Headers

[alex]

My current headers have 1 3/4 inch primaries going into 3 1/2 inch collectors, where the sidepipes connect, then back into 1 3/4 inch quad bend where the sidepipes exit the bodywork.

This is the way custom chrome seem to do it unless you specify otherwise.

Can anyone tell me if there would be a performance benefit in doing away with this intermediate 3 1/2 inch collector where the sidepipes join and just having the primaries connect individually into the quad collectors on the sidepipes ?

The way it is some of the primaries are very short before they join into the first collector.


Alex

[gareth08]

Hi Alex,
Don't know what youre running but when building headers for my 5.0 ltr I found that 1 5/8 primaries to a quad collector then to 2" connector then into 3" sidepipes restricted the flow (a friend has a flow rig)So mine are 1 5/8 primaries to quad collector then straight to 3" exiting the body and into side pipes with adjustable cones (from summit racing) to give a little back pressure and noise reduction.This setup had a 68% better flow rate than the old one.
Gareth