I want to hook my turbo inlet up to my stock air box.... I know people are going to hate haha, but I am trying to maintain the "sleeper" look and especially trying to retain the quietness of a stock truck. I think having a stock air box hooked up will help muffler (maybe?) some of the turbo whistle. I know.. I know why would anyone want to try to muffle the wonderful noise that everyone desires, I know it won't be 100% muffled but hopefully just a little more subtle.

Problem is I can't find any elbows anywhere. I see trick turbo has an elbow that looks re-enforced as well, just in case water or something gets in front of the filter then the turbo tries to suck it in and collapses the intake tube. But I want to get a 90 degree elbow and try to keep the air box in the stock location. The trick turbo one might work but I am not sure the sizes on it. My turbo has an extremely weird 4.1in OD on the compressor inlet so its been really difficult finding anything that fits. I wonder if I should look into maybe a Duramax air intake.

 

@TrickTurbo has certainly done this

 

Nothing wrong with a quiet truck. I have my Duramax so quiet you would think its stock untill it smokes you (literally and figuratively). Lol. I love a sleeper, I'm going to put as many mufflers as it takes to tame my 408, I'm over the noise. One would think the stock air box would definitely help with keeping the whistle subdued untill you whack on it. Then, I think it's going to be difficult to hide it...

 

How much bigger is a Duramax air intake? Rick might know what you want and how to achieve

 

I had a S475 feeding from a stock airbox 12 years ago haha.
Im 99* sure i used this elbow

https://www.intakehoses.com/reducing...d-to-4-id.html

Its been quite awhile ago tho.

It keeps it very quiet but dont expect to make too much with the setup.
I want to say around 7psi on stock 6.0 that it was starting to struggle. But for towing (2000 RPMS /6psi) it didnt seem to hinder the flow.

I tried factory exhaust and factory airbox along with a muffler on the wastegate. It was quieter than a stock truck and lil faster haha

 

Not sure the size on the Duramax intake. I know on the GMT800s they changed the intake to one completely different from the gas engines starting with the LBZ. It might not be any better.

As for the stu-tu-too compressor surge noise when you let off the throttle, yes I don't think you will ever be able to hide that. I personally don't care for it, some people think it's like the coolest thing in the world haha. I don't know how factory OEM engines hide it. I know on my Duramax it didn't make a stu-too-too but more of a very subtle woosh if you let off the gas quick under boost.

I wonder if the is a factory intake I am forgetting about that would flow more? I mean the only higher horsepower stuff would be Corvette LS9 and LSU but I don't think those would work at all or even come close to fitting.

 

There was a powernation video where they built a turbo truck and they had hid that compressor noise. I'd have to find it but they specifically mentioned it.

 

It seems like it shouldn't make that noise with a properly setup BOV, so maybe mine isn't working right. I know I am having issues making boost, I can only make about 2-3PSI according to my MAP sensor reading and during upshifts it will go up to around 5 or so psi. I have the supposedly 7psi wastegate spring in, but I am positive I can hear the BOV start to vent boost pressure when slowly rolling into boost at about half throttle. I also kind of suspect I could be making the correct boost but by MAP sensor scaling maybe could be off since I see about .9 grams of airmass per cylinder right before positive boost where the most I saw stock was about .75 grams so I don't think I'm magically taking in more air before boost.

 

Yours may be working right. They like built something or bought something specifically to hide the noise.

 

You can hide it withproperback pressure regulation thru cat and muffler. When I did the Duramax I went on a mission to keep it quiet. I did a ton a research and found by matching cfm of motor to cfm capability of the muffler you can control compressor surge.