sirguy01

im looking to make a quieter exhaust for my car. i am currently running a turbo set up witha 3inch all the way. However due to some stupid kids in my neighborhood the cops have enacted a new plan to pull over all modified cars to ensure they are street legal, emissions compliant and tolerable sound. I have reason to believe that my car will be borderline in noise. However im looking to make maybe a 2.5 or a 3 inch exhaust but using maybe a high quality muffler to make it quieter. Im already running a cat and resonator and silencer.. but still seems really loud to me. Im just wondering if anyone has or had a good set up that didn't attract cops or attention for that matter.


thanks

sirguy01

common anyone?

Jamez

Start with the largest, longest quality pre-silencer you can fit under your car. Don't search for resonators, search for actual mufflers. For example, on my own exhaust that I want to quiet down I'll be replacing a burnt out glasspack resonator with a 6" wide, 18" long Magnaflow muffler. I would never use it as a main muffler but as a resonator I think it stands a chance of doing a decent job.

Follow it up with with a good size main muffler. Stay away from the N1 style ; for a straight through muffler to do its job it needs lenght and thickness. Also stay away from cheap components as they burn out way too easily and soon enough don't absorb much noise at all.

You know what they say about dual exhausts on a 4 cylinder car being useless? Well, not quite. A dual exhaust allows the use of less restrictive mufflers without as much of a noise penalty. If you do go this route you'll need to make sure both mufflers get the same amount of gas flowing into them otherwise one will do most of the job while the other just stands there.

You could also try a "turbo" muffler if you don't mind the restriction but the problem with non-straight through mufflers is that there often is no guarantee that any substantial noise reduction will be achieved over a straight through unit. This is because these mufflers have generally been built for the domestic market. It's really hard to make a V8 sound bad so the manufacturers didn't have to put a lot of effort in finding a decent sound ; if it doesn't make your ears bleed then it's all good. If you ever hear a Flowmaster on a 4 cylinder you'll see that it doesn't make much less noise than a straight through exhaust (but doesn't flow nearly as well).

Sorry for the long post but that's pretty much all I have learned on the topic of noise reduction on my quest not to sound like a damned bumble bee.

sirguy01

thanks for the post ill keep it in mind. what kind of muffler are you using? and where are you gonna find such a big muffler to fit under your car?

2point2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sirguy01 &raquo;</TD></TR><TR><TD CLASS="quote">thanks for the post ill keep it in mind. what kind of muffler are you using? and where are you gonna find such a big muffler to fit under your car?</TD></TR></TABLE>

I'm using a vibrant and it's quite quiet.

I know what you're going though. the cops are going to be ****** this year.

Jamez

Like I said, going in to replace the resonator is a round Magnaflow 6" across and 18" long. Lenght wise it isn't any longuer than your stardard resonator. It's a bit thicker (typical resonators are like 4" across) though and has better internal construction so it shouldn't burn out. My main muffler is an Integra Type-R unit which would be quiet were it not for my burned out glasspack of a resonator and Carsound cat.

The thing about size is to find the largest one you CAN fit. Mufflers come in all shapes and sizes, you just need to take some measurements and buy the appropriate one. Straight-through mufflers work by absorbing noise, unlike stock mufflers who cancel out the sound freqencies. The longuer the exhaust gas is in the muffer and the more stuff there is to absorb noise, the quieter your exhaust will be.

formby

i got tired of my loud ***/droany exhaust and decided it was time to upgrade to a more silent less restrictive exhaust. I bought a MagnaFlow Polished Stainless Steel Muffler 2.5" #14416[$70] and thanks to taco i bought a Turbo II muffler 2.5" from auto zone[$2o] and the rest is .[2.5"].








a video of the sound...i'm the crx in the far lane throbbing the trottle

http://videos.streetfire.net/v...7.htm

m2c....BTW i wouldnt do the dual exhaust crap

92CHB

Links not working for me

FlashTypeR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92CHB &raquo;</TD></TR><TR><TD CLASS="quote">Links not working for me</TD></TR></TABLE>

formby

http://videos.streetfire.net/v...7.htm

Minor Threat

Recent setup I just did was full 2.5 inch mandrel bent exhaust to a Dynomax Ultraflow.

Cat was cut off, hollowed out and then slipped over the 2.5 pipe and welded on. Looks like a cat if you're just glancing under the car.

