So I'm going for that deep low pitch sound (aren't we all). (I would love to get the sound you can only get from a STI), Here is what my system will be and tell me what you think, cause its so hard to judge what an exhaust component will sound like until it is installed.

Header: Maintec 4-2-1

CAT: High Flow Cat (Magnaflow)

Piping: 2.5" piping

Resonator: High flow resonator, or a glass pack? (I do live in California so emission laws are strict.)

Muffler: HKS Carbon Turbo Muffler (75mm inlet, 120mm outlet.)

What do you think?

 

If the laws are strict, how are you going to get away with removing the primary cat?

 

Magnaflow makes a high flor cat that passes Emission/ OBD2 EPA/CARB compliant. They cost an extra 180$ when compared to a reg. high flow cat that runs around I think like 80$-100$

 

http://www.rdtiburon.com/index.php?showtop...=custom+exhaust

Reading through that should help a little ... it really depends how loud you want to go man.. "deep low sound" isn't very descriptive..

From my experience, that setup is going to be LOUD. It will sound good, low, deep, smooth, all the things you say you want, but it IS going to be loud. When you have passengers in the car on the highway, you will not be able to hold a conversation at a normal talking level, you'll have to talk louder, not yelling, but not normal either. I guess that's the best way to describe it?

Hope that helped..

 

unless your boosted you dont need the turbo muffler...get a magnaflow muffler(with no silencer) sounds amazing

 

homey, welcome back man!

2.5" is a little big for NA, unless you are heavily modded.

If you are crush bent then 2.5" would be ok. It will be quite loud though, especially with a turbo muffler.
Actually, you live in California? Doesn't everything have to be CARB approved? Because none of this stuff will be.

 

Ya I'm still debating about the 2.5" piping. and ya the high flow cat is the only thing that has to be carb approved other than that you just need to make sure all your O2 sensors are hooked up. I've used magnaflow mufflers in the past I think I might use one again.
Thank

 

I was told that if the piping is too big and the muffler is to small u will get a buzzing noise. Another problem with overly sized piping is the loss of back pressure. I have 4-2-1 headers, standard cat(no need for hi flow unless its turbo), a hot dog and a straight thru glass packed muffler. The sound is deep. I have to give u a sample. The Factory piping size is right. 2 inches in diameter. I was told by many places to stick to 2 inch because i would loose the back pressure which would result in loss of midrange torque. You won't notice the difference straight away but after a couple of weeks you will.

 

people people people.. backpressure is BAD! No matter what people say, backpressure robs power.

what they really mean is that too large an exhaust pipe allows the exhaust pulses to "stall" because they expand too much to keep up their pressure wave that pulls them out the tail pipe.. in essence, going TOO large can result in even more backpressure than too small.

for a mild NA setup, I would go with 2.25 inch, mandrel bent.. I do not care what people say about 2.5 crush bends being the same, they are not. The crushes cause turbulance, which breaks up the pressure wave and slows things down

 

What about the header flex downpipe? All headers come with that pipe being 2", is that a bottleneck if the rest of the exhaust is 2.25 or 2.5? Anybody with a custom-made 2.5" or 2.25" downpipe?