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Old 03-23-2009, 11:19 PM   #1
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Default Sound levels w/ turbo+no cat+enthuza?

Couldn't find a thread that pertained to this exactly. Kinda seeing if anyone has some readings

Basically one of the locations for my local autox has a sound level restriction. The limit is set at 94 dB and they have the reader set correctly with forgiving conditions for the most part. They'll run the meter at locations that don't have restrictions so people can try out different mufflers,silencers, etc. I was the loudest at the last event, lol. It read 97.9 dB at WOT probly around 6300 rpm.

Im running stock header to a 2.5" text pipe to Enthuza's 2.5" turbo exhaust. Was wondering if anyone with a test pipe + enthuza catback with a turbo has any idea on how loud they're car is.

I'll be running a gt2560r with FM's manifold and 2.5" downpipe.
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Old 03-25-2009, 05:12 PM   #2
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I have the 3" enthuza with a bullet cat and people can hear it grumble from a mile away. I don't have any db numbers, but it can't be track legal at 93db.
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Old 03-25-2009, 08:24 PM   #3
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For a short while, I ran a test pipe with my 2.5" Enthuza and a Greddy turbo. It was slightly louder than with the cat in place (a 2.5" ceramic-core unit) but by no means completely outrageous. On the downside, it was a tad stinky.
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Old 03-25-2009, 08:29 PM   #4
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I bought this and it really quieted down my car: eBay Motors: 93-97 MAZDA MX3 323 626 Catalytic CONVERTER REPLACEMENT (item 170307813235 end time Apr-01-09 15:54:23 PDT)

I haven't tried it with a full exhaust but it appears that it would work. The local autocross is fairly strict and I haven't had a problem running the resonated testpipe and a turndown. For $6.90 it might be worth a shot. It's 2.5 inch and bolted right up to my Begi 2.5" downpipe.
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Old 03-25-2009, 09:25 PM   #5
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Greddy turbo, test pipe, 3" Enthuza:



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Old 03-31-2009, 04:58 PM   #6
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The cat isn't a huge sound attenuator anyways, when I first put my 2.5" together I rolled without a muffler for a day. It was LOUD.
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Old 03-31-2009, 05:17 PM   #7
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I have a 2.5 Enthuza and test pipe that I just installed yesterday. I can say that it isn't much louder than my Racing Beat Power Pulse set up I had. Very liveable.

I would have gone 3", but I DD this car. Unlike some, I will sacrifice some power for comfort.
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Old 04-23-2009, 04:47 AM   #8
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3" Enthuza with 3" CAT from them:

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Old 04-24-2009, 03:25 PM   #9
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The 3" Enthuza, left exit, test pipe, and no muffler is louder.
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Old 04-24-2009, 04:00 PM   #10
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It's loud enough I drive with the HT on and windows up like a *****. I'm excited to add a cat next February.




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Old 04-24-2009, 04:36 PM   #11
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is the testpipe resonated? if not, have Jason make you one. (FYI, just 3 glasspacks and no muffler is definately too loud)
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Old 04-24-2009, 04:42 PM   #12
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Quote:
Originally Posted by Oscar View Post
is the testpipe resonated? if not, have Jason make you one. (FYI, just 3 glasspacks and no muffler is definately too loud)
All that my OTM has after the cat is 3 glasspacks (well, resonators), and that's all stock.
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Old 04-26-2009, 02:11 PM   #13
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whoring this out:
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Originally Posted by johnwag View Post
Hustler's car in front of the shop.



and that is with a cat.
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Old 04-26-2009, 02:19 PM   #14
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Sounds pretty good Hustler.. definitely has taken out the rasp and a little of the volume of my setup. Does it drone at all?
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Old 04-26-2009, 02:21 PM   #15
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Quote:
Originally Posted by kotomile View Post
Sounds pretty good Hustler.. definitely has taken out the rasp and a little of the volume of my setup. Does it drone at all?
my cell phone sucks, but I have to put it on speaker and next to my ear in the car. After a few hours of road tripping headaches start. Its not bad for 30-minute commuting. It actually hurts the ears in tunnels and passing cars on the loud pedal, but the turbo is part of that.

edit: Its not my daily driver so I don't mind the noise. I would pull the cat but don't want it any louder.
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Old 04-26-2009, 02:22 PM   #16
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Sr20 t25
FM mani and 2.5" downpipe
Custom 3" testpipe
3" alumanized steel enthuza
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Old 04-26-2009, 02:33 PM   #17
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Quote:
Originally Posted by hustler View Post
my cell phone sucks, but I have to put it on speaker and next to my ear in the car. After a few hours of road tripping headaches start. Its not bad for 30-minute commuting. It actually hurts the ears in tunnels and passing cars on the loud pedal, but the turbo is part of that.
At least you can hear your cellphone in your car.. I barely can at anything over 40. I don't take roadtrips in it, which is one of the reasons it's coming out here on a truck as I type this. I'm not looking forward to driving to TX in it after I graduate here. My exhaust is just like yours, but with no cat, and I also don't have any boxing around the intake yet, however much sound deadening that might add.
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Old 04-26-2009, 02:49 PM   #18
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I have tried both with and without a cat on my last Miata that had a Greddy setup, RM 2.5 downpipe, and the Enthuza 2.5. Definitely prefer running a cat. A high flow cat will not inhibit power enough to justify not having piece of mind from cops and keeping your hearing.
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Old 04-26-2009, 03:01 PM   #19
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Would a decent sized resonator take enough off or would a cat be pretty much the only option to bring it down to a comfortable sound level?
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Old 04-26-2009, 03:06 PM   #20
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Why not just run a proper high flow cat?
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