Exhaust dimensions

[Fabdoc]

I was wondering if anyone out there has opinions regarding optimal 4 into 1 exhaust header layout for a stockish Busa. Primary and collector diameter and length to start. If more advanced info, like collector merge angle, use of a bullet or not, etc is available I'm all ears. It seems like most of the street bike configurations are aimed at higher RPM output instead of powerband width. Ideas?

[busasandrail]

Gene has a pretty nice busa header setup. Im sure he can help you out with a custom design.
Ive seen guys run a modified street bike header with an aftermarket muffler.
El Toro uses an aftermarket(muzzy) system cut to fit the rail.

[turbomatt]

This is a set-up that I came up with for my Smart Car project, I needed it to not to be under the motor for ground clearance.
I talked to some guys who build mini sprint headers and this is how they do it: 4 into 2 into 1 design. The 4 pipes are 1&5/8 inches the 2 pipes are 1 7/8 inches and the main pipe is two inches




I sell mandrel bent stainless tubing but I only get certain sizes so this is how I made mine: 4-2-1- design 1.5 inch pipes pretty close to equal length into two 2 inch pipes into one 2.25 inch pipe. I really have no idea if this is right or not but it seems to work just fine the merge collectors are either really expensive or like in my case, very time consuming to make.
Matt