Hi Fellows,

What do you think, should I try to tune a Macs pipe (# 1190, TowHob LXZ563) for relatively higher speed
flight with OS.91FX on a propeller APC 12.5x12.5 ? Do you have some suggestions how long the header is
needed to be, or I better start cutting step by step ? Any data or comments could save me a great deal
of time. Thanks in advance,
Nick