KyleODaniel Posted November 19, 2013 Report Share Posted November 19, 2013 Would I be losing power if I ran a 3 in. exhaust all the way back from headers? I plan on doing a full exhaust with pacesetter lts, high flow cats, x-pipe and either corsa or borla mufflers, anybody with exhaust experience help me out on this one. Thanks- Kyle Quote Link to comment Share on other sites More sharing options...
JC03SS Posted November 19, 2013 Report Share Posted November 19, 2013 Anything over 2.5 is an overkill unless you are making about 600hp. 2.5 will flow plenty good. Your set up will be fine with 2.5. Unless your standing on it wide open all the time which I doubt. One of the fastest trucks here has stock SS pipes on it. Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted November 19, 2013 Report Share Posted November 19, 2013 What Jason said, 2.5" flows well. Quote Link to comment Share on other sites More sharing options...
KyleODaniel Posted November 19, 2013 Author Report Share Posted November 19, 2013 Anything over 2.5 is an overkill unless you are making about 600hp. 2.5 will flow plenty good. Your set up will be fine with 2.5. Unless your standing on it wide open all the time which I doubt. One of the fastest trucks here has stock SS pipes on it. So would this mean I should get a 2.5 in cats/ x-pipe/ and mufflers or if I were to get 3 in. and then just have the piping 2.5 in? or does it matter, sorry for the questions just new to the exhaust world. Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted November 19, 2013 Report Share Posted November 19, 2013 You can weld or get a adaptor to go from 2.5" to 3". my muffler and glasspacks are 2.75" and we're welded up. Quote Link to comment Share on other sites More sharing options...
JC03SS Posted November 19, 2013 Report Share Posted November 19, 2013 If it were me I'd do 2.5 when the exhaust shop puts it on all they have to to is open it just a hair and it will fit perfect. I have 2.5 everything but my cutouts. There 3". My dual in out magnaflow is 2.5. Mine is all custom.belive me it will flow more than enough. I have research exhaust for hours upon hours lol. Quote Link to comment Share on other sites More sharing options...
KyleODaniel Posted November 19, 2013 Author Report Share Posted November 19, 2013 Lol. Alright. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
JC03SS Posted November 19, 2013 Report Share Posted November 19, 2013 No prob hope your happy with the out come. Sounds like a nice setup Quote Link to comment Share on other sites More sharing options...
BLOWN SS/T Posted November 19, 2013 Report Share Posted November 19, 2013 You can do 3" at the collector and all the way to the x pipe and then neck it down to 2.5 or right before the x, or you can neck it down right after the collectors with a 3 bolt flange on each side. I have a 3.5 single pipe and love it. Quote Link to comment Share on other sites More sharing options...
jmgak47 Posted November 19, 2013 Report Share Posted November 19, 2013 Or you could do what I did... 3" from the collectors to where the factory flange/slip connecters were, replacing the factory 2.5" piping. Then use the factory 2.75" piping to 2.5" mufflers. IMO that will be the most efficient design that is simple... (it does have a H-Pipe but its hidden by the cross-member in the pics) Quote Link to comment Share on other sites More sharing options...
2003_SuperSport Posted November 20, 2013 Report Share Posted November 20, 2013 Or you could do what I did... 3" from the collectors to where the factory flange/slip connecters were, replacing the factory 2.5" piping. Then use the factory 2.75" piping to 2.5" mufflers. IMO that will be the most efficient design that is simple... (it does have a H-Pipe but its hidden by the cross-member in the pics) Almost identical setup as mine except I don't have a H-pipe I have a x-pipe about two feet before my two magnaflow mufflers setup like yours Quote Link to comment Share on other sites More sharing options...
GI.SS Posted November 20, 2013 Report Share Posted November 20, 2013 ok I know im gonna catch slack for this, but im gonna say it anyway. a 3" system is overkill but will produce the same power if not more. These LS engines love to breathe.PERIOD. The shop I deal with showed me straight up with dyno results why they would like to see me step up to a complete 3" instead of running my current 2.5". I do not have the dyno graphs nor do I have access to them. It showed a 5.3 truck that had a mild cam make 17 rwhp and 8 ft lb more by stepping up to the 3" system. The dyno pulls were an hr and a half on the same dyno not tweaking the tunes between pulls. With a forced induction system or nitrous system a 3" will only help and not hurt as well. SO go ahead and flag me and yada yada yada... but I have seen this for myself and will be upgrading come spring. Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted November 21, 2013 Report Share Posted November 21, 2013 ok I know im gonna catch slack for this, but im gonna say it anyway. a 3" system is overkill but will produce the same power if not more. These LS engines love to breathe.PERIOD. The shop I deal with showed me straight up with dyno results why they would like to see me step up to a complete 3" instead of running my current 2.5". I do not have the dyno graphs nor do I have access to them. It showed a 5.3 truck that had a mild cam make 17 rwhp and 8 ft lb more by stepping up to the 3" system. The dyno pulls were an hr and a half on the same dyno not tweaking the tunes between pulls. With a forced induction system or nitrous system a 3" will only help and not hurt as well. SO go ahead and flag me and yada yada yada... but I have seen this for myself and will be upgrading come spring. Yes that maybe true however what did it do to the torque curve? Everyone gets hung up on a peak hp number, but forget it takes torque to get these heavy pigs moving. Im not flaggin you at all. I would run a 3" exhaust as well but not for the tiny peak HP gain. I would run it for the simple fact that it will more than likely be the last exhaust you put on the truck as 600-700hp isn't all that hard to make. Now 1000 is harder and that is about where the 3" stuff will be a hindrance. Quote Link to comment Share on other sites More sharing options...
GI.SS Posted November 21, 2013 Report Share Posted November 21, 2013 from what i remember the curve stayed almost the same as it was with the 2.5" just made a tiny bit (1-2) more in the lower rpms but made much 5+ above 4500 rpms. And that is exactly my thinking as well. I wouldnt run it to squeeze a tiny bit more out of it, but as it would be the last exhaust I would have to buy. Esp with the bug where whatever power you make isnt enough. Plenty of room to grow, which I know most will be doing anyway. Quote Link to comment Share on other sites More sharing options...
coal miner Posted November 24, 2013 Report Share Posted November 24, 2013 3 inch will kill your torque!! Trust me been there done that. It will run like a trud. Quote Link to comment Share on other sites More sharing options...
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