ok so i searched and as we all know, it's not the best so here it goes. I just bought a brand new 13' Sierra and am looking for a good exhaust system for it. Does anyone have dyno sheets that show which exhaust system produces the most power for the 5.3? Which system has the best/loudest note?
I LOVE a loud exhaust on trucks but it usually comes with either bad drone or bad performance. Furthermore, which system is your best bang for your buck? In many cases ( as it is in the motocross industry ) you could spend $1200 on an exhaust system and end up with absolutely no power gains but just a better note. If I buy a $800 exhaust system, will I have been happier with a $200 muffler and a cold air intake? I know that most of the time, the difference between a muffler and a full exhaust is only 2hp, which is not worth an extra $600 to me. Any help?

 

Long Tube Headers.... Pacesetter, Kooks or ARH
and if your an emission tested area you'll want the Kooks cause they offer a catted y pipe
match it up to the factory exhaust which is already 2.75" and pick whatever muffler you want except flowmaster

I may be wrong but I saw somewhere LT's are dyno proven 21RWHP

 

To be honest man, long tubes will void my warranty (my truck only has 323 miles on it), and my truck is too new to void the warranty. I was told by my dealer that anything cat-back won't void the warranty.

 

Get the kind of exhaust with a turbo in the middle somewhere.

 

so pick a muffler that you want, get an Airaid MIT and ride like that for a bit. you'll pick up some gains and be ready for when you do get long tubes

 

Swap out to a 6.2 catback, weld up a QTP electric exhaust cutout right before the muffler and done. That setup will give you power and sound open or closed.

 

your truck has three cats i would delete the third cat and replace your muffler with a short glasspack and turndown before axle.

 

thats not a 3rd cat, its just a resonator
but ya remove it just the same!

 

I do have lt's but over the last 5 years I've had regular 40 series flowmaster,super 44 series FlowmAster, borla xr-1 oval, dynomax ultraflo and magnaflow. I've had them dumped, just under bed with no turndown and several different variations of tailpipes. I always liked a tailpipe to help with any drone or cab vibration but like the no tailpipe cleaner look. Final setup resulted in the oval 14" case 3" id Magnaflow with a single tailpipe over the rear axle and brought back then dumped right in front of the bumper. Love the sound. Great at idle screams at wot but no interior resonance. Heck at 60 mph I can still listen to the radio on volume 4-5! LOL just my .02.

 

Ok maybe i should rephrase my question. Is getting a full cat back system worth the extra money (in HP numbers) over keeping the stock 2.75" system with a straight through muffler? It seems like that latter would be cheaper and allow for more mods. No? But i know a magnaflow exhaust will gain about 11hp on this truck. Will a straight through / very open muffler give me close to that? I cant image that .25 inches more in diameter will make that big of a difference.