[Ant]

With every engine being different ie FE427, and SBF in various states of tune, one design isnt going to suit all applications, but most seem to go 3" ID perforated tubing, and 20-22" and some going up to 4.5" case size for a wee bit of extra muffling!

I am about to make my mufflers for my more race engine application, and wonder if I need to go up to 3.5" internal perf tube for a 600+ bhp running 7000rpm! Maybe if I was running the other type of tube which has spiral restrictions or little entries so the gas can expand into the outer case then 3.5"?