idle.........

i remember after i put my air cleaner on i was able to hear my turbo alot easier especially with the windows down so i think if i straight pipe my truck i will hear it more thanks for the info though.

i will let you know if i decide to do it:cool:

you can plug the tube that runs to the silencer "the black plastic cover on top of engine that says 6.6 Duramax"..that will help some.. When/If you straight pipe that will also cause a little more noise..

cut the muffuler out and put a pipe in its place.. thats what i did until i bought my 4".

-Colin