I'm puting at Tecate motor in a Mojave chassis and I need to fabricate a pipe. Does anybody know any calculations to use to make a custom expansion chamber. Examples of diameter and lenght etc.

 

You'll have to know some of your engine characteristics. TSR Software offers a tuned pipe program that takes your input and then formulates the proper cone dimensions for you. Air Cone in Las Vegas will then roll cones to your provided spec's. You'll need to know your compression ratios (CCR & UCCR) and port timings at a minimum to design and fabricate a new pipe.

www.tsrsoftware.com

 

Try looking on macdizzy.com, I have heard nothing but good things about this guy.