What are the suggestions on diameter of piping used for an EJ22 swap?

I plan to use the stock headers. I will then start looking at doing a side-exit exhaust if it's not too laborous. Ideally, it will exit on the pass. side through the hole for the side-step blank (brat) with the piping being welded onto a sheet of metal that will cover the hole w/ two (or one?) ports from the piping to meet up w/.

 

Any better ideas? What size piping would be easiest, best on both high and low range performance, and sound good?

 

Edit :: What emissions parts should I retain on the exhaust system? I'm in MT so I'm most concerned w/ performance and quality of sound. Also, I'm trying to do this inexpensively, so if I buy anything it will be my buddy's used glasspack.

For the exhaust I would go with 2.5" just cause you said you are going to build the brat most likely for rally so you will need a free flowing exhaust.I think that thing will sing with a 2.5" exhaust.Should sound good coming out of the side.I would love to see some pics if you got em of your project.

It hasn't quite begun yet, I'm preping for finals week and collecting all the necessary parts in advance. Over my winter break I will be working on this, I'll try to get a digi-cam to borrow, but camera-phone pics might be the only thing I can get.

 

I was thinking 2.5" also. Should I just skip the muffler and cat.? Or should I at least run a glass pack? It might be too darn loud w/out anything.

Hey guys,

Not to rain on anyones parade, but I thought I read somewhere in a rulebook, that all exhaust must exit the rear of the vehicle. This may have been for WRC and not Rally Cross though, and I maybe totally mistaken. But it would really suck to go through all the work of building a great exhaust system and then find out you can't run the car in an event.

Just my $.02

NV

Some cars have stock side-exit, like the Dodge Viper for example.

 

You may be correct though. I plan to use flanges at a couple of points to allow easy removal when necessary. As for autocross, I've seen some cars run w/out any exhaust exit unless you consider under the car an exit.

 

And if they won't let me play w/ them, I'll start my own darn club and not let them race w/ me.

Admin's - Why Was This Post Moved To The Classifieds: WTB Forum From The Retrofitting Forum It Was Originially Posted In?

Not sure, but its going back