[skhaliq]

Can anyone confirm whether the Downpipe has to be the biggest area of the exhaust system in order to make the most difference?

Or does the catback have to be bigger than the downpipe for more power and free flow?

Or if the catback tapers down, and the downpipe is bigger, is that better for free flow?

Just trying to get my head around exhaust gases?

Please advise?

Cheers!

 

[Aitch]

..well, it can vary with different setups I think, but I would be fairly sure that you can do what you like with the exhaust system but if the downpipes are too small it's pretty worthless. So i'd expect that the value of larger exhausts is at least to some degree governed by downpipe size and flow efficiency.

Aitch

 

[sean_goodman]

think of water flowing through a pipe.

only as effective as the smallest diameter