on spintechs website they advertise that the sportsman splitcase (aka crossflow) muffler for our cars flows 175cfm @5" water. the single in/out ones flow less at 170cfm.

i thought most tests were made at like 20.4" water and to my understanding the more " of water means more flow. so are they basically saying that their mufflers cant flow more than a measley 5" pressure drop? i called them one day and asked if my 3" spintech crossflow muffler was hurting me as far as power. and his response was well you could have gone to a 3.5" system and that would have been better. i asked him how much the mufflers flowed and all he would say is "its enough" that right there made me want to throw the

flag. so if my bolton lt1 needs a 3.5" system from spintech to flow properly then i know it aint enough for these big hp cars. all i know is that my car revs a hell of alot quicker with the cutout open than closed. and at higher speeds it really starts struggling with the cutout closed. im seriously considering taking a 2.5" dynomax ultraflow muffler and putting in the stock location with a turndown tip so it cant be seen. even the 2.5" muffler flows like 1100cfm. plenty for me and for when i build it.