Why are 6.2L catbacks almost all 2.5" pipes and 5.3L almost all 3" pipes?

[Jackseric]

There's got to be something there my brain can't comprehend.  It doesn't make sense to me that all but a couple of the catback exhaust kits out there for my `21 6.2L are 2.50" and all the kits available for a `17 5.3L are 3.00" pipes.  What am I missing here?  I understand there are backpressure needs, but wouldn't more displacement at least dictate that this should be the other way around?  What am I missing here?

[PureZ71]

My AWE exhaust for my 6.2 is all 3"

https://awe-tuning.com/collections/chevrolet/products/awe-0fg-exhaust-silverado-sierra-1500-62l?p=1&s=best_match&seed=244901&iuf=true

 

 

[newdude]

On 1/11/2023 at 9:17 AM, Jackseric said:

There's got to be something there my brain can't comprehend.  It doesn't make sense to me that all but a couple of the catback exhaust kits out there for my `21 6.2L are 2.50" and all the kits available for a `17 5.3L are 3.00" pipes.  What am I missing here?  I understand there are backpressure needs, but wouldn't more displacement at least dictate that this should be the other way around?  What am I missing here?

 

 

The smaller size would be after the muffler.  6.2 is 3 or 3.5" off the Y pipe going into the muffler, 5.3 is 2.75" into the muffler.  All 6.2 have the factory dual exhaust as well.  The 2.5" would be the size of the post muffler duals.  

 

Corsa has 3 inch systems for both the 5.3 and 6.2.  

Edited January 12, 2023 by newdude