I would just fab up an 8" inch and be happy for a few years

 

Paint it with hightemp paint.....that should help it last a long time.

 

Sorry for the hijack, but here's something that I have always wondered about bigger pipes. If the turbo outlet is 4", then isn't that the smallest point in the system, and won't the exhaust only flow as fast as the smallest point will allow it to flow? (Kinda like a chain only being as strong as it's weakest link) I would really like to have the use of a dyno to do some real tests to satisfy my curiosity some day.

 

Mine didn't rust in the 2 years I had it on the truck. I won't go smaller than 5" on the next one either.

 

You've already got a perfectly good 4" stainless exhaust system, on your truck. Why not just replace the muffler with a stainless straight-thru one or a piece of stainless pipe. Shouldn't cost too much, at all.

With the money left over, why not apply that to a Smarty Jr. or other box & really "wake-up" the truck.

On my '03, the AFE intake system actually created a very small loss of power, in the stock form. Has something to do with the sensor seeing too much cold air or just too much air. It causes the engine to cut back on the fuel, very slightly, for some reason. A box or programmer will solve that problem.

Just my thoughts.

Joe F.(Buffalo)

 

Just replace the muffler.For YEARS it was said that a 5 inch was only usefull after 500H.P. not 450! Only since trucks started coming with 4 inch has the 5 inch been pushed.Marketing HIPE is what it is.All those folks whom made the systems saw their revinue going down the tube with 4 inch being factory.I darn sure would have NOT replaced my entire exhaust system if it had come with 4 inch factory.