This system is dead quiet, it is a tiny bit louder/deeper than stock, but it is only loud if you really get on it, cruising around it's quiet and streetable, and doesn't drone at all.

TeamNextGenChris

pretty much any straight thru muffler is not going to be quiet enough-at least not quiet enough that the cops around here won't hassle you.i'd think it'll be the same way in your area since they're spcifically looking for it.
i've done a few 2.5" setups with a Magnaflow round muffler in place of the cat.that gives the cop the illusion of a cat being there should he look,and helps muffle the sound some too.then i use the longest Magnaflow round muffler i can fit as the resonator.then i use the longest oval Magnaflow muffler i can find.that's the quietest straight thru exhaust i've ever heard.
keep in mind the smaller the piping,the less noise,all other things being equal.the setup i listed above will be considerably louder in 3" over 2.25".

the problem with a multi-pass muffler is they kill performance with a turbo.on my stock B20 daily driver i have the Magnaflow "cat" and resonator with a knockoff Mugen twin-loop muffler.it's extremely quiet,and perfect for my low HP,low revving B20.
the best thing i've found for a turbo car is an exhaust cutout.on my turbo'd coupe,i have 2.25" piping to a cheap multi-pass muffler.it's as mellow as stock,and flows just as bad too
i have an electric cutout about 6" after the turbo.that gives me all the performance when i want it,and dead silence when i'm cruising around.cops don't look twice at me.

if you do decide to go with a full exhaust over a cutout,i think the only way you'll get it as quiet as you need to at 3" is with a multi-pass muffler.most "turbo" mufflers are really restrictive,as the gas must make three immediate 180 degree turns within the size of the case.the Mugen style mufflers seem to flow better IMO since the bends are larger in radius,and actual tubing,not just made up of flow directors like in a turbo muffler.only problem is none of the knockoff Mugen mufflers are available in 3".they're also made of crappy materials(i had to repack mine after a few weeks.now it's been working fine for a year).my suggestion would be to maybe use a dual in/dual out Magnaflow muffler,and make a twin loop style muffler.that,along with quality mufflers for the test pipe and resonator should get you where you need to be sound-wise,with the smallest power loss.
Chris

sirguy01

i've been reading about the thermal exhausts, are they quieter? There was also another guy on the forums who was selling a custom made itr exhaust. i was thinking i would just buy it and butcher it. i'm going to go with a big resonator/muffler and a long as possible muffler for my car. I heard cherry bomb mufflers are good for muffling sound, some guy used one as a resonator and he said his car was stupidly quiet. However they are really cheap which obviously poses the question how often would it be before i have to replace it.

thanks for the input so far guys... my quest for quiet 3inch exhaust still continues.

Jamez

Cherrybomb = glasspack = bad. They basically burn out under a week, after which you might as well not have anything there at all. Also, some have louvered cores instead of perforated, real bad for flow.

AspectIndustries

I need to replace my glass pack resonator with a magnaflow 6" round muffler. Hmm, I wont how would this improve over the glasspack. Hopefully its worth the extra mola.

TeamNextGenChris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by synik &raquo;</TD></TR><TR><TD CLASS="quote">I need to replace my glass pack resonator with a magnaflow 6" round muffler. Hmm, I wont how would this improve over the glasspack. Hopefully its worth the extra mola.</TD></TR></TABLE>
you'll probably want to stick to the 4" round Magnaflows for a resonator.the 6" cans are too big to tuck under the car well.you'd tear it off in no time.
they're well worth it over a cheap glasspack.
just this past weekend i replaced a glasspack resonator on a Civic with a same length Magnaflow.it made a big difference in the volume and tone of the car.the owner said that the car was quiet when he first had the glasspack put on,and the car just got progressively louder as it wore out.
Chris

Jamez

I posted in another thread the other day about that. The 6" does fit, although I had to remove the heatshields and flaten out some gussets to keep it from touching anywhere. It's still a very tight fit and ground clearance is compromised a bit but I'm not worried since I'm not lowered anymore. If I had to do it again I would go with a 4"X22" instead of a 6"X18" model but I was uncertain the 22" model would fit (which it does, there is a total of 28.5 inches of piping to play around with). Live and learn I guess.

BTW, this coming saturday I'll cut my old glasspack in half and take a picture to see and show everyone what happens inside after a while. Although just from knocking on it you can tell it's just an empty can now.