Mister Quickie

before I bypass the muffler on the 951 I want to know if laws requiring a mufflers vary state to state and if so is it the state that the car is registered in or the state that you are currently driving in?

tempest411

They probably do vary, but in the end the message is the same: nobody wants to hear obnoxiously loud cars. And I'm right there with the majority on that one. A loud car is a pathetic way to try and earn street cred.

Paulyy

+1

I had a 3" with 1 muffler. it was to loud and sounded ****. i now have 2 mufflers and it's much quieter and sounds quite nice and respectable. Yes i had a mid muffler and a rear.

SloMo228

Put me in the "don't make your car obnoxious" camp, too. When I was a teenager, I had a Thunderbird with cut-off exhaust that was tremendously loud. I thought I was cool as hell back then but looking back all I had was a car that annoyed everyone and sounded broken.

That's not to say I want a car that sounds like a Camry, either, but it is possible to have a car with a good-sounding performance exhaust note that doesn't cause your neighbors to call the cops on you. Besides, 944s sound ****ty with open exhausts, anyway. Like a 90s highschooler's Fast-n-Furious Honda, except more so.

Mister Quickie

While the options/preferences are good to know, my question was more geared towards legality
And since we're sharing, while i don't need to have an obnoxiously loud exhaust, the stock 951 exhaust is pathetically silent

Van

I'm sure each town/municipality/state has laws that are stated as a max decibel level... However, I'd have to think that a police officer would have to use "subjective judgement" to decide if your car is "too loud".

Look up your town code and see. Or call your local police department and ask.

What I do know is that some of the race tracks in more residential areas (like Lime Rock or Laguna Seca) have noise restrictions, and they are something like 89 db at 50 feet away. A turbo with a straight pipe will be border-line and not pass when the air is dense and/or there are no leaves on the trees... A NA car will also be border-line with a pretty decent flow-through muffler.

V2Rocket

Have you ever been to a 944Spec race? Or just been near one driving?
They run straight pipes and are LOUD...I did some work for a local Spec guy years back and he took the car for a drive around the block...I could still hear him over a mile away...lol

Depending on your noise regulations you *might* get away with a 951 with just a cat installed. The turbo takes the noise level down a lot and the cat helps a lot too.

cringely

In terms of legality, I suspect that the local equivalent of the Dept. of Motor Vehicle regulations will state a certain found pressure level (SPL) in decibels (dB) at a given distance.

If you have a smart phone (e.g., iPhone), there are apps that turn it into a dB meter.

Paulyy

would not use a smart phone as a db meter. not event as a reference point. everything i measured just to even see didn't even come close to my actual db meter.

In Australia we have strict noise laws. post '83 cars need to be 90db or under. measurement is from 45° and 1m away from the exhaust. car needs to be revving at around 4-5k rpm (each car has it's own rpm spot)

a lot of cars are louder and police don't say much, but there is to loud. 100db is loud enough and is where mine is.

V2Rocket

I have one of those decibel-meter apps on my phone, not sure how accurate it is, but it peaks at 90dB...and is always pegged inside my car.

I have a fully stock exhaust system, manifolds to muffler, with the exception of a legal replacement catalytic converter...

Arominus

On an iphone you might have a chance of being calibrated, as there are not too many models. On android, without a calibrated Mic and an app that can use that calibration file, that number means nothing.

Paulyy

even if it is calibrated. you need a filter on it so you don't pick up wind noise.

mytrplseven

There should be a db restriction on my ex-wife.....

Mister Quickie

I called the State Police Non-Emergency line and was told that the code is subject to interpretation by the officer and that's all I needed to hear.

For me, the fact that I even have to appear in court ... I've already lost, so the Camry sound forges on

Paulyy

There will be rules for noise testing. Ask a shop who does EPA tests.