Exhaust is too loud -- What should I do?

I'm in a pickle. I was overzealous in my exhaust decisions for my Comanche stroker project.

I have a Borla Header and Downpipe, Random Technologies Hi Flow Cat, 2.5" SS exhaust tubing with a Magnaflow Dual output exhaust with a tip behind the mudflaps on either side... (this one)

http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=629

Anyways, it's too loud for a DD as it sits now and it sets off car alarms on my street.

The exhaust shop suggested putting in a resonator in front of the muffler. The guy said it would 'tame the exhaust' and that it would 'take it down two notches'

I guess I don't know if that's actually enough. I must be getting old. I want to listen to NPR while driving to work.

Does anyone have any experience with resonators? How much of an impact do they make?

Thanks!

Matthew

Dunno - I opened up my exhaust a few years ago, and I revel in setting off car alarms (pretentious (*#@)$*@()#$ - what a waste of electronics...)

I guess it's just me, but everyone else out here has car alarms, has them cranked up way too high, and they're always on things I wouldn't steal if I were so inclined. Really - what makes you think I want an Acura that needs scratch plates? By the way - your "system" sucks - I can't tell what you're listening to!

I guess I'm not quite that old yet...

A resonator will proabably help, or you could try different tips - I think they're called "Supertrapps" - but you're supposed to be able to change baffles to change sound levels.

Me, I plan on putting in a cut-out when the next opportunity presents itself. Gotta figure out where to run the control cable, tho...

5-90

5-90 said:

I guess it's just me, but everyone else out here has car alarms, has them cranked up way too high, and they're always on things I wouldn't steal if I were so inclined. Really - what makes you think I want an Acura that needs scratch plates?

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I agree. I'm not a fan of car alarms. Statistically, they are like the boy who cried wolf anyways. They get false triggered so often that people just ignore them.

5-90 said:

By the way - your "system" sucks - I can't tell what you're listening to

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I spent all my money on making my truck run

5-90 said:

I guess I'm not quite that old yet...

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I'm shocked and scared at myself about this self discovery. I'm only 31 years old!

5-90 said:

A resonator will proabably help, or you could try different tips - I think they're called "Supertrapps" - but you're supposed to be able to change baffles to change sound levels.

Me, I plan on putting in a cut-out when the next opportunity presents itself. Gotta figure out where to run the control cable, tho...

5-90

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I'll go with the resonator and then let the system build up it's carbon deposits and stuff. That apparently helps mellow out the sounds some. It's wierd. I took it out for a spin tonight and it just didn't seem as loud to me. But it definately has a sound 'spike' right at 2k RPM. Up to 1500 it's good, and after 2k it actually seems to quiet a bit. I hesitate to call it drone but it must be something very similar.

It's cool having people whip around looking for the muscle car at the ice cream stand though

Let me know what it's like with a cutout!

Matthew

Wanna sell the Borla?

Sorry - I wasn't ranting on you. The problem with "Back to School" at my age is that you get surrounded by all these 18-19-year-old nitwits, and everytime there's a "club day" or somesuch in the main quad, I always have to walk through a wall of that awful racket. Makes me wanna back in and put in a GWAR CD and fight back!

The death knell for car alarms for me was when I heard one start off, and the four cops taking a coffee break didn't even bother to look. Damn things are useless. I'd sooner spend the money on booze.

And the "your system sucks" was for those kids who put all their money into subs, with nothing to fill out the top end. Hell, if you're running OEMR crap, you're still sounding better than those damn fools - I can tell what YOU'RE listening to! I've only got a single sub, and it's just for fill-in and bass riffs...

5-90

5-90 said:

Sorry - I wasn't ranting on you. The problem with "Back to School" at my age is that you get surrounded by all these 18-19-year-old nitwits, and everytime there's a "club day" or somesuch in the main quad, I always have to walk through a wall of that awful racket. Makes me wanna back in and put in a GWAR CD and fight back!

The death knell for car alarms for me was when I heard one start off, and the four cops taking a coffee break didn't even bother to look. Damn things are useless. I'd sooner spend the money on booze.

