I'm running into fitment issues, and I'm curious about something. Would I be able to run 4" to a cutout then split into dual 2" after then run into mufflers so I can run a quiet setup when I need. Most of the time and for performance I'll be rocking an open cutout. But I want the option, however I'm curious how small is TOO small.

This is all going to be on a 402ci with a s85 turbo.

 

my 5" is actually quieter than it was with my 4.8/radix with the 2.5" exhaust

 

Single 4" all the way out back should do it just fine. I run a 3" DP to a 4" from the bellhousing back. Flows more than plenty and sounds pretty badass if I do say so myself.

 

I'm going to run 4" all the way back, and have a cutout, but I want to split it in two, possible 2"? after the cutout so when its shut it runs through the two pipes/mufflers and out the back. Reason for the dual is the tip location. It's mainly a design and asthetics, but I want the duals to be functional. But I don't want an issue if I run dual 2"

But if I think about it I don't see why not right? Since single 4" is basically the same as 2 2", however I wanted to make sure it wasn't TOO small. I may even be able to split into dual 2.25"

 

I would just run 4in all the way to the muffler, then just branch off to two seperate pipes after the muffler. I did the exact same thing (but with 3") I wanted dual tips just for looks.... But the extra bends and the Y-pipe defienately changed the tone of the exhaust, it took out the deep blah sound, now it is just really defined...

 

2" is way too small. Run at least 2.5" through duals if not 3"

 

btw a single 4 will flow better than dual 2 and so on...surface area and restriction is higher.

 

Do a single 4" into dual 3" then... Make sure your Y collector flows well... You're talking about a lot of cubes and a lot of turbo.

 

I wouldn't go any smaller than 3" on the duals personally. I have 4" all the way back from the dp, and 3" back for the muffler for the wastegate and I have minimal room between my 4" and driveshaft. You may be able to fit 2 3" mufflers under there, but I don't know if it would be worth your trouble.

 

Just buy my 4" corsa setup from me. LOL