K guys, got a question for ya, and in asking it, I risk the possibility of looking stupid (again)...

What's the best size piping to have from the cat back to the muffler? I cut the second cat out, put 2.5 back to a flowmaster exhaust, and thought I was fine... yesterday some guy tells me that that's too big for the Lancer's engine and that for best performance I'd need to reduce that size to 2 1/4". Anyone have comments on this?

And while I'm at it... are there any advantages to a pre-built cat-back (advantages=better performance), rather than simply doing the piping myself?


Thanks

 

Buschur uses 2.5" piping without any trouble so you're more than likely safe going up to that width without any problems (loss of low end torque being the killer).

 

bought my muffler yesterday, i got a magnaflow one for 140, and am getting my custom catback 2.5 inch put on tomorrow, the guy at the muffler shop told me the same thing that id lose power but i trust buscher more than him.

 

after getting 2 different mufflers installed the guy at my local muffler shop reccomended that i go up to a 2.5 size(cat back) and man what a diffrence not only in sound but in performance too. the car used to have a high buzzing sound but now it has a nice deep tone to it . go for the 2.5 inch.

 

i'd say 2.25" but yea uhm you got to figure in you upcoming mods, the type of exhaust setup u got (the cound it will produce), the type of pipe u are using (press bent vs. mandrel) and cost.