Approx... How much more horsepower/MPG's, with a full 4" exhaust With down pipe?

 

No way to know unless you hook it up to a dyno before and after the modification

 

I have the same question,what does the same change do for me as for 6.0 for the 7.3 liter motor or does anybody have any approx. .... # or experience. I now this is the 6.0 fourm but hey could you help me out.

 

You really need to put more exhaust thru the big pipe to see much differnce, don't belive the claims you see (15-20hp) A bigger exhaust cannot hurt a turbo diesel, only help it, the real important thing is to think of the EGTs with bigger exhaust. The stock exhaust is pretty good for stock, if you take the muffler off you will see a 50*+ drop in EGTs when you go to a full 4in exhaust you can expect to see more like 150-200* drop, this means a lot, heat is what kills a diesel and a turbo, with a bigger exhaust it is going to run cooler, look better, and last longer. If you put a fueling box on your truck, it is going to put more heat thru the engine-turbo, the faster you can get that heat out of the turbo, the longer it's going to last. I would stay away from the 5in. exhaust as they are known for resinating and not sounding as good as the 4in. exhaust. A EGT guage is a safety facter when you pull or really use the truck, it's then when you can see the real binifets of the bigger exhaust. With a big box (chip) I think you might see a 8-10hp w\full 4in. exhaust. And as for the 7.3, it's the same for any turbo diesel, the more heat you can pull out of the engine, the better!!!

 

I just put a 4" Turbo back system on my '04. I didn't do any Dyno tests before and after, But I did do the bfore and after burn out. Those back wheels will let you know if it helps! It is a noticeable gain. One of the other benefits that you can feel, Is the turbo spool up time is improved. It's still going to have some lag, But you will be able to notice quicker peak times. I found a complete turbo back magnaflow stainless system for $450 shipped. It fit perfect.