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Tips for lowering dB? (Tomei expreme Ti)

Does anyone have tips on how to quiet this exhaust down? NCM has a 103dB limit at 50 feet and I doubt installing the silencer do much to help meet

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Old 11-13-2017, 12:10 PM   #1 (permalink)
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Default Tips for lowering dB? (Tomei expreme Ti)

Does anyone have tips on how to quiet this exhaust down? NCM has a 103dB limit at 50 feet and I doubt installing the silencer do much to help meet this level especially since the installation of test pipes.

Are there any products (baffles, turn downs) that can be easily adapted to the exhaust? Or will a custom solution be needed so I can run at NCM?

Thanks in advance for any advice.
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Old 11-13-2017, 12:34 PM   #2 (permalink)
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probably going to need to do something custom. This is the reason I got rid of my Tomei. they did however just come out with a v2 silencer you can find on Z1's site that *may* work. But the tomei is just so loud I doubt it
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Old 11-13-2017, 02:44 PM   #3 (permalink)
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Originally Posted by echoshotz View Post
probably going to need to do something custom. This is the reason I got rid of my Tomei. they did however just come out with a v2 silencer you can find on Z1's site that *may* work. But the tomei is just so loud I doubt it
Thanks for the heads up, I wasn't aware of the v2 silencer. Maybe if I have a turn down added to it as well as some baffles on the inside I can reach my dB goal... I refuse to give up my Tomei lol.
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Old 11-13-2017, 02:49 PM   #4 (permalink)
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There is a product called a spiral silencer which I use on my race car. I don't have a US reference but you might want to check Spintech Mufflers who are US based. Google should help out
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Old 11-13-2017, 11:19 PM   #5 (permalink)
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If you know what side of car the meter will be on. You can add turn downs that point away from that side. I've seen guys do that.
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Old 11-14-2017, 06:58 PM   #6 (permalink)
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found a promo video for the tomei silencer

https://www.youtube.com/watch?v=emHA...ature=youtu.be

the last one sounds about as loud as a cat fart. may be your best option.
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Old 11-14-2017, 07:21 PM   #7 (permalink)
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Originally Posted by Brendan View Post
found a promo video for the tomei silencer

https://www.youtube.com/watch?v=emHA...ature=youtu.be

the last one sounds about as loud as a cat fart. may be your best option.
This comes to mind.
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Old 11-14-2017, 08:06 PM   #8 (permalink)
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While I can't give you a link to one, I've seen inserts that go in the end of the muffler that are designed to reduce the sound.

Also the turndown idea works pretty well. Even just pointing the turn down at the ground can make a big difference. Not sure the diameter of the tomei muffler tip but I've commonly seen autoxers use a HVAC duct elbow as a turn down with just a hose clamp holding it on.
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Old 11-15-2017, 08:19 AM   #9 (permalink)
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Quote:
Originally Posted by BGTV8 View Post
There is a product called a spiral silencer which I use on my race car. I don't have a US reference but you might want to check Spintech Mufflers who are US based. Google should help out
Is that for a full muffler? I was hoping for something to add to my silencer and be able to take on and off.
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Old 11-15-2017, 08:21 AM   #10 (permalink)
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Quote:
Originally Posted by Rusty View Post
If you know what side of car the meter will be on. You can add turn downs that point away from that side. I've seen guys do that.
Left side coming out of turn 2b onto a straight... I've thought about a turndown to the ground but maybe pointing it away from them will work better?
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Old 11-15-2017, 08:23 AM   #11 (permalink)
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Quote:
Originally Posted by gomer_110 View Post
While I can't give you a link to one, I've seen inserts that go in the end of the muffler that are designed to reduce the sound.

Also the turndown idea works pretty well. Even just pointing the turn down at the ground can make a big difference. Not sure the diameter of the tomei muffler tip but I've commonly seen autoxers use a HVAC duct elbow as a turn down with just a hose clamp holding it on.
Will the HVAC duct hold its shape at track speeds?
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Old 11-15-2017, 08:53 AM   #12 (permalink)
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Quote:
Originally Posted by Laomatik View Post
Will the HVAC duct hold its shape at track speeds?
It's only an elbow piece I'm talking about so I would think so. I know they do just fine at speeds approaching 90 mph. No knowledge beyond that but I wouldn't see any reason they would deform.
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Old 11-15-2017, 10:02 AM   #13 (permalink)
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It's only an elbow piece I'm talking about so I would think so. I know they do just fine at speeds approaching 90 mph. No knowledge beyond that but I wouldn't see any reason they would deform.
Something like this?

https://www.amazon.com/Duct-Elbow-De.../dp/B00BLUA5Z8

I think that could actually work. I just hope it's enough. Does anyone know of any cheap decibel meters I can use to test?
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Old 11-15-2017, 10:05 AM   #14 (permalink)
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Originally Posted by Laomatik View Post
Does anyone know of any cheap decibel meters I can use to test?
Free iphone app? Or search Amazon.
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Old 11-15-2017, 10:22 AM   #15 (permalink)
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Quote:
Originally Posted by Laomatik View Post
Something like this?

https://www.amazon.com/Duct-Elbow-De.../dp/B00BLUA5Z8

I think that could actually work. I just hope it's enough. Does anyone know of any cheap decibel meters I can use to test?
Bingo.

Here's a link to a picture of a 350z using one
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