Which exhaust is the quietest?
 

I want to change my exhaust again (have 2.5" crush-bent w/ cat, resonator, and thermal muffler) but it's way too loud. Anyone knows of any good turbo exhaust which is also very quiet?

Keep in mind that your current exhaust will get much more quiet once you get the turbo on.

my dynomax super turbo (~$50 at advance auto parts) 2.25" is reasonable on my NA car with the high flow cat and 2.25" cat-back. I imagine the 2.5" version would sounds good without being too loud on a turbo car.

i hope so. right now it gets extremely raspy past 4k rpm and its WAY too loud even at idle. i still have jrsc in it right now.

you cant even hear my exhaust over the turbo :bigtu:

haha! this is exactly what im trying to avoid. california police is very strict and i really dont want to see my car being crashed along with some shitty hondas :/

im going for a sleeper look :)

must suck for you guys...i dont know what i would do if i saw my car being crushed, and its not even turbo yet...i think id cry...seriously
as far as your question, ill ask a friend of mine, his car looks stock but is pushing almost 300 rwhp on 15 psi...exhaust very quiet, looks stock too and ill let you know

you're trying to advoid an exhaust that sounds equal to stock? cause that's what I'm saying mine sounds like.

whaaamx5: please ask him what exhaust he is running
Braineack: im trying to avoid any sounds at all that would point out my "non-stockness" to cops. which exhaust are you running?

It will quiet down a LOT when the turbo goes on, believe me. I don't have a muffler on either car and neither is all that loud.

hopefully that freaking rasp will go away too! cant stand it. feels like im driving a honda civic or something :/
i even stopped driving my miata since i got that exhaust!

Until my Enthuza and other components go on mine, the Miata is just Greddy DP > stock cat > mufflerless stock piping. Before the turbo it was the same, and it was LOUD AS SHIT and very raspy. Now that the turbo is on it is very quiet.

ive got 2.5"dp, 3" cat, 3" catback w/ dynomax race muffler/resonator and a summit turbo muffler. Its sorta loud, bout like any aftermarket catback sounds.

I don't think my Enthuza 3" is very loud at all. It definitely sounds a little different from stock, but it's not all that different. The turbo will quiet the car down a lot.

try HKS

hks is nice but way too expensive. im on a budget :)

To answer the title of this thread:

The OEM exhaust.

yeah, but its not really suitable for turbo, is it?

a 2.5" with cat, resonator and muffler will not be loud.

http://youtube.com/watch?v=R_IU4OnItxA

This is with a 2.25" borla catback with an exhaust leak between the DP & Cat.

The additional turbo noise wont have cops looking if you arent boosting around like a dickwad.

My car is quieter than any miata with an aftermarket exhaust.

I have a Maremont metal cat, a 2.5" Dynomax resonator, and the largest 2.5" straight-through Magnaflow muffler that would fit. I think it's 4x8x22":

pics:
http://forum.miata.net/vb/showpost.p...9&postcount=15

wow... i might just give it a try later! i want it to be as quiet as my rsx type s. i dont really like loud exhausts

A stock exhaust might not be any more resrictive than your crushbent 2.5". I'll repeat what others have said. Your current exhaust will sound completely different with a turbo that with your super. Don't change anything until you get that kit on. See if what you have is OK 1st.

+1 to get the turbo on first. Cops won't give a second look to a 2.5" free-flow muffler if you aren't constantly on the boost. The turbo is WAY more conspicuous than the exhaust is.

Don't think the crushbent stock 1.875" is more restrictive than crushbent 2.5"?

by the way, that crush-bent 2.5" REALLY made a lot of difference with my supercharger. it really became considerably quicker w/ stock pulley. dont know how it performed with 62.5mm pulley because i shredded a belt next day after pulley installation and didnt drive car since :/
i did push it pretty hard few times with new pulley and of course it was way faster but i never redlined it past 2nd gear to really see how good it became :)

OK, so I'm an idiot. Never claimed otherwise. My thesaurus has crushbent listed as another word for restriction. I haven't seen a stock exhaust is so long I guess I remembered them wrong. Thought they were mandrel. Dee dee dee.

most stock exhaust pipes are mandrel bent i thought. I dont recall seeing crush marks on the stock exhaust when it was still around.

what you do is open up the stock exhaust slide the straight pipe through it, drill a shit load of holes in the straight pipe and wrap it with housing insluation, then put it back in the stock muffler body. it will work like a cherry bomb and look completely stock, that and with the turbo on you shouldn't have a problem. just make sure you patch it up good so the smog tech doesn't look at it too closely.

i have no problems with smog. afterall im going to put megasquirt and that turbo definitely doesnt look stock. now... if only i could get a sticker from one of those carb'd kits :)

and that would be illegal, so don't even think about it.

right...

False. I measured backpressure on a stocker and I got 8 psi at just 6 psi of turbo boost. I measured the backpressure on mine which has a handful of crush bends, and I got ~3.5 psi at 10 psi of boost, with a Maremont Metal Cat.

so yeah, i installed turbo today and sound is awesome! idles silently. at full throttle my turbo is WAY louder then exhaust :)

told ya' so.