4" vs 5" Single Exhaust

[Palmer58]

Hi, thinking of putting a new exhaust on my truck considering it is still stock. I was going to go with the cheaper option and just do a single turbo back. I was wondering the difference between the 4" single and the 5" single. I know there is a size and a noise, but exactly how pronounced is it? Would buying a 5" inch sound much different/better than all the 4 inchers running here? Let me know what you think. Thanks for reading

[yngbuck19]

5" straight pipe sounds as throaty as the low end grunt of a 6.0L with less whistle of course but still sounds pretty badass I'm also running a 6"x48" stack

[backwoodsboy]

Won't notice any difference performance wise between a 4" and 5" pipe. The max DP size (without custom fab work) on an OBS is 3.5" with most people running a 3". That is going to be your restriction point. An addition inch after the downpipe won't effect the CFM that the exhaust can flow.
You will notice a difference in sound. 4" will let the turbo sing a little more, and the 5" will have more of a rumble to it.

[whistlin dixie]

i have a 5" and my trubo whistles pretty loud and it has a very nice tone to it

[Palmer58]

Thanks for the feedback guys I appreciate it.

[kramarj]

I got bored one day and took a video of mine. It is 5" and I love it, sounds real good. I know the sound isn't the best, but I think you can get the idea.
97 F-250 7.3 Powerstroke 5" Exhaust Start Up - YouTube

[FiberglassEater]

Originally Posted by backwoodsboy

Won't notice any difference performance wise between a 4" and 5" pipe. The max DP size (without custom fab work) on an OBS is 3.5" with most people running a 3". That is going to be your restriction point. An addition inch after the downpipe won't effect the CFM that the exhaust can flow.
You will notice a difference in sound. 4" will let the turbo sing a little more, and the 5" will have more of a rumble to it.

where is this 3.5 dp you speak of ? lol , im gussing you really gatta cut that firewall on the bottom to fit it in huh ?

[yngbuck19]

Here's a vid with my 3" diamond eye downpipe and 5" cat delete to a 6"x48" stack

1997 7.3 Powerstroke stack - YouTube

1997 7.3 Powerstroke stack - YouTube

[Fordpride]

Mine from in the cab. 3"dp 5" from dp to the top of the stacks

Gauge - YouTube

Gauge - YouTube

[Palmer58]

Thanks guys I appreciate the feedback. I'm going with the 5" I've decided I'll let you know how it goes once it arrives and is on.