Header length

[Obsessive R/C]

Could someone explain the theory behind different length headers...I know that they change the power band/ RPM range but I can't remember which is which.
Longer = more bottom end?? or vise versa??

[satoch]

Try a search on the web. I've seen great highly detailed articles before.

[Michowski]

short header will give more top end. long header will give more bottom end.