Side Pipes

[RonNichols]

Originally Posted by greg schroeder

I guess there are many variables.

I ended up 3 jet sizes higher with side pipe change.

There wasn't any other variables like new carb or previous carb was not adjusted?

R

[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"?

[Rare Iron]

Originally Posted by RonNichols

I've had my side pipes off quite a few times over the past year. I used to use stainless fasteners until recently. It seems that I have run into shoddy fasteners that once torqued, would seize, and then I simply just unscrewed them into two broken pieces. The box had an origin sticker that said "made in China" so I just figured I would change. I have since replaced the fasteners with grade 8 bolts with a serated flanged nut seated onto washers on both sides of the flange. After several months of heat cycling, its still tight.

R

I always liked the idea of using stainless bolts for exhaust applications too, until I learned that you cannot harden stainless. Grade 8 is the only way to go, or you are going to risk breaking off bolts inside your cylinder head or other places.