chevy619

I have a 01 silverado z71 and would like some opinions on what i should run for my exhaust. I have talked to country_09 some on this and he suggested i go with a dynomax bullet over a flowmaster because they have horrible flow even worse then the stock muffler in some cases from what i have saw online. From the clips i have listened to on youtube the bullet seems to sound nice but here is were my question really comes in. I know 3 of my buddies with these trucks that have just cut the muffler out and put a piece of pipe in its place but it made the truck run rougher, seemed as if they lost some power and it even decreased there gas mileage overall it effected the truck in a negative way all together. Im not sure why this is? If there wasnt enough backpressure in the system due to the muffler being gone. Which makes me think the bullet would give me the same effect since its just a straight through glasspack more or less that will not mantain any backpressure. Im worried putting the Bullet on will give me the same results all my buddies had when just cutting the muffler out and piping it into the tailpipe. So im just not sure what to do for my exhaust set up anymore and looking for idea, opinions any information on this and why the no muffler set up was causing all 3 trucks to run like that. I plan on keeping my cats and just putting the aftermarket muffler in and y'ing duals out the back of the truck.

nkh34

i have a honda civic that the muffler fell off and it ran like garbage i was 16 and didnt have money for a nice exhaust system so i had a glass pack welded in and thought it wouldnt do much for my back preasure but im not sure how but it ran better then before a little zippier too. it worked fine on my car but it could be different on a truck. let me know what you decide on and how it is i just had to cut mine off so im on the hunt too

Cpb200

ok this is simple its not back preasure its exhaust volacity look at any new tech site and it will explain the same and if you get the consept it makes sence basicly to big of a pipe would not make enough "preasure" to puch the gases through the exhaust and out making it get trapped and cause problems the simple fix is use the right size pipe so for a 5.3 (example) a single 3 inch in to a y pipe after a bullet to 2.5 would help this effect also stock cats would add to this effect so the reason people loss the low end is becuase of this somehting i took into consideradtion when i did my exhaust on my 2500 but adding a bullet would not affect your low end with stock cats on as long as its no bigger than 3inch on a single in/out configuration

cleveland63b

backpressure is a hugely mistaken thing, the "technical" term for what cpb was talking about is exhaust scavenging or the simply put "chimney" effect. Too open or free flowing could hurt performance just as bad if not worse than a clog hence the reasoning behind the price tag on most exhaust kits. You're not paying for the material you're paying for the engineering and in some cases name

jgray152

I'm in the same boat. 1997 5.7l here. I am also thinking of the design in terms of single in single out or single in dual out or dual in single out....true dual I believe would b the wrong idea.

I'm leaning toward dual in and single out of muffler to create more scavenging in the rear of the muffler to help pull the exhaust through.

now I believe the scavenging effect gets even more technical. restriction with a smaller pipe would cause scavenging.but if you have a muffler causing additiinal restriction it couldng make th exhaust flow more turbulant loosing that negitive preasure behing the echaust pulse which creates the scavenging effect to my belief.

so that is my theory. I think a muffler with good flow direction with a single out would work best but I really have no idea.

correct me if I'm wrong bout anything

acer9876

do you know of any kits for the 97 5.7?
im looking for a cheap kit of pipes. with or without cats and muffler, i want dual with x pipe.
im having a problem finding something less than 250. im going to run different cats, and glasspacks. just need cheap pipes.

Cpb200

you can always build you a custom exhaust to meet what you need my truck is a 6.0 what im planning on doining is running the stock pipe to the muffler (dual in single out stock) then cut the muffler off to two muffler and have the pipe size down the 2.5 for exhaust volacity and have an h-pipe put in for equal preasure in the pipes and better low end tq although the x pipe would make a better vaccum affect just not the same tq numbers that im looking for

x-pipe great all around good flow and power evens out exhaust tone more high end power and a smooth exhaust tone

h-pipe equals out the preasure in both pipes on duals good for low end tq (up to 3000 rpm) and has a deeper raw tone

jgray152

Nothing cheap. Im thinking possibly the best exhaust is to use is the stock piping sizing/configuration with a different muffler and possibly new or better cats. A new muffler in general will help to slightly open the exhaust. Unless you modified the engine to push a lot more power I don't see a reason why to go with larger piping or to go true dual.

I have to look again but I think the muffler on my, well soon to be my truck is dual in and single out. Has to be a reason why GM made the exhaust that way.

I believe everything else is for looks and sound on a stock motor. Im going for HP/Torque. Any muffler I get will be slightly louder than stock so not worried about trying to find noise.

chevy619

So from what your saying replacing the stock muffler with the bullet then running the why pipe out with 2.5" pipe will help cure this problem I am talking about? Although my buddy ran the same setup minus the bullet instead he just had a pipe and it was cauing his truck to run weird, loose power and even gas mileage? The fact that the bullet is basically a straight through pipe, not much more then a standard piece of pipe is why i ask if it will have similiar problems.

cleveland63b

true duals isnt always bad..i run a custom true dual setup on my 92 but its only 2.25" tubing