Two Hayabusa's ago I got to looking at the stock header and sure did not agree with how Suzuki built the collector . The 1-2 and 3-4 pipes after merged have to run straight into a wall then the gasses ... well it's a wonder the stock Busa runs as good as they do IMO .
This mod won't be for everyone and the gain will not give more HP than a header and I wish I could offer carved in stone differences in oil temp , some sort of efficiency gain but i do know it's there and the mod , compared to many we buy or make is CHEAP !
I am not trying to beat the extraction characteristics of a header vs this stock pipe because it cannot be done . I just wanted it to breath easier and in the end it will be blowing spent gasses out two 50 mm slip-on exhaust exits vs one 50 mm exit of the Yosh RS-3 header cannister as some sort of example .
Yoshimura 4-2-1 header outlet is " I think " 36mm
Stock is " I know " 35mm
I was tired of giving the aftermarket alot of bucks , wanted to keep duals on this bike so just explaining what I've done is all
Neat thing about it is some work like building a stock looking exhaust for a sleeper engine when using an HMF front half , the exhaust all has to be on the bike . When done one side at a time , the muffler hanger bracket is the jig to keep the pipe exits straight
Stock header pic I grabbed off the net . Never mind that it's a 1999 model , all the collectors were the same .
My modified header
<!--EDIT|mountainmotor
Reason for Edit: None given...|1143306727 -->
This mod won't be for everyone and the gain will not give more HP than a header and I wish I could offer carved in stone differences in oil temp , some sort of efficiency gain but i do know it's there and the mod , compared to many we buy or make is CHEAP !
I am not trying to beat the extraction characteristics of a header vs this stock pipe because it cannot be done . I just wanted it to breath easier and in the end it will be blowing spent gasses out two 50 mm slip-on exhaust exits vs one 50 mm exit of the Yosh RS-3 header cannister as some sort of example .
Yoshimura 4-2-1 header outlet is " I think " 36mm
Stock is " I know " 35mm
I was tired of giving the aftermarket alot of bucks , wanted to keep duals on this bike so just explaining what I've done is all
Neat thing about it is some work like building a stock looking exhaust for a sleeper engine when using an HMF front half , the exhaust all has to be on the bike . When done one side at a time , the muffler hanger bracket is the jig to keep the pipe exits straight
Stock header pic I grabbed off the net . Never mind that it's a 1999 model , all the collectors were the same .
My modified header
<!--EDIT|mountainmotor
Reason for Edit: None given...|1143306727 -->