I know it will be loud, but I would like to quiet it down as much as I can along without having a drone if possible.. I feel like my RB is to restricting. I just don't want to wake up the ppl from 2 blocks away with just starting the car lol.

I was thinking on magnaflow mid and catback.

Then I saw a borla also, but I can't seem to find much else for a 4inch besides those 2.

I have no clue how either sound or perform.

Anyone have similar setups? Maybe with audio? Or a different set up that's even better?

 

I had a production 3.5" on my FC and then later re-fabbed it myself with v-bands and a new downpipe area and muffler.

The large diameter exhaust is always low frequency loud that shakes houses. You can get it quieter, but the note always seems to set everything to shaking.

It can also limit your low where he exhaust passes by the differential or at the least become the first thing road debris hits.

For my FD I am going to grab a couple of the Ebay 3" turbo back exahausts, a Vibrant dual 3" inlet muffler and a pipe expander (and do slip-fit instead of V-band) and make a dual 3" turbo back.

Cheaper, more ground clearance, more exhaust area, easy to fab and light.

That is the plan anyways...

 

Magnaflow sounds great. Borla has more rasp, does less of a job at stopping the resonation

 

Im using 3 magnaflow 4" mufflers on my BP 13b-rew and it's quite enough. Bellow 96 db at 4500 rpm for sound check on trackdays. Im using the oval versions. 2 linked together allong with the tranny and the last one at the back with thr end turnd down.

Sounds realy good and is not too bad. More of a deep rumble then a high pitch that you get from 3" exhaust.

 

Hey got any pictures or audio of that? I mean if i can fit 2 magnaflow under the car and the magnaflow catback. I guess it should be better than not having any. Which ones do you have?

 

after some study, there are two principals at work here.

the first is the pitch, the 654cc chamber firing every 180 degrees gives a basic pitch, you notice that sounds different than a 3 rotor, which is the same chamber, but 120 degrees, or say a 5.3 LS engine, which has 662cc chambers every 90 degrees*. when you put this in a pipe, the pipe size and length will give you the pitch, like a pipe organ. 4" pipe is a low note, you're kind of stuck there.

the second part is that noise is the difference between the high pressure exhaust gas, and the low pressure area after it, think of a speaker, or a sine wave or something. noise is the difference in pressure. most mufflers function by dampening the high the high, and you see some cars (stock FD does this) are silent at high rpm/full throttle because the exhaust has limited the flow enough that at the muffler tip its just a constant flow, which is quiet.

what seems to work ok, is to make whatever exhaust you need up to the muffler tip, and then either run a small tip, or tips. i have a 12A P port, and the best way to make it quiet is a 2x2" tip, works way better than adding mufflers or anything else. impact on power is small enough that on the street its not noticeable. with the tip installed its actually quieter than my turbo FC.

*an american v8, being weird, fires 2 cylinders next to each other, so the distinctive sound is you hearing 6, 662cc chambers and one 1300cc chamber.