And the "your system sucks" was for those kids who put all their money into subs, with nothing to fill out the top end. Hell, if you're running OEMR crap, you're still sounding better than those damn fools - I can tell what YOU'RE listening to! I've only got a single sub, and it's just for fill-in and bass riffs...

5-90

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No problem 5-90. I didn't feel like you were ranting at me in the least. I do a lot of work as a consultant at a high school in the area and I feel like a different breed from the kids that walk the halls.

I'm running an inexpensive JVC deck ($150) and pioneer speakers mounted in the original locations and have been happy with it overall. In my Comanche I don't have any room for a sub at all. If anything my audio space is over 'bright'.

Gil -- You can have the borla for 6k Heh, I would call that a steal...a stainless steal

Seriously though --

I did a bunch more reading and I think I'm basically going to overhaul the exhaust completely. I'm going to go with the resonator, 2.5" in to 2.25" outlet single pipe magnaflow and one exhaust pipe. As a DD/work vehicle I need to drive up to client sites without rattling windows.

Let say that stock exhaust is a 1, open pipe with no cat is a 10. (Loudness) I would think that my current system is a high 6 or 7 (while accelerating). Adding the resonator would bring it to 4 or a 5. I think switching mufflers to the single outlet would bring it to 3 and keep the peace with my neighbors, and more importantly, my fiance. (It sets off her car alarm too)

I'll see if the exhaust guy will cut me some slack on the cost of the components. He's a good guy. I don't see why he wouldn't. He knows this isn't his fault. He told me it was going to be loud. I just didn't understand what loud was.

I'll let you all know how it pans out.

Matthew

Forgive the ignorance, but is a resonator the same as a glass pack? I remember reading GoJeep's article on his exhaust setup, and he shoved in a glasspack to make things a little quieter. They aren't expensive either, IIRC. I also know somebody who did that with a modded YJ and got it down to sounding (tolerably) like his TVR.

Not exactly, a resonator operates on the Helmholtz principle while a glasspack is just a fiber encrusted normal muffler (IIRC).

r@m

I have the same setup on my 89 stroker except I have the Dynomax Turbo mufler (single outlet, $20) and it does not set off alarms - it does have a spike at 1500 - 1600 but has a Comp Cams 235 cam which might account for the different RPM range. I know the hi-flow cat does increase the allowed noise, but in my case its fine at cruise (2000+).
I'd try the resonator and see what happens.

A true resonator is an expansion chamber (no packing) designed to slow down exhaust velocity. I'm going to check with my exhaust guy this afternoon about what options I have. I don't see the point of another glasspack in front of the main one. He was surprised by the amount of sound as well. More than likely it's the hi flow cat making the difference. It actually has mellowed out some since yesterday. Been driving it around some today and working it at different RPM levels. I also think I've acquired a bit more throttle control since yesterday. Maybe having loud exhaust will help me save gas money cause I won't be stepping into it so much

rsalemi - I have the comp cams 239 in mine. I'm very pleased with my cam, and the idle has already smoothed out quite a bit since I picked it up. I went with new LCA based engine mounts and a new stock tranny mount although I have a MORE poly tranny mount sitting here if the stock doesn't hold up.

The engine has been running great. I've probably put 200 miles on since I picked it up Tuesday. I'm bringing it in next Friday to have the mechanics go over it, check the plugs, look for leaks, tighten bolts, install my stainless brake lines etc...

Which once the exhaust is squared will be my next area of work -- the brakes. This things gets up and goes in a hurry but it takes a while to slow down.

Matthew

I also have the MORE engine mts and stock trans mount. I installed a Daystar trans mount(automatic) but its about 1" higher than stock and causes serious vibes on deceleration. Talked to their tech support who said it will break in?? I replaced it with stock and no more problems. I have Rustys Poly engine mts in the MJ and they do transmit every vibration!!!

