Exhaust question! Please Help!

[OverBoostinGST]

Ok well, I ordered my evo 3 o2 housing along with a megan racing 2.5 inch entrance and 3 inch out downpipe, my question is that I wanted to do a side exit exhaust on my car, I was wondering what catalytic converter to go with I found this site http://www.1aauto.com/1A/CatalyticConverterUniv/Mitsubishi/Eclipse, im going to have the cat then a 3inch side pipe routed out after the door, how loud is this thing going to be? If I got a smaller cat like (2 1/4 or 2 1/2) would it quiet it down? Or is it still going to be loud? Thanks Jesse P.S Some of the cats I was looking at on that site have air tubes, What exactly are these for? Are they needed or no?

 

[nightspeed87]

It will be loud ( similar to running open dp ) unless you add at least two sound resonators to it... My engine builder has a 3in dp and exhaust pipeing with no cat routed out the side behind the drivers door with a two tubed 3in muffler tip and it looks really good. The sound waves vibrate off of other ppls cars and scare them, its kinda funny. The reason he did it is because he stuck a 57trim on there and has a 2.3 stroker engine with race cams.
His car has one of the best sounds on a dsm Ive heard yet, but still slightly loud when you get on it, but its also because he doesnt have a cat. Heres his car, its a old picture, youll kinda be able to see his exhaust in this pic.

www.gearracing.com

Once you get there go to pictures and scroll down till you see a grey 1g with a fmic and side exhaust ok... and good luck with your set up !

 

[OverBoostinGST]

It will be loud ( similar to running open dp ) unless you add at least two sound resonators to it... My engine builder has a 3in dp and exhaust pipeing with no cat routed out the side behind the drivers door with a two tubed 3in muffler tip and it looks really good. The sound waves vibrate off of other ppls cars and scare them, its kinda funny. The reason he did it is because he stuck a 57trim on there and has a 2.3 stroker engine with race cams.
His car has one of the best sounds on a dsm Ive heard yet, but still slightly loud when you get on it, but its also because he doesnt have a cat. Heres his car, its a old picture, youll kinda be able to see his exhaust in this pic.

www.gearracing.com

Once you get there go to pictures and scroll down till you see a grey 1g with a fmic and side exhaust ok... and good luck with your set up !

That DSM is SICK!!!!