New 3" exhaust with 2.5" Tailpipes

Advantage of the 3 over 2.5 is 18.85 extra sq inches of radiating surface per foot........... each. I think that works out to plus 20% or so.
Butno, the exhaust coming out the back of my full-length dual 3s is not cool enough to chill my sodaz
My entiire system, not including headers weighs about 70 odd pounds, with the mufflers a tic over half that.
How light can you make a dual 2.5 with 2.0 tail pipes and 3pass muffs? Could you make it 55? A savings of 15 pounds? What does that cost me in terms of performance?
I don't really care,lol; jus ruminating........
Once the engine gets up on the cam for 6 or 7 seconds at WOT, I could care less, those 3s are singing a happy song.