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DIY exhaust questions

2K views 14 replies 6 participants last post by  texazranger07 
#1 ·
i posted this in another thread but i wasnt paying attention and i figured it might get some better responses here.

ok i've been looking at doing this for quite a while. im going to hold off on the opened up downpipe for now until spring/summer rolls around. i can get a 10' 4" pipe for about 77 or so bux from a local store. only problem is i'm planning on doing a side dump in front of the back tire. i haven't measured it yet but i know i don't need 10'. the longest sizes they do otherwise is 3' lengths. i also found pipes on line i can order by the foot. so here's the main question:

is the stock downpipe, coming rite before cat 3.5" or 3". i found the universal MBRP adapters online as well at ADAPTERS . id either go with 4" or just play 3.5". id like to get this done as soon as possible because ive been putting it off for far too long. i just cut off my muffler and back yesterday, its a little deeper but no big difference as im guessing the cat makes a big difference as well so i want that gone.

o yea heres the link with the exhaust tubing. TUBING


what would you guys do with that given info???
 
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#4 ·
i would do that...except i have a crew cab..so thatd be coming out rite at the side of my cab, id much rather have it at the back in front of the tire...im just gonna heat it and bend it as needed. i just wanna get all the diameters rite and need some people to confirm what i should do ya know?
 
#6 ·
if you cut it before the flange at the end of the down pipe its actually 3 inches, I did the same thing and ended up having to crush the 3.5- 4 adapter a lil to get it to fit. The cat is 3.5 - 3.5 but the down pipe is 3 at the flange so if you have some pipe after the flange cut it there or get a 3-4 adapter.

ps, best bet is to get under the truck and measure, wish I'd done that lol.
 
#8 ·
I guess what youre saying is that two pieces of pipe that are the same OD wont go slip together... right, so when you buy the adapters make sure to get the ones that have the bell already stretched out to slide over, they are about twenty bucks at my local truck shop.
 
#10 ·
:hehe: well I dont think I can, I went into the truck shop with a 4" in mind and did the 5" instead, guess it wouldn't be much more to do six lol.

I do think you may lose some of the tone that you often relate to a good sounding diesel, the 7.3l doesn't sound as good to me with huge pipe like that, but it will certainly be loud and turn heads...
 
#13 ·
i have a 2 piece downpipe in my truck, alomost impossible to get a one piece in.
2nd mine comes out in front of the back tire, my dp is 3.5" so i put a 3.5-4" adapter on the dp, its 4" to where the cab meets the bed, then it goes into a 4"-5" adapter then a 5" 45, then just a short section of 5" to bring it out beyond the tire a little, its not hard to do, but in your case i would cut the stock exhaust off between the cat and dp then get a 3.5"-whatever-you-want adapter then go from there, also, i had a 5" pipe clam, not band clamp, welded to the frame to hold the exhaust, you can see what the truck looks like in my sig, hope this helps:thumb:
 
#15 ·
actually i havent been on the forum for some time. i remember seeing your truck and honestly thats what spurred me to want to do this. that and its just cheaper and easier than running it a traditional way. not many people around where i live have it, in fact i think only one person ive seen. i ordered that downpipe off ebay a few mins ago, so i think for now im gonna run it from 3 off the dp to just a 4ft length of 4". ill see what that does for me but after that if i could find someone to make me a 4 to 6 adapter i can run it like that after, if not ill just do the 5. damn crewcabs take about 8 feet of pipe to get from the dp to the back tire haha
 
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