Custom exhaust building...

[atutt]

Originally Posted by Odysseus

So Im a senior in highschool and for my senior project my shop teacher is going to help me fabricate an exhaust for my 240sx. I have a stock KA24E so I dont want it to be obnoxious and loud since I cant back anything up but I do want a nice solid aggressive sound.

I plan on using 2.5" tubing the whole way and ending with an HKS Hi-Power muffler in 60mm. That is something Im pretty set on since I really like the sound.

I dont know what to do before I get there though. Should I go catless? Or highflow cat? Can you point me in the direction of a good highflow cat?

Should I use a presilencer or resonator?

I plan on doing this manifold back. Im pretty sure my exhaust manifold is good but Ive been told I have an exhaust leak in my EGR tube.

If you guys could give me some insight and guidance Id really appreciate it. Thanks!

Stick with 2.5 all the way through. Get a high flow cat. But a real high flow cat. Do some serious research on high flow cats. You'll be surprised what you find. As some high flow cats flow worse than your OEM one does (ie, some of your fave name brands).

3'' on an N/A KA is overkill and is pretty useless. I personally run 2.25 ID from the manifold back. It's quiet running around town. A nice low grumble. But when I open it up it screams at me.

[soreballz]

Originally Posted by atutt

3'' on an N/A KA is overkill and is pretty useless.

Wrong. Wrong. Wrong. Wrong. Wrong. Wrong. Wrong.

Get the point yet? You're WRONG.

N/A KA's LOOOOOOVE 3 inch piping. This is FACT, and has been proven time and time again on dynos. Plus, the OP said he's gonna be swapping in an SR, and he doesn't want to re-do the exhaust.