Smalller Diamter Pipes ?

[pastorscott]

On my 04 burb 5.3 I was thinking of reducing pipe size while installing larger muffler to mae up the difference. I was always told, that the bigger the pipes the more low end you loosse and the more top end you gain.

 

Scott

[Wingnut]

You go with a smaller pipe and you're probably going to bork up your motor from too much backpressure.

[Genuinefine409]

typically your ok with whatever size comes with most kits because they only effect the cat back. putting smaller pipe on won't really give you any advantage because coming from your y-pipe and through your cat will cause enough restriction to help keep you from looking all your backpressure. however there is no need for 4" exhaust either. whatever the kits use are pretty much what you need.

[DanMan_S]

On my 04 burb 5.3 I was thinking of reducing pipe size while installing larger muffler to mae up the difference. I was always told, that the bigger the pipes the more low end you loosse and the more top end you gain.

 

Scott

 

When considering exhausts you're always trying to maximize the exhaust velocity, backpressure is a quick way of saying that if you reduce your exhaust pipe diameter the exhaust gas velocity increases since the mass flow rate must remain constant. If you reduce the pipe diameter too much you're doing more damage than good because you begin choking the gas flow. Choking is the point where pipe wall friction and restrictions in the flow path physically reduce the maximum flow velocity. The smaller the cross sectional area of the pipe, the more the flow is choked.

 

So, it wouldn't work unless your stock exhaust was horribly oversized in the first place.