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Discussion Starter #1
I want to get a new exhaust for my lbz but I won't be making big power for another year or so. I dont want to short myself and get a 4 inch cat back because I will want the turbo back eventually. Ive heard it can cause more lag in lower rpms. Is this true? Is there any other red flags with this?
 

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Don't have an answer for you, but just earlier I stumbled on an old thread where a guy seemed to lose a little boost after doing a five inch straight pipe. That was the only post so I'm not sure what happened. Also saw one a while back where a guy had issues with boost or mpg's or something after putting in an aftermarket down pipe and went back to stock. I'm afraid I can't really help you otherwise. I'm new to this and been wondering pretty much the same thing.
 

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4in vs 5in will only change one thing-sound. There will be no performance difference between the two, and there should be no loss in performance by going from a stock exhaust to an aftermarket exhaust
 

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5" might help keep EGTs down a few degrees and make more noise, but if you tow a lot you will probably get tired of the exhaust drone.
 
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Discussion Starter #5
4in vs 5in will only change one thing-sound. There will be no performance difference between the two, and there should be no loss in performance by going from a stock exhaust to an aftermarket exhaust
Is there a benefit between cat back and turbo back? From my knowledge turbo back is the way to go. But im no pro. Also I can't seem to find a 4inch turbo back which is what I really would like.
 

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5" might help keep EGTs down a few degrees and make more noise, but if you tow a lot you will probably get tired of the exhaust drone.
I'm part owner in a construction company. I pull 15k + every single day. I just want a reliable 1200+ lb eventually. I feel intake and exhaust is the start. I already have the banks intake with the scoop. Huge difference by the way. I dont care too much about the sound. Im more looking for performance gains in the future.
 

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I don鈥檛 gave any links handy but I was just looking at all kinds of 4鈥 turbo back exhaust systems for my LBZ recently. My biggest issue with putting one on my truck is noise. I don鈥檛 want my truck really any louder than stock. A little more turbo noise is fine but I don鈥檛 want that straight pipe sound. I can literally tell if a truck driving by is a Duramax with a straight pipe because they are everywhere around where I live. I don鈥檛 want to listen to that while towing the wife鈥檚 camper for hours on end in the summer.
 

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If you were in @ChevyTech77 's position, I would say 4in with a muffler. My first LBZ (should have never gotten rid of that thing, dammit) was a crew/short with a 4in straight pipe downpipe back with a 3in downpipe. Wasn't real loud in the cab, but you could hear it. Wasn't overly loud out the tailpipe either. Two others after that were 5in with no muffler and 3in downpipe. They were loud- like loud all around. I like the sound of a 5in, but I was going to put a muffler in the last one until I sold it and he didn't want a muffler.
I always do a downpipe on the LBZ because it gets rid of the screech sound under heavy/wide open throttle. I HATE that sound, I cant tell you how much I hate that. They sound so much better through a 3in downpipe and full exhaust.
My LML now has a 5in with a muffler, and its just about perfect. Not too loud- both inside and out the tailpipe- but has a nice little rumble
 
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Discussion Starter #9
If you were in @ChevyTech77 's position, I would say 4in with a muffler. My first LBZ (should have never gotten rid of that thing, dammit) was a crew/short with a 4in straight pipe downpipe back with a 3in downpipe. Wasn't real loud in the cab, but you could hear it. Wasn't overly loud out the tailpipe either. Two others after that were 5in with no muffler and 3in downpipe. They were loud- like loud all around. I like the sound of a 5in, but I was going to put a muffler in the last one until I sold it and he didn't want a muffler.
I always do a downpipe on the LBZ because it gets rid of the screech sound under heavy/wide open throttle. I HATE that sound, I cant tell you how much I hate that. They sound so much better through a 3in downpipe and full exhaust.
My LML now has a 5in with a muffler, and its just about perfect. Not too loud- both inside and out the tailpipe- but has a nice little rumble
I don鈥檛 gave any links handy but I was just looking at all kinds of 4鈥 turbo back exhaust systems for my LBZ recently. My biggest issue with putting one on my truck is noise. I don鈥檛 want my truck really any louder than stock. A little more turbo noise is fine but I don鈥檛 want that straight pipe sound. I can literally tell if a truck driving by is a Duramax with a straight pipe because they are everywhere around where I live. I don鈥檛 want to listen to that while towing the wife鈥檚 camper for hours on end in the summer.
I dont care if its too loud or not
I don鈥檛 gave any links handy but I was just looking at all kinds of 4鈥 turbo back exhaust systems for my LBZ recently. My biggest issue with putting one on my truck is noise. I don鈥檛 want my truck really any louder than stock. A little more turbo noise is fine but I don鈥檛 want that straight pipe sound. I can literally tell if a truck driving by is a Duramax with a straight pipe because they are everywhere around where I live. I don鈥檛 want to listen to that while towing the wife鈥檚 camper for hours on end in the summer.
If you were in @ChevyTech77 's position, I would say 4in with a muffler. My first LBZ (should have never gotten rid of that thing, dammit) was a crew/short with a 4in straight pipe downpipe back with a 3in downpipe. Wasn't real loud in the cab, but you could hear it. Wasn't overly loud out the tailpipe either. Two others after that were 5in with no muffler and 3in downpipe. They were loud- like loud all around. I like the sound of a 5in, but I was going to put a muffler in the last one until I sold it and he didn't want a muffler.
I always do a downpipe on the LBZ because it gets rid of the screech sound under heavy/wide open throttle. I HATE that sound, I cant tell you how much I hate that. They sound so much better through a 3in downpipe and full exhaust.
My LML now has a 5in with a muffler, and its just about perfect. Not too loud- both inside and out the tailpipe- but has a nice little rumble
Where did you find the 5inch with the muffler?
 

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I have a local guy that is hooked up with a warehouse supplier/distribution company and can still get FloPro systems. Mine took like two and a half weeks to get here, and I just put the same kit on another truck and it took like five weeks to get here
 
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