Are there any side pipes for sale that DON'T eat HP?

[fordracing65]

One thing I noticed when I was at Kirkham was that the mild steel exhaust was almost twice as heavy as the stainless, plus I think stainless is a superior metal. I have heard a slight ring with some stainless but not with the Kirkham stainless. Don't know if any hp difference from the 2 metals...

[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....