Exhaust dB register

[Homer]

Interesting stuff. Sound testing is quite a difficult one. You've got a few variations to consider like quality of the sound tester, what revs you do the test at, if its windy, how far away and which angle from the exhaust, etc. We normally test them between 4500-5000rpm approx, and they should get quieter the higher the revs. Try testing one of them again at 5000rpm instead of 4000rpm and see what happens.

Steve L's 3" twin box system on his single turbo 3" dp/mp was tested at Oulton Park with a calibrated sound tester, 4500rpm and registered 100db in the garage which normally makes them louder. And the same exhaust on jaymdee car is 2db louder with I presume 2.5" decat pipes and stock turbo which will make it quieter.

 

Hope that helps a bit.

 

Agree completely Paul I wasn't taking the measurements with a ruler and protractor or anything like that It was just by eye from the exhaust exit, but they were hopefully consistent. There was no wind on the day, but I do think the surrounding buildings played a bit of a factor, which is why we tried to move the cars away from them a bit to do the readings.

 

The meter is not a calibrated professional one, just a £90 one from Maplins. That said it has been pretty much spot on when compared to the readings taken at the track days - quite a few of us have used it to test beforehand.

 

This thread is only meant as a guideline, and of course results will vary due to conditions they were thaken in. Will do a few more at Japfest if it's not too windy/noisy to see how they compare.

 

Concerning the RPM the measure should be taken at, is it still 3/4 max rpm at the track days?

[SteveR]

Great Thread Darryl;

 

shame not to see a single "single" supra quieter than 100db at 4K

I know mine wil be as quieter than than and as quiet as singles can be, but remember these reading are at just 50cm(!).

 

Concerning the RPM the measure should be taken at, is it still 3/4 max rpm at the track days?

yes

[Paul Whiffin]

Agree completely Paul I wasn't taking the measurements with a ruler and protractor or anything like that It was just by eye from the exhaust exit, but they were hopefully consistent. There was no wind on the day, but I do think the surrounding buildings played a bit of a factor, which is why we tried to move the cars away from them a bit to do the readings.

 

The meter is not a calibrated professional one, just a £90 one from Maplins. That said it has been pretty much spot on when compared to the readings taken at the track days - quite a few of us have used it to test beforehand.

 

This thread is only meant as a guideline, and of course results will vary due to conditions they were thaken in. Will do a few more at Japfest if it's not too windy/noisy to see how they compare.

 

Concerning the RPM the measure should be taken at, is it still 3/4 max rpm at the track days?

 

Yes mate 3/4 max rpm.

[Dash Rendar]

Great Thread Darryl;

 

shame not to see a single "single" supra quieter than 100db at 4K

 

Reckon mine might come in under par. I need to get my TRD checked out... Still, not sure there's much point. Those exhausts seem to be as rare as a redneck with all his teeth.

[Wez]

Great Thread Darryl;

 

shame not to see a single "single" supra quieter than 100db at 4K

 

Mine is, it's approx 98db as measured by the testers at Brands Hatch

[JamieP]

Can you bring the db meter to suprapod mate, like to see what my boostlogic is.

[DodgyRog]

You can add mine on there as well if you do it at SupraPod

 

N/A full decat, standard mid section and Nur spec S

[lui]

Mine as well please Darryl mate always wanted to know :eyebrows:

[Homer]

Can you bring the db meter to suprapod mate, like to see what my boostlogic is.

 

Yep, I'll bring it along but 'Pod is not the best place to get a reading as there's a lot of background noise.

[Luxluc]

Interesting thread Darryl.

 

I will try to find a DB meter .. and test my HKS Super Dragger.

[martini]

Would like mine done

[Homer]

No problem guys, just find me on the day (shouldn't be too difficult!)

[Gaz6002]

Mine is, it's approx 98db as measured by the testers at Brands Hatch

 

So's mine

[Paul]

Out of interest how far away from the exhaust are you testing? Got access to a meter from work and thought I'd give it a go:)

 

Edit !!! Should have read the thread properly. ' All readings taken at 50cm from the exhaust at 45 degrees right of the exit angle '

 

Sorry.

[SteveC]

I've taken readings today as per post number one.

 

Tanabe Medallion Touring, double 3" decats, UK TT.

 

Idle: 67dB

 

4000rpm: 84db

[neilp9876]

I can add my readings to this as well...

 

Hks silent hi-power, TT

 

First cat, second decat, 81db idle, 101db 4500 rpm.

Double decat, 83db idle, 104db 4500 rpm

[mrgee2jz]

If anybody has a db gauge and wants to test mine. Im in ilford, I'm pretty sure is the loudest I've come across soo far, in fact soo loud I'll be changing it all over for a completely different system very soon. Gt4094 with Custom 4" all the way to 2 back boxes

 

My other sup is a tt bpu decatted and Hks hi power, nice and quiet

[GlennK]

Ok - checked my exhaust:

 

Apexi Bomber III (JASMA approved) 3". Fully decatted. BW9179 Single. Idle = 94dBA. 4500rpm = 102dBA

[TwinturbJay]

is there a way i can restrict noise below 80 db without losing too much power?

[Guest PaulT]

My stock NA auto has been reading 78/79 all season.

 

Paul.

[Littler]

Bump for a member who's looking for this thread

[Supra Kong]

[Kaan W]

So was the blitz nur spec R tested with or without the bung in the end?

[Steve Paine]

For all of you out there with iPhones there is an app that you can get that measures noise. It is called NoiseWatch. I haven't dared to use it outside yet as it registers at 85 to 90db in the car whilst driving!

[letmeshowyou]

good call Steve. I'm gonna measure mine I think.