Header design

[Ferris]

I decided I have a slight issue with the header design, particularly the cross over pipe and where it's placed. Basically 1 and 2 merge and 3 and 4 merge and then the 1/2 and 3/4 combo merge right before the cat. The problem is they put the h pipe way up stream to tie 2 and 3 together. I think there would be better scavenging if the cross over pipe was placed after the 1/2 and 3/4 merge but before the final merge for the cat. Thoughts?

Better yet anyone know where I can get a set of used headers from?

 

[gr8eyes]

I wouldn't have a clue. I'll just trust Yamaha Engineers new what they were doing.

Glenn

 

[DefyInertia]

Have you identified a performance problem?

People part out crashed FZ6s all the time...I'm sure you could find some used headers without too much trouble. Check eBay and some of the other sportbike sites enough and you'll find some.
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VAPORMATIC REVIEW

 

[mikebike]

I too am curious about what issues the header design causes.

 

[Ferris]

No particular issue and it's more just theory. If I get a spare set of headers I'll dust off the MIG and see what I can do

 

[trailblazer87]

At those high RPM's wouldn't you want an X pipe nearer the front than the back?

I know the location is tuned to the motor on the V-8's we've built.

At the high engine speeds these bike motors reach the area where the pulses would reach the highest scavenging vacuum would be pretty small and probably ahead of where the header pipes come together. Besides wouldn't this negate the lower end torque the "tri-Y" headers inherently bring out? You may lose some "streetablility" for top end gains.

I need to crunch some numbers. Thanks for the headache:Flip:

 

[Ferris]

The beauty of bench tuning, like bench racing, is it's all just running of the mouth....

You're pretty spot on btw...

 

[dako81]

All the other bikes I have seen have only the inside 2 crossed over like ours. Maybe it's a conspiracy to rob us of our beloved power...

 

[poorwboy]

Its probably placed that way for bottem end torque, because it doesnt have a exup system.