I have read alot of yall have a missing silencer ring. What in the sam hell is that??

 

its a ring just inside the turbo that makes the turbo somewhat quieter. It is held in by a snap ring you take that out and it will whistle louder.

 

When you remove the air inlet pipe from the front of the turbo, you'll see a ring approx 3.5" in dia "smoothing" the transition into the turbo.

 

The whistle you hear when you take it out is turbulence caused by the ridges around the opening. The ring works like a funnel that directs the air into the turbo. Leave it in. It serves a purpose.

 

I took mine out, I've noticed no difference in sound or anything. I do have a stock airbox though. I'm probably just going to put it back in.

 

Ive noticed that since installing the silencer ring into the top drawer of my toolbox, the truck's turbo whistle is louder, but that top drawer opens and closes in absolute silence!

 

AFAIK, it was added at Cummins' request to quiet down the turbo. Other Holset turbos don't have them.

 

When I bought my truck it was stone stock. The first thing I did was add a K&N filter to the stock air box and take out the silencer ring and then the rubber boot between the airbox and inner fender. Instant joy! More power and now the truck sings too.