I was wondering what the restriction (exhaust temp and horsepower) on keeping stock downpipe from turbo on a 2003 Ford F-250 Diesel 4x4 with 4 inch exhuast with flow through muffler starting at that point.

 

I'm not sure I can quantify the amount of restriction inherent to the stock downpipe, but I'd guarantee you that you'd see more benefit by replacing that, and leaving the rest of the exhaust system alone, than the other way around.

 

Thank you. That is what I was wondering. I thought I could save some money by not putting it on. That downpipe in 4" almost costs as much as the rest of the pipes.

 

Acording to the independant wrench I use that stock 3" down pipe and teh rest of the stock exhaust is responsible for about 6lb of back pressure. If you are going to change the back half it really pays to change the frount half. Kinda like only changing half of a tired team of mules. It really doesn't work to well.

PWRPROD