new to the integra scene. Im a broke *** collage student, and wanted to get a little noise out of my bone stock 98 integra ls. so I unbolted the stock muffler to see what it would sound like. liked the tone, so I completly took it off. I have stock headers, cat, and resonator. Is there anything I need to worry about as far as low back pressure, will this have a negative effect on my engine. let me know

 

your motor will be fine. but damn you can get a decent sounding muffler for like $70 on ebay or sumthin. and it will look a whole lot better!

 

Backpressure is never a good thing.

The reason people used to think it was necessary is because they put too large of an exhaust on a car, and the loss of exhaust velocity reduced performance. You want no backpressure, but the maximum exhaust velocity possible.

I think the car will be too loud under WOT use without at least some form of muffler in there (I've started up my 2000 GSR without the stock muffler, sounded good and deep but was too loud when I revved it). However, if you want to run it like that, it won't cause mechanical issues. Consider adding a turn down to the end of the pipe to help keep the car cleaner, you should be able to find an exhaust shop to make one with the same flange that the muffler section has, or can have them cut off your existing flange from the muffler and add the turn down.

 

thanks for the replies guys. with the stock resonator mine isnt very loud. Im gonna get just a pipe made to get the exhaust to the back of the car just to mount to the stock res., rather then just have it blow out ouderneath. does anyone know about any laws in california against not having a muffler, could they bust me for it? because mufflers arent for emmisions, just to quiet the sound right?

 

Mufflers are used to keep your car under the legal db (decibel) limit.
In CA its something around 86db to be legal around the city i think.

My buddy used to run his 96 prelude with no muffler for a long while, something around 6mo-15mo with no problems from police. He made sure to drive extremely mellow around town.. Like TunerN00b said, under WOT its very very noisy.

 

^ LOL WUT?! i believe its 95 or 96

86 is pretty close to stock for a lot of cars..

 

Technically, yes, a muffler is legally required. However, many cars do not run what would be legally considered a muffler without issue. I have a car with only a resonator and glasspacks, and as far as the law is concerned it is not equipped with a muffler. I've never had a cop give me a hassle over it, but they don't seem to care about loud exhausts on old cars (1975 Spitfire).

US automotive exhaust limit is 95dB. Not sure how they actually test, as there is a world of difference measuring at the tailpipe under a WOT pull than there is 20 feet back under cruise conditions.

 

how about gas milage? has anyone seen lower or higher mpg's? does it make a difference at all?

 

bump

 

Finally someone who knows what they are talking about!
It is quite refreshing...

Op you might see a slight increase in mileage, but most likely decrease because you will have your foot to the floor just so you can listen to the sound it makes...

 

https://honda-tech.com/forums/general-discussion-debate-40/whats-legal-db-sound-exhaust-cali-2370214/

its around 95 dbs


this thread lists the CA CHP legalities for exhaust noise