Car sounds great. Like really great.

I measured using my android device and two new apps. Got different numbers. It's still super uncomfortable in cabin.


Outside at idle, <10' away: 58-62db
Inside at idle: ~65db
Inside at 3500rpm free-revving: 75-78db

i could try to get some db readings later but my app sensitivity is questionable. I sat in my stock accord during my lunch break and it was reading 75db at idle..

I used both "Sound Analyzer App" and "Sound Meter" this last go around. Both spit out identical numbers.

kk i was using Decibel X. I just downloaded soundmeter. I'll post my results once i get home

My Datalogging Group Buy is still open, as it happens. Unfortunately, what you're describing is all-too-common among the "ricer" crowd, and is undoubtedly just another unfortunate side effect of your excessive rear brake bias. This may not make sense to you, but if you'd competed in F Prod for as many years as I have, you'd understand.

Are all the exhaust gaskets good? U personally checked they are not leaking air?

I had rb header, stock midpipe, rb dual tip exhaust and it was almost stock quiet. Just a tad more aggressive sounding.

on my current car while while waiting for EFR turbo I put on stock nb2 header, into 3" catless exhaust with a big magnaflow muffler, it was louder, but still perfectly ok on the hwy.

now I drove my new EFR turbo setup to a shop with Just an open downpipe to the muffler shop to get it welded to my exhaust, and I seriously almost went deaf. Even with full ear, ear muffs it was rediculously loud.

Every exhaust gasket is brand new. I installed them. No leaks. I even installed brand new gaskets again when i swapped the diff despite the old ones only having been on the car for 200 miles. No leaks.

On the same phone? If so, then that's because they're both using the same uncalibrated microphone hardware.

Sound meters on phones are toys. Proper sound meters not only need to be calibrated, they also need to be frequency weighted because the same sound pressure is perceived as different volume at different frequencies. The phone sound meter apps I've seen are all flat.

--Ian

You already know the frequency of droning, as you know the RPM. Is there space beneath the car to add a tuned Helmholz resonator suppressing these frequencies?

Also, have you done the bare minimum interior soundproofing, like stuffing foam or other similar shit in the body tunnels and whatnot? Get a couple sleeping bags and unroll them and stuff them in the trunk so they fill the space; see if that changes the sound at all.

Right. This is why i've used the term "unscientific" a few times in this thread when pertaining to measuring decibels with a phone.

I can pay more dollars to swap out my muffler that i paid dollars and hassle to get for one that has a Helmholz resonator. It's something i'm considering, just trying/wanting to gather more data points. I'm mostly trying to determine if what i'm experiencing is "normal" for this setup or similar, though i'm sure that request got lost in the initial many posts of irrelevant bantering.

No i haven't. I can mess with that, but no amount of soundproofing is going to make what is currently happening acceptable. Looking for data points/experiences with similar/anecdotes, not solutions at the moment.

My father(in his 60s) has a VVT swapped NA6. Full poly suspension/diff bushings with mazdacomp engine mounts, RB header and unresonated power pulse muffler w/poly hangers. Magnaflow hi-flow cat.

I find it slightly quiet unless youre flooring it. My father doesnt mind it and the wind noise bothers her more than the exhaust(top down for that). Ill try to get some DB readings.

(also last year I can the same set up on my car but MSM swap(w/o turbo) and AWR engine mounts + FM 2.5" turbo exhaust. That was louder but not really drone-y or unbearable)

My car is like concealer's. NA6 with VVT and 6758. Full 3" exhaust with resonator, cat and end can. The drone is driving me nuts. I have pool noodles underneath the parcel shelf and around the fuel pump/tank cover void. Full carpet. Even with the opt full of luggage it will drone like hell. From the outside my exhaust sounds sporty but not overly obtrusive. The intake noise and spool is certainly louder.

I'll try the big ass MT Magnaflow muffler next.

install the big ass magnaflow muffler and enjoy life.

I have full 3" catless, no resonator, only the muffler and its VERY quiet. Almost stock quiet. Just deeper sounding

Helmholz. He's your huckleberry.

I believe you can tee off the existing exhaust system and solve this problem. Takes some reading to nail down, I imagine.

big magnaflow (MT flavor) for eunos
helmLOLZ for revealer

lose the 1hp and toss a cat back on it. problem solved.