Straight header vs. stepped header on a 604

[dirt0]

Just wondering if anyone has ever done any testing with this or dyno testing to see which is better.

[brad hibbard]

We learned early in the crate program that a stepped tube would gives us a good blend of upper and lower end power
in general discussion the smaller the primary tube the more low end TQ.
and larger primary tubes increase the upper power band
However starting out with a small primary and then increasing size down stream (Step Tube) showed an increase in the upper band without damaging the lower end power

hope that helps
Brad

https://www.race-1.com

[dirt0]

Thanks Brad