The Tubo II is not a standard muffler. It looks standard from the outside but is a low restriction muffler. CherryBomb has designed some new mufflers that sound great and outflow the Blowmasters by a ton. I saw a live flow test between the 2. Blowmasters were 43% efficient and the comparable CBomb Pro was 78% efficient. Pretty much any Turbo muffler will perform the same just depends on how much $$ you want to spend.