03quadduallyho

Who has changed their "out" pipe on their turbo for better economy and more flow? Can you use "off the shelf" or "self fabricated tubing assemblies" to make the air flow better and get better boost therefore better mileage? I heard something about a newer turbo outpipe or downpipe for my 03 HO that can be changed easily that will get mileage gains. Thanks y'all!

Note: My Turbo IN is excellent, I need "out" or "downpipe" help, only thanks!

rip 112

You can find a used elbow off of a 04.5-07 5.9, it is a full 4". As for downpipes, MBRP offers one, or any of the exhaust brands for that matter. You need a full 4" downpipe, then you'll be good for anything you want to throw at it.

Checkmate

I got my 4" pipe and elbow from the dealer for an 04.5 truck. The 04.5's have a cat. so they went with the bigger downpipe and elbow.

C Schomer

The stock muffler is the biggest problem - it's only 3" inside. I couldn't tell any difference at my power level when I went from 3.5 to 4 on the elbow and DP. Craig

Checkmate

I could tell a difference right away when I swapped on the 4" downpipe.....OH WAIT, that's because I also took the muffler off. Hahaha

stealman1

In your opinion if one is not looking for large power gains it is fine to leave the 3.5 exhaust and just get a new muffler?

rip 112

Yes, but the 4" downpipe will help a bit with egts and low end spoolup, not big gains, but a the little ones help out.

C Schomer

I did all my mods, one step at a time and I did the DP/elbow last and didn't see a noticeable decrease in egt at full load (towing) and full throttle on 100 hp. I also firmly believe that no two trucks are identical so it may work better for the next guy. It does look nice, tho! FLASH, now that I think about it - I added the glasspack/resonator (between the DP and 51" nelson at the same time - SORRY! So it did help a little cuz I now have two mufflers and no higher egt than with one muffler and the 3.5" DP. I'm still glad I built my own and saved some bucks cuz the improvement is small. Craig

Hanapaa

Anyone know where I can get a 4" exhaust elbow.

C Schomer

Sometimes they're in the ads or maybe ebay. I think a new one is about $65. I torched out a flange to fit the turbo and built a one piece elbow/downpipe.

Hanapaa

Mahalo, I will keep a look out.