Going to 4" tailpipe versus 3?

[015point9]

Planning ahead right now...truck is all stock,  maybe later add little power (not much) ...right now exhaust is 3 inch.  What benefits would 4 inch do from exhaust brake to exhaust tip?  Lower egt some?  Do I have to modify anything?

Thanks

[deehammer]

I went to a 4 inch MBRP exhaust I am completely stock as well. No modifications needed. Lowered my EGTs slightly but nothing to write home about. Sounds better is all real benefit I got. Stock exhaust was rusted out.

[Mopar1973Man]

Went from 3" to 4" and ZERO change in EGT's. Tunning on the Quadzilla does more to change EGT's than exhaust does. 

 

Drone is louder. The exhaust brake is louder. 

 

I did a 4" Diamond Eye Aluminized exhaust system with muffler. Cruising is quiet. Power band pulling up grades there is a spot where drone gets loud in the cab. Then every time I break over the top of Midvale grade and start hitting the exhaust brake coming down the back side its rather on the loud side. 

[015point9]

What about towing? Think it would help egt's any if you were towing a heavier load?  (Sounds crazy to me on the surface but towing 8 or 9 k trailer, the exhaust would have less resistance exiting) 

[Me78569]

3" isn't a restriction on a stockish truck.  

[Mopar1973Man]

Like this time around I looked at your signature... 2001 Cummins will have the HY35 turbo...

 

2 hours ago, 015point9 said:

(Sounds crazy to me on the surface but towing 8 or 9 k trailer, the exhaust would have less resistance exiting) 

 

The biggest choke point is your HY35 turbo with a 9cm² housing compared to HX35 with a 12cm² housing. This would reduce EGT's more than 4" exhaust. 

 

 

[Dieselfuture]

Mine is 5" not sure of brand po put it on, I don't have any real complaints about it. To each their own I guess.

[gipperkid]

The only real benefit on a stock-ish truck would be that lovely Cummins sound.