[Ant]

I am in the process of building my side pipes, using 4.5" OD case, and 3" ID which is custom made stainless pert. I would like to think there is virtually no hp loss, although it will be noisy.
There will be a 2"OD insert for the road wrapped in sound deadening glass, this will really choke the hp and will hopefully get me past the 95db certification limit....