ok i have a 5.3 with bolt ons and no cats and a single in and out flow....the people at my exhaust shop are telling me not to put duals on it because it will run like crap but i want to any ideas will it really run bad and loose all botton end? i was wanting to run dual magnaflows dumped

 

To be honest it'll flow just a little better than the flowmaster, but unless you have longtube headers I wouldn't do it because you won't notice any difference. A 3" single outlet exhaust is well enough for 400+hp n/a motors. Unless you're planning on boost anytime soon just keep the flowmaster or swap out the flowmaster for a magnaflow if you just don't like the flowmaster sound.

 

btw, i have the pacesetter LT's and the 3" offroad y pipe. I have the cats welded into the y pipe, but after that I just have it dumped (single 3") under the cab. When I get tired of it being too loud I just bolt my super 40 series flowmaster back on to the exhaust. On the dyno it shouldn't make more than a 2-3 hp difference with my muffler on there. I was thinkin about true duals at first, but I'm not going for the cool sound factor. Just stick with a single 3"in 3"out muffler until you do some serious mods.

 

If you're more performance-oriented, stay with a single 3" exhaust. If you're more interested in the cool factor, the true duals will get you some of that, but I predict you won't like the performance.

 

duals for sound, single for performance.. or get duals with e cutouts? i dunno just a thought.

 

they'll both perform the same pretty much, but duals is just overkill IMO.