# Tomei Ti decibels!



## wildboy (May 2, 2010)

Ok guys and gals, pinched the sound meter from work this afternoon and popped out to a local deserted airfield to check the decibels on my car.
(Just need to check tomorrow that I had it set correctly cos the readings are quite high lol)

Standard engine/head/turbos
Unknown stainless downpipes
Stainless decat
Tomei Expreme Ti catback

Test carried out 50cm @ 45 degrees
Idle - 104.5 dB
3000rpm - 121 dB
5000rpm - 123 dB

May need a trackday exhaust!


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## WillRobDon (Jul 29, 2006)

That is loud! Maybe try a silencing decat first? To bring it down around 100?


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## wildboy (May 2, 2010)

I already have a Japspeed one in the garage!
Cat is on at the moment for MOT so will retest with that on, then fit the decat silencer and try that.
Lastly I will be cutting up my decat pipe and adding a 76mm diameter stainless flexi joint in it.
I will post up results as I get them.


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## Mikster (Feb 17, 2006)

Whoa thats loud...is that right


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## wildboy (May 2, 2010)

Mikster said:


> Whoa thats loud...is that right


I know lol, need to double check tomorrow at work and make sure I didn't have it setup wrong:nervous:
It is a calibrated sound meter though......


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## matty32 (Dec 18, 2005)

Glad you got round to measuring it mark


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## [email protected] (May 19, 2006)

Maybe the dB weighting was wrong? Should check it was set to read A weighting which is similar to the human ear & is what noise testing is generally measured against.
If it was set to say C weighting it would read a lot louder as the lower frequencies are not cut off as much as with A weighting.

Also thought it was generally measured at 1m distance? Just measuring it at 1m would probably drop it by at least 3dB


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## carbonfootprint (Apr 21, 2010)

Sounds too loud, that's jet territory I think


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## tarmac terror (Jul 16, 2003)

MSA blue book says 0.5m at 45°. 
Reg 5.18.1 (although my source may well be an old one!!)

TT


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## wildboy (May 2, 2010)

Yep had a check and it was C-weighted doh!
Once my mot is done later this week I will redo all the tests and post the results.

Did seem a bit high.


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## mambastu (Feb 13, 2002)

Interesting to see how noisy the Tomei TI is as a 3.5" system. My old 3.1" Blitz NUR Spec R tested at 115db at 4000 rpm at Goodwood a few years so I had to replace the rear box with a quiet mild steel Jetex 3" rear box for trackdays. New exhaust will be a custom 4" system but hoping to use large boxes to get it quiet enough for track use.

Cheers

Stu


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## Steve (Sep 21, 2001)

Yup that's loud, you mite get yer collar felt chap


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## mhhforyou (Jul 12, 2012)

Do you also measured with the silencer from the Ti? 

I have also the Tomei Ti but with T78-33 Kit, Greddy Intake, and Apexi Catalyser its definitely under 100DB at idle without silencer.


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## wildboy (May 2, 2010)

Ok guys, fitted the Japspeed silenced decat and gave it a go today

So,
Kakimoto stainless downpipes
Japspeed silenced decat
Tomei Ti catback

Idle - 90dB(A)
3k rpm - 107dB(A)
5k rpm - 115dB(A)

I'll get my flexi decat on later this week and get some more readings


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## GT4 Addicted (Feb 16, 2005)

my R34 GTR with a Blitz Nür Spec cat back is way louder than my customer R34 GTR fitted with a Tomei Ti catback :nervous:


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## matty32 (Dec 18, 2005)

It's not always about being loud 

The blitz is a loud system (too loud for me - I had one in my previous 34)


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## mhhforyou (Jul 12, 2012)

wildboy said:


> Ok guys, fitted the Japspeed silenced decat and gave it a go today
> 
> So,
> Kakimoto stainless downpipes
> ...



all without silencer??


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## wildboy (May 2, 2010)

mhhforyou said:


> all without silencer??


Do you mean the insert in the tail pipe?


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## mhhforyou (Jul 12, 2012)

wildboy said:


> Do you mean the insert in the tail pipe?


Yes


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## wildboy (May 2, 2010)

Then yes, no silencer bung fitted for this test. To be honest I can't ever see it being fitted either lol


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## V1H (Aug 30, 2001)

How does this compare to the kakimoto n1 both in loudness and sound(without bung)? 

cheers


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## wildboy (May 2, 2010)

My kakimoto was a much deeper noise and the tone didn't change much through the revs, the tomei gets a nice rasp when the revs get higher


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## V1H (Aug 30, 2001)

thanks, i have the std n1 and find that too loud without the bung even at idle, agree that it doesn't change that much in tone through the range unlike a blitz nurspec but interested in a titanium exhaust that isn't as loud.


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## cooljustin (Jun 6, 2009)

Would you like to swap with my Trust Ti exhaust? it's just way too loud with a straight pipe to the end. :chairshot



wildboy said:


> Ok guys and gals, pinched the sound meter from work this afternoon and popped out to a local deserted airfield to check the decibels on my car.
> (Just need to check tomorrow that I had it set correctly cos the readings are quite high lol)
> 
> Standard engine/head/turbos
> ...


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## wildboy (May 2, 2010)

Ok guys and gals, retested today with the dB meter set on 'A' weighting.

Kakimoto stainless steel downpipes
"Flexi" decat pipe
Tomei Expreme Ti catback

Idle. - 94 dB(A)
3000rpm. - 113 dB(A)
5000rpm. - 119 dB(A)

Quite loud!

Edit. This was carried out at exhaust height. 200mm or 8"


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