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4 inch exhaust ?

jake666

Full Member
Joined
Feb 10, 2008
Messages
130
Location
eau claire wi
iv finly got my 2500 lifted and now to tackle the exhaust . iv spent way to much time laying under the hoist lookn at the bottom maken plans . i dont want duals . must be gettn old lol .. im gona remove some cats .. yeah yeah  i know . but with 200 k on my truck theres not much left to remove anyhow from them lol plus gona get rid of that flattened pipe thats run above the tbar crossmember .so im thinkn of y ing the 3 inch pipes into a single 4 pipe  to a single 4 inch muffler to a d-max 4 inch tail pipe .. im just wondern if the single 4 is over kill for the 8.1 but a single 3 just seems way to small ?
 
The factory set up is 2 2.75 inch pipes. So a single 3 inch is too small. 4 inch is for the diesels, you can try it. If you get rid of the cats you may have to put sims in if the 02 sensors are behind the cats. if you don't have 02 sensors behind the cats then you can do the 4 inch. price it out and let us know.

Avalon
 
nope no post cat o2s for me .. I'm gonna try it  got a tail pipe coming on Tue and a muffler . found a 4 inch stainless muffler straight through louvered core 30 inch's long  . hopefully will be quiet . for 40 bucks tail pipe cost me 68. . once i get those i can see build a 3 into one 4inch y that will fit and put the pipe where i need it . since I'm lifted the t bar cross member isn't in the way still gonna be a bit tight
 
I am just wondering do you care about gas mileage LOL. Really what is your goal more power. ???
 
I gutted my converters, removed stock muffler and tailpipe, fitted a 2-3" to single 4" Y-pipe, welded on the Flowmaster 40 series 4" diesel muffler, and used the MBRP tailpipe from my old duramax.  Everything fit great with a little cutting and welding.  Sound is absolutely amazing considering how anemic the stock cam is.  Sounds how a big block should and has turned many heads.  Reasonably loud but very minimal droning in the cab.  Flows really nice.
 
did mine i built a y forward of the trans crossmember 3 to 4 inch pipe . since I'm lifted the torsion crossmember isn't in the way . to a 4 inch Flo pro  straight through muffler  30 inch case .used a dynomax tail pipe for dodge cummins . there so much cheaper then the duramax pipe and their almost the same . i did add a 45 bend to the end of the pipe so it exited in the factory spot other then that is was simple . even reused all the factory hanger locations . just welded new bars to the new pipe . sounds pretty good . drones a bit in the cab  . if i get sick of it ill change out the muffler to not a straight through type . but for the 30 bucks i paided for it i couldn't say no lol . funny thing is it doesn't even look like its that big of a pipe lol
 
I'm doing the same setup and I have heard drone is a Female Dog. I did a search on performance trucks.net and the answer is right there
 
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