Re: 4 inch vs 5 inch, turbo back vs cat back
A bigger downpipe will help keep EGTs
a little lower. If your truck is stock, you won't notice much difference in power. The bigger exhaust starts helping (performance wise) once you put tunes on and upping the power in other ways.
, go turbo back. Pipe size is entirely up to you. You won't gain any more power going to 5". The bigger pipe will make the exhaust tone a fair amount deeper though.
06' F-250 Harley Davidson CC SB
Lifted 6", 37" Nitto Mud Grapplers, intake, exhaust, gauges, tunes by Eric, GoGo Stage 1, Power Max, Strictly RR, Ported Uppipes, Swamps 58v FICM w/Atlas 80, 5r by Elite.
99' F-250 EC SB