Well about a month back, I got my car inspected for the first time with my custom exhaust system. It was failed for being too loud. I took it again to another place for a second opinion, this time the Lexus dealership, and they wouldn't even bother starting the inspection because they said its too loud. Right now I'm running a true dual 2.25" from the primary cats. The center cat is gone, along with the two resonators. I also have a pair of Rod Millen Magnaflows for mufflers. While I pass on emissions, it seems to me I'll never be able to pass safety because of the way the new law in Massachusetts is written:


Section 540 CMR 4.04 - Procedures for Inspection of Non-Commercial Motor Vehicles
(5) Muffler and Exhaust System. Accelerate motor to test for prevention of unnecessary noise and emission of any unreasonable amount of smoke. The exhaust system, exhaust manifold(s), exhaust pipe(s), muffler(s), and tailpipe(s), if designed to be so equipped, shall be tight and free of leaks. System components shall be securely fastened with fasteners in place and undamaged. All motor vehicle exhaust systems shall discharge the exhaust beyond operator, passenger, and/or trunk compartment. Unnecessary noise is herein defined as any noise which is louder than that emitted by the vehicle when equipped with the original manufacturer's equipment. A gas or diesel vehicle will be rejected if, at normal operating temperature, at any constant speed over 15 MPH, (approximately 1,000 to 1,200 RPM's) visible black or blue exhaust emissions are evident.


The bold portion of the excert above is the part in which both mechanics failed me on. I'm planning on getting the resonators put back on in order to pass; however, now I face another dilema. About 2 months back I purchased a pair of IMF headers. I talked to a guy at a custom exhaust shop and he warned me that even if I get the resonators put back on, if I install the headers the exhaust will be even louder than it is right now without the resonators. What should I do? How much louder do headers make our V8s? Should I just scrap this entire exhaust idea given that massachusetts is turning fascist?

 

throw on a stock set of headers/exhaust system go get it tested/safety and swap the headers and aftermarket stuff back on.

 

I haven't installed the headers yet, and swapping the entire system each year will be too much of a hassle and costly (especially since I don't have my old one left). I'm more wondering if I should just sell my headers given that the resonators are giving me enough problems as it stands.

 

headers should not give you too much of an increase in sound...,maybe around 10-20%, My suggestion is to find an OEM system from the catalytic converters and see if that would do the trick. Headers are a PITA to install and remove, but the rest should bolt up quite easily

 

When my friend got new headers it actually got a little bit quieter. So I don't know how much the headers will specifically affect your car. But the thing that is making you car so loud is the mufflers. You need to get some quiet mufflers and you'll pass for sure.

 

Headers mainly change the tone(especially in the upper RPM Range) in my experience.

To cut back on sound, you could get another 2 straight through mufflers inline. Dynomax Ultra-Flow is a very cheap muffler, and virtually identical to Magnaflows internally. You will hardly loose any power and it will cut back on sound immensely.

Also, if you get the inspection done right after the mufflers are installed they wont be broken in and will be very quiet.

 

If you dont mine it quiet then just add in the resonators. If you dont want it like that, make it so that you have a section of straight pipe removable. And then get a piece that has 1-2 resonators per bank made and you can bolt that part in for safety inspection. Unbolt that when you are done. Takes up less room and less of a pain than header swapping.

 

i dont mind it quiet for the time being. I'll miss the sound, but if i must to pass inspection then i must. im planning on eventually moving up to electric actuated exhaust cutouts, but thats when i got the money for them. i think thats my best perminent solution. itll be quiet for inspections and cops, and loud for every other time.

 

I looked up my hometown's bylaws regarding exactly how many decibel's they permit since thats where my car is registered to (and since the state's official law is pretty vague). Accoridng to Ashland, MA the limit for vehicles under 10,000 lbs is 75 decibels. Does anyone know relatively speaking how loud that is? Is that barely above what our stock exhaust sound level is?

 

From multiple sources wikipedia & random I forgot:

"Typical conversational speech at one foot is about 60 decibels, the average pain level is 130 dB and jet engine noise levels can approach 160 dB"

"The perceived psychoacoustical loudness should double with every 10 dB increase"

 

Best advice would be to move out of the communist ****hole that is MA.

 

Yeah, I'd love to move out of liberal gay-pride MA, but I like Boston too much. if only they could move this city to New Hampshire. LIVE FREE OR DIE!


BTW: update - I got the resonators put in today along with an x-pipe finally. The resonators he put on are glass-packs. They flow just a freely so no loss of power at all. in fact, i think its gained more responsiveness in the mid-range (probably due to the x-pipe). funny thing is now my car kinda sounds like my friend's G35 coupe with that light chewbacca growl to it. it still lets people know its a V8 when i floor it, but its definately about half the sound it used to be. if i dont pass inspection this time im going to sue the inspection shop and the state cuz by now my exhaust is as quiet as most stock exhaust systems out there today.

 

Hey Brendon, how are you?

Have you installed the headers yet?

The headers alone wont be much louder then stock, just a little deeper sounding. Also you still got the main cat in place. I know a few customers in Cali that passed the smog test, i guess it all depends on how hard they look for those cats.

 

i would have reccomended just getting a silencer! you put it inside your exhaust tip and it just cuts the hole down to the size of like say a half dollar coin. sounds like stock. my friend has a 40 dollar ebay muffler thats 6in its a pure fart can, but with the silencer it sounds stock.

 

Maybe you could fab a silencer for the pipes? Couldn't be that hard could it? :shrug: