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Failed sound level check at Autox

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Old Apr 22, 2007 | 08:20 PM
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Default Failed sound level check at Autox

Well I need to do something to quiet my exhaust down slightly. I was at 97.something on the decibal meter at the 75 foot away mark. In my local club I need to be under 95. I think its even lower for the NER club and I know they would toss me.

I've only had 3 different setups. 1 was stock, 2 was the corsa exhaust, 3 is what I have now:
Kooks LT's with high flow catted ypipe
corsa catback
avg cam 224/228 .560/.570... something on those lines

So I'm not sure exactly what would be the best balance between not losing too much power yet keeping the sound down. Maybe I only need to toss on an exhaust tip that points downward?

I figured a lot of you guys have heard and compared different setups, especially Slowhawk and crew

ps... I'm f*in pumped because the sox just hit 4 solo hr's in a row from the point where I began typing this until when I posted this thread, lol, completely sick
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Old Apr 22, 2007 | 08:56 PM
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that was sweet go SOX"S
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Old Apr 22, 2007 | 09:05 PM
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Hey Bryan why not stick a bullet style muffler in the I-pipe. I ran Mac-mids, ory, moroso Sprial flow, and GMMG at Lime Rock and didnt get tossed. If you are looking for it to be toned down a little a a regular bullet muffler should do the trick if you are looking for a bigger noise reduction the sprial flow would be the ticket.

John
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Old Apr 23, 2007 | 09:34 AM
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Yeah I think the mids help you out there. I have longtubes. I may consider mids, even if it puts me down about 20 horse. Maybe a cutout for the speedway events, with a quiet exhaust closed during autox.

I'm wondering if doing all this will mess up my A/F ratio and will need to be retuned
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Old Apr 23, 2007 | 09:49 AM
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Thats weird, I have a corsa, LT's with dynatech catted Y pipe, my car is a lil louder then stock, its nothing crazy. I think your highflow is looser then most.
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Old Apr 23, 2007 | 09:56 AM
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I have a cam too though. If you had a cam, you would be a bit louder depending on how big it is.
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Old Apr 23, 2007 | 09:57 AM
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Go with an SLP Dual Dual cat-back. Flows prety good and probably the quietest cat-back you can put on.
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Old Apr 23, 2007 | 10:52 AM
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I agree with Dave. You can try a Magnaflow that is cheaper.Should be quieter than what you got.If all else just throw a bullit on there too.

Forget the midlengths.You have nice headers already.

What some people don't understand is when you add a H/C setup with raised compression the exhaust will get louder and change tone.I hated my Corsa after doing a H/C setup.
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Old Apr 23, 2007 | 11:05 AM
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Welp, I know nothing about the car aside from the post, never saw head work of any sort and saw a small cam. I know tone changes. I know the diff of a corsa with cats and without. My 383 was tooooo loud with no cats and a small hotcam. As for Db level, I would think its how well the cats were working to deaden the sound.

Stock cam, stock heads, with a new catted Y I can honestly say its louder but close to stock.

Eitherway, I hope it gets fixed soon so you can run.
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Old Apr 23, 2007 | 01:08 PM
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Originally Posted by Slowhawk
I agree with Dave. You can try a Magnaflow that is cheaper.Should be quieter than what you got.If all else just throw a bullit on there too.

Forget the midlengths.You have nice headers already.

What some people don't understand is when you add a H/C setup with raised compression the exhaust will get louder and change tone.I hated my Corsa after doing a H/C setup.
That sounds like a good solution. If the slp dual dual is quieter, I'll get that over the Magnaflow. Where does the bullit go, between the cats and muffler?

The Corsa performs a pretty obnoxious exhaust belch when you lift the gas after WOT with my cam. Lots of people think its cool, but it gets annoying after a while.
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Old Apr 23, 2007 | 01:34 PM
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http://store.summitracing.com/partde...5&autoview=sku

Sound reducer cones for headers/mufflers. There is little or no power loss from these.
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Old Apr 23, 2007 | 05:14 PM
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I used the cones they didn't cut me back too bad and did work.
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Old Apr 23, 2007 | 06:32 PM
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dual/dual quiet and doesnt hurt power to much untill you start pushing ALOT of compression and power but still quiet
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Old Apr 24, 2007 | 06:18 AM
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Just a shot in the dark but something i considered doing to the vette cause its to loud and may help you anyways. Borla has the plate system with reduced size holes in it. They are just a thin sheet of metal that you could put in where your catback comes together somewhere and it would be like a gasket and a smaller size hole. Giving you mroe torque but making the car much quieter and cheap easy in and out??? Just a shot in the dark.
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Old Apr 24, 2007 | 07:27 AM
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Can you still buy the dual dual these days?
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Old Apr 24, 2007 | 07:51 AM
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Originally Posted by z28bryan
Can you still buy the dual dual these days?
only used ones
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Old Apr 24, 2007 | 08:06 PM
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SLP doesn't sell them anymore?
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Old Apr 24, 2007 | 08:29 PM
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Originally Posted by davered00ss
SLP doesn't sell them anymore?
nope, they stopped sometime last summer. when i was looking for one, SLP said speed inc. was pretty much the only shot i had at getting one that might be sitting on a warehouse shelf somewhere, but they were sold out when i called. i just ended up getting a used one from a friend.
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Old Apr 24, 2007 | 09:56 PM
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wtf they have a limit as to how loud you can be on autox? i guess im never going to one my car wakes the dead.
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Old Apr 25, 2007 | 09:32 AM
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Originally Posted by F-Bobby
wtf they have a limit as to how loud you can be on autox? i guess im never going to one my car wakes the dead.
Some of the residents around Devin's complain I guess. Go figure, what were they thinking when they moved next to a military base and airfield?

In any case, my exhaust is annoying the hell out of me so fixing this is also something I want to do for my ears.

So say I went the Magnaflow/bullet approach how does that get setup? I looked up bullet mufflers and saw that there's two loudmouth types. Would this setup be like combining a Magnaflow and Loudmouth exhaust together? Doesn't the Loudmouth resonators go between the rear axle and the y-pipe?
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