Exhaust Pipe Question.!

boomboom07 · February 3, 2008

Ok guys i tried doing a search on this and i got conflicting answers, so i think im more confused thant when i first started looking for answers. I want to put on an aftermarket exhaust on my 2007 silverado ext cab, 4.8. Well going into this, i thought that if you stuck the biggest piping under your truck the better. Well now I am not so sure now. From what im reading u can lose back pressure if u go to big, and lose low end torque. I don't want to do that. im assuming that the truck has 2.75 inch pipe. so would i be better off going with a 3 inch single outlet. or 2.5 dual outlet, 3 inch dual outlet. I wanna make more power. I also read that doing a cat back is pointless, is this true? should I just go ahead and slap a new muffler on with some tips and call it a day leaving my stock piping in place if i should happen to go with single outlet? I hope someone can clear this up for me. thank you in advance...

todoubled05 · February 3, 2008

Ok guys i tried doing a search on this and i got conflicting answers, so i think im more confused thant when i first started looking for answers. I want to put on an aftermarket exhaust on my 2007 silverado ext cab, 4.8. Well going into this, i thought that if you stuck the biggest piping under your truck the better. Well now I am not so sure now. From what im reading u can lose back pressure if u go to big, and lose low end torque. I don't want to do that. im assuming that the truck has 2.75 inch pipe. so would i be better off going with a 3 inch single outlet. or 2.5 dual outlet, 3 inch dual outlet. I wanna make more power. I also read that doing a cat back is pointless, is this true? should I just go ahead and slap a new muffler on with some tips and call it a day leaving my stock piping in place if i should happen to go with single outlet? I hope someone can clear this up for me. thank you in advance...

from what i hear this is true, about the pressure and small loss of low end torque..

IF u were to only replace the muffler, your more then likely not going to experince any preformance gains..

cat-backs systems work the best for preformance gains because you are able to control the rate restriction and direction of the flow of your exhaust. ultimatly cat-back systems are designed to increase hp/mpg/torque.

If i remeber correctly you wanted to change your system yourself?

IMO drop 400$ for a true dual cat-back flowmaster 40 sires setup with stright 3" pipes.

i have a 4.8 single in dual out flow 40 siers. and its awsome..

badmeds · February 3, 2008

Ok guys i tried doing a search on this and i got conflicting answers, so i think im more confused thant when i first started looking for answers. I want to put on an aftermarket exhaust on my 2007 silverado ext cab, 4.8. Well going into this, i thought that if you stuck the biggest piping under your truck the better. Well now I am not so sure now. From what im reading u can lose back pressure if u go to big, and lose low end torque. I don't want to do that. im assuming that the truck has 2.75 inch pipe. so would i be better off going with a 3 inch single outlet. or 2.5 dual outlet, 3 inch dual outlet. I wanna make more power. I also read that doing a cat back is pointless, is this true? should I just go ahead and slap a new muffler on with some tips and call it a day leaving my stock piping in place if i should happen to go with single outlet? I hope someone can clear this up for me. thank you in advance...

Mike,

I normally follow this advice when looking for an exhaust:

http://www.magnaflow.com/07techtips/faq/question10.asp

if you nose around some of the performance forums you will find additional information but most folks can follow the Magnaflow information and be fine. For me, the sound and nominal performance gains are important. I want my truck to breathe easier. More importantly, I don't like the look of a single exhaust tip so I have a single in dual out configuration. I would recommend a single 3 inch in and either a single 3 inch out or dual 2.5 inch out. The decision should be yours and base it as much on personal preference as anything we might have to add. Good luck with your decision.

Kevin

BurbanZ71 · February 3, 2008

Ok guys i tried doing a search on this and i got conflicting answers, so i think im more confused thant when i first started looking for answers. I want to put on an aftermarket exhaust on my 2007 silverado ext cab, 4.8. Well going into this, i thought that if you stuck the biggest piping under your truck the better. Well now I am not so sure now. From what im reading u can lose back pressure if u go to big, and lose low end torque. I don't want to do that. im assuming that the truck has 2.75 inch pipe. so would i be better off going with a 3 inch single outlet. or 2.5 dual outlet, 3 inch dual outlet. I wanna make more power. I also read that doing a cat back is pointless, is this true? should I just go ahead and slap a new muffler on with some tips and call it a day leaving my stock piping in place if i should happen to go with single outlet? I hope someone can clear this up for me. thank you in advance...

Mike,

I normally follow this advice when looking for an exhaust:

http://www.magnaflow.com/07techtips/faq/question10.asp

if you nose around some of the performance forums you will find additional information but most folks can follow the Magnaflow information and be fine. For me, the sound and nominal performance gains are important. I want my truck to breathe easier. More importantly, I don't like the look of a single exhaust tip so I have a single in dual out configuration. I would recommend a single 3 inch in and either a single 3 inch out or dual 2.5 inch out. The decision should be yours and base it as much on personal preference as anything we might have to add. Good luck with your decision.

Kevin

I agree with Kevin.

If you are looking to improve performance you need to take of the intake as well. Then add a PCM tune.

boomboom07 · February 3, 2008

Thanks guys. ur information is most helpful. I will be getting an intake when i get my tax return back, then the tune shortly there after. I think i might go to summit today and get me a muffler.I think im going to go with a magnflow 3 inch inlet/ 2.5 outlet.As far as the brand muffler I'm still not sure on which one to get maganflow, or flowmaster. I will have to make a decision once i get there.

ws6_guy · February 3, 2008

Larger pipe will flow more freely helping the engine a little more at high rpm range, and sounds real deep & bad ass, but you suffer low end torque, I have 3" true duals on my truck with Flowmasters and lost 0.4mpg cause it hurt my low end, but I went with the new Super 44 mufflers which flow much much better than those choker & baffled up 40s.

Thinner pipe will give you better back pressure increasing economy, and making it loud as f$%^ and it will pop when letting off the gas after going heavy into the throttle. If your going with a single exhaust, the best thing to do is go with a 3" intermediate pipe, going into a si/do ( single inlet dual outlet ) muffler with the outlets 2.5" so you can run them out and not have any issues with the spare tire, or if you prefer the single look, run an entire 3" system.

If your going to go with true duals, I would go with an entire 2.5" system with 3.5" thick tips.

And you have a wide variety of mufflers. Flowmaster is very popular, but are made of aluminized steel and will rust out eventually ( so you need to warranty your mufflers with them ) and the inner chamber design can be restrictive of exhaust flow ( & their called Flowmaster ) Your best bet is to go with a straight free flowing muffler like Borla, Corsa, Magnaflow, those are the top 3 in my book, they are constructed of stainless steel and will outlast all, but I'm a sucker for a deep toned & monster truck loud throttle sound so I went with Flowmaster.