Stock 305, thoughts on 3” tubing?

[Ugly1]

Backpressure kills power, low or high. A pipe diameter ( Cross sectional area), must be matched to the pressure drop (RPM) for the highest flow. Keeping RPM constant, if we decrease the pipe diameter we can increase flow to a point. Too small of a pipe can choke flow while too large will lack velocity. Therefore, exhaust pipe diameter can be used as a tuning tool to help move peak torque up or down the RPM band. Now intake runner and exhaust header length can be used to rock the power around the peak torque RPM. Then gearing to keep the engine in the desired powerband.

Which I did think of after the fact. But if a person only gives half of the information you have to go with the most common process that it is stock manifolds. But even that is only a shot in the dark.

 

[Jim Rockford]

Unless you are running massive hp your engine needs some back pressure. If you want more noise/sound, 2.25” to 2.5” with free flowing mufflers is the way to go

NO it doesnt , back pressure is a myth. It keeps you from being able to cram more air and fuel into the chamber. you want scavenging, Not back pressure. you also need to retune when you add a good freeflowing exhaust. lots of folks miss that part, install a bigger exhaust and they feel like they have lost power because they have,, you are now running leaner.

 

[Clone TIE Pilot]

Yep, when you flow more air you are going to need to flow more fuel too.