Finally done doing my first working model of a air filter relocation using half my stock airbox.
I'll post some pics soon but this is what puzzles me.

I used 4" flexible tube as to cause no restriction and I took it out for a couple shake down runs at part and full throttle.
Right away I noticed quite a bit less noise coming from the turbo area, even with the windows down.
Then it kind of hit me...I was not hearing the woob-woob-woob when you let off under boost!
I pulled over to make sure there were no restrictions or anything came off and all was well.
I clicked it to high boost and the same thing, when I let out there was no compressor surge sounds!!
Wondering if this is good or bad?? The location is slightly restricted right now, but I felt no lag when stomping it from 20, 50, and 70m mph.
Anyone know why this good thing may be happening, or is it a bad thing?

 

A few pics of the set-up off the truck.
The hose laying over the tire is the 4"ID tubing I used, and the 3"-4' plastic reducer adapts it to the 3" steel pipe coming right off the turbo inlet.
The last pic shows it mounted under the box, passenger side before the wheel.
The inside of the body panel has enough curves in it to let air come in between the gaps, I may shift the whole assembly out just a little.

 

I have mine relocated and there is NO compressor noise when I let out under boost. Stopped immediately upon relocating. Things run great for me. I was told that the relocation would raise EGT's a little.

 

Kind of strange that its never been mentioned by any STS users here before, maybe I just wasn't listening but I swear I've never seen this posted before.

Its nice not having some of the weired sounds coming from back there now, but why does the compresser surge sound stop after just adding a 4 foot section of tube to suck through and a different filter element??
This is what I'd like to know, and why would doing this raise EGTs?
All I know is the wife will notice the difference as soon as she rides with me again.

 

The EGT will raise if the turbo has more restriction on the inlet side. (Why semi's have such large air filters. not that there EGT are anything near ours)

I bet your turbo is still making the same noise, Now the sound has a long way to go before you hear it.

Do you have any other pics of it under the truck???


Nice work by the way.

 

Don't think I'm getting much if any restriction, I'm using 4" ID tube that is internally smooth, it does snake around a bit but I may be able to solve some of that. The actual inlet on the turbo is less than 3" too.
I will post some more pics up today, I think I'm going to play hookey from work, supposed to be nice out then rain the rest of the week.

I think your theory is correct, the whole tube and the distance is acting like a muffler. Whatever it is as long as it doesn't make it slower and keeps the noise down its good for me!

 

More pics of the set-up.
Got the tubing from McMastercarr.

 

nice work, do you have a EGT gauge in you truck, if this there is no change of EGT I'll be doing the same thing.

 

Hmm...I wonder if I could fit that under my step, then, build a funnel to pull in air from the side of the truck

 

What's keeping the filter sealed against the lid?