Exhaust sytems

[dpsubaru]

Reading the article of exhausts (i.e. from the back pressure thread) the other day brought this to mind:

Seems that a number of exhaust manifolds have a 4-2-1 configuration, if you had just 4-2 with the two pipes running to two separate cats and then on through two separate systems out of the back of the car, all other things being equal (bore, box size, cat size etc...) with the original factory standard would it give any increase in power?

 

[old-git]

In a word..... No.

Each puff of exhaust gas down one pipe helps drag the gases down the other pipes. This is why 'proper' systems usually have equal length pipes so that the gas pulses travel the same distance and don't interfere with each other. Separating the system into two would mess up the flows and it would run like a modified Corsa

 

[Marius D]

Hey anyone. Just want to know what u think about firing order branches?Had some custom fitted on my V6...what performance and sound can one expect?My engine is not yet running as we are busy with the internal mods and gonna run6 throttles eventually