just went outside to look in the tip. are you referring to where the tip starts at the muffer?thats like 1 1/2" of where its smaller. im pretty sure that wouldnt make a difference. if it did your talking a very small amount. my xt made the usuall vf power numbers at topspeed.i wasnt happy with my tune, but thats a different story there
the thing with maddad is you have to contact rich, he doesnt always answer the phone, thats why i have a invidia downpipe and not a madad, he would never answer. im glad i was able to get the catback at least. the welds on mine look good, at least where i could see. never really looked up in the muffler till i saw your pic.