TBH When I switched to SC there was no major volume changes in the exhaust and I have a set of noisy duals an a decat! Some have reported extra volume, but personally I'd put the SC on if you can't live with the exhaust then change it.
One thing I can say is I recently fitted a 4-2-1 manifold and it quietened the exhaust, but I think this has more to do with the duals than th SC!
One thing I can say is I recently fitted a 4-2-1 manifold and it quietened the exhaust, but I think this has more to do with the duals than th SC!