5-90 said:

I always have to walk through a wall of that awful racket. Makes me wanna back in and put in a GWAR CD and fight back!
And the "your system sucks" was for those kids who put all their money into subs, with nothing to fill out the top end. Hell, if you're running OEMR crap, you're still sounding better than those damn fools - I can tell what YOU'RE listening to! I've only got a single sub, and it's just for fill-in and bass riffs...
5-90

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ha ha. kinda hijacking, but i couldn't resist. i've got 2 kicker 15's on a fosgate and lets just say my high end will match it. it's fun driving through the parking lot at my college. when the white posers start "bumping" that rap crap, i pop in the garth brooks and turn it up. it's funny to see their faces when they realize that they got blew away by a redneck.

xuv-this said:

ha ha. kinda hijacking, but i couldn't resist. i've got 2 kicker 15's on a fosgate and lets just say my high end will match it. it's fun driving through the parking lot at my college. when the white posers start "bumping" that rap crap, i pop in the garth brooks and turn it up. it's funny to see their faces when they realize that they got blew away by a redneck.

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I love the idea of backing in with GWAR blasting, and Garth Brooks to the cRap crowd takes a close second, but my favorite of all time was a CD that came with a cereal box when my son was 4. Mickey Mouse and Friends singing feel-good oldies is my favorite when it out-louds some punk at a red light. It's all about embarassment.

"THUMP, THUMP...hey, goofy, let's sing a song!"

just a follow up for those who care -- I brought the truck in to get the resonator installed and it was too long. He's going to have to order a shorter one. The truck has gotten quieter and the drone has moved up in the RPM range...now it's a little over 2100 where it starts.

For the time being I'm just going to go with the resonator and see how it works out.

Matthew

just an idea- what would/might 2 stock mufflers of a slightly smaller size do for sound loss and power gain?

i had a chevy blazer w/ 3+" exhaust system and yes the drone and volume does fade with time, i would say that at 1K it all settled to a very respectable level.

but after it settled i went with the Rockford Fosgate 750 on the base 2 12's and 1 15" sub and a Nokamichi 1K for the mid's and hi's on an alpine head set and Bach and Bethoven for the cRap at the lights and on base LOL...

Installed a magnaflow resonator in front of the muffler. Vehicle doesn't set off car alarms coming down my street anymore, and the droning is pretty much gone. It still sounds great when stepping on the gas.

I'm happy with the sound level now.

Matthew

Congrats on getting the tone settled down, Matthew. I know what you went through, because I did the same thing last year on my 89. I had every muffler type known to man on it. Moroso SpiralFlow, Glasspack, MAC FlowPath, Flowmaster single chamber; all were too loud. Like yours, mine had a resonance around 1500-1800 rpm that nothing would help with. (Maybe this is common with in-line sixes......?)

I finally settled for a Thrush turbo. It was more restrictive than the others, but did soften the mid-rpm resonance somewhat.

I still have the MAC Flowpath, with plans to install it on my 'new' 96. Maybe with a resonator like you did......

Runnin'OnEmpty said:

Congrats on getting the tone settled down, Matthew. I know what you went through, because I did the same thing last year on my 89. I had every muffler type known to man on it. Moroso SpiralFlow, Glasspack, MAC FlowPath, Flowmaster single chamber; all were too loud. Like yours, mine had a resonance around 1500-1800 rpm that nothing would help with. (Maybe this is common with in-line sixes......?)

I finally settled for a Thrush turbo. It was more restrictive than the others, but did soften the mid-rpm resonance somewhat.

I still have the MAC Flowpath, with plans to install it on my 'new' 96. Maybe with a resonator like you did......

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Thanks -- I do think the nature of the 'boat engine' sounding exhaust is to some extent unavoidable with these particular mills.

Seems to me some stock muffler from a big old caddy or something would fit these engines well and keep sound down without significant exhaust restriction. I've never seen any conclusive proof though.

Ahh the irony. I brought the truck to an inspection station in MA today. They guy said I would fail IMMEDIATELY due to the fact that the exhaust is too loud. Legally in MA only stock exhaust is acceptable (or exhaust as quiet as stock) I was dumbfounded. Harley's are WAY louder than my truck is while accelerating. To top it off it was too warm for the Dyno to properly calibrate so I couldn't even get my emissions checked. He said to come by again tomorrow. He won't pass or fail me, just run the emissions test as a diagnostic.

I can't believe this crap!

Matthew