Change in exhaust diameter...
 

Have an exhaust question...I recently had a downpipe fabbed up, and it was gonna be hard to fit in a 3" pipe so went with the 2.5"...As of now the downpipe just consists of the flange with 2.5" piping, there are 2 O2 bungs and then it just ends in straight 2.5" pipe...Is there any way I can go to a bigger diameter(3" specifically) pipe farther down the exhaust say after a hi-flow cat...I looked for a converter that was maybe 2.5inlet/3.0outlet, but I didn't see any made that way...Is there anyway to change pipe diameter or am i just gonna have to go 2.5" all the way back...Just think 2.5" might be a little bit of a restriction, I'll be running a t3/t4 .50 trim on 2.5L 4banger...Let me know if you have any suggestions...

Re: Change in exhaust diameter...
 

depends on the hp u r shooting for, i ran 2.5 for a while and noticed a few hp after the 3" but a bigger difference in spool time, many be look for a 2.5 -3" transistion racing solutions has them for 14.99 put that on as far up the dp as possible ie right after the bend under the oil pan hope this helps alittle

Re: Change in exhaust diameter...
 

yes, use a 20 doller pipe expander

Re: Change in exhaust diameter...
 

rear cat off of a 1987-1996 f150/f250 4.9l is 3" in/out, 2.5" out/in

and i happen to have one

Re: Change in exhaust diameter...
 

^^^^ what kind of shape is it in??(probaly would ream it out anyway)...and would you maybe be interested in selling it??