I want to thank everyone who chimed in. This has been very enlightening. For several reasons I am going to compromise. I don’t have the resources for extensive testing and no one here including my exhaust guy have the where with all to truly fine tune this system. I will go to the smaller pipe by transitioning down to that. On the end ports, I will start with an 8” x 1.625 pipe fit to the flange, this will transition into a 12 x 1.5” pipe and finally a 24 x 1.25” pipe. The siamesed ports will start with an 8 x 1.75” into a 12 x 1.625” and then a 24 x 1.5”. All this will go into a 3” x 10” collector and necked down to a 2” x 8” reducer. The Siamese pipe is approximately 140% the size of the end pipes or 70% / cylinder. Despite what has been said, both cylinders don’t empty at the same time and travelling at 1125’/sec, the tube should be virtually evacuated before the next charge arrives. This exhaust system is expected to work in the 3500 to 5000 RPM range. There is no need for clearance problems therefore the primaries will be a long gradual bend. If anyone sees major flaws with this compromise or has solutions that can work within the basic plan, please say so.
Thanks again
Warren
