I just started using an old Enya 45CXL and for testing I used a # 7 Brian Eather pipe for a .60/65. So far so good and seems to work perfectly.

I do not have a smaller pipe, proper for a .45, to try and see what the difference would be. So I am wondering if there is any performance loss for using a much bigger pipe, or using a bigger pipe is better or it does not matter.

The other question I have about tune pipe is about the header performance.

Would  a lower header with a smoother curve make any significant difference in power?  

Martin