Home built exhaust and mufflers for my bobber

[1987notchback]

hey guys have some questions on the exhaust that i am buiding. the exhaust pipes are 1 5/8" OD and 1 1/2" ID. my problem is i want to use small mufflers to quiet it down but i want to build them within the pipes so they still have the straight pipe look. i have made a few test pieces to see what will work. my main question is how small/large should i keep the smallest id on the muffler without restricting the exhaust to much. i will be using fiberglass muffler baffling/packing and not to state the obvious but the smaller the id on the exhaust is the more packing i can use and the less the larger it can be. so what size id should i try to stay with? thanks mike

 

[kvanderploeg]

I threw together a pair of baffles this past weekend for my Curved Drag pipes from gordonscott. I just used a copper reducer into a smaller coupler and soldered them together. In the smaller end, I welded a washer to a 10-32 screw and stuck that inside the baffle at at 45° angle. I may still drill a few more holes where the reducer is to flow more air, but my main focus was to quiet it down enough for state inspection. I'll try to get some pics tonight when I get home.

Kent

 

[KJ790]

You would be more than fine with 1" diameter, you might be alright with 3/4" diameter cores. Another thing you can do is to step your headers to the next size pipe so that from the outside it will just look like stepped straight pipes, but this will give you a little more diameter on the inside for packing.

 

[1987notchback]

cool thanks for the info guys. i got some 1" id pipe and am making glass packs out of them. it will be a tight fit with one layer of fiberglass packing but should do the trick. thanks mike