amount of decibels of sound off headers.

[Arns85GT]

Hi all,

I am trying to design some sound suppression for my header project. My goal is to get the car below 90 db. What I can't seem to find is the amount of decibels of sound a 60*v6 has off open end headers. If I know my starting point, then the muffler choices will be easier to understand

Anybody know?

Arn

[Superdave]

with open headers mine pegged the dB meter i borrowed from work which IIRC is 120+, probably closer to 130.

these engines are LOUD

[Arns85GT]

Thanks

Thanks,

I wondered if that was the case. So, what muffler did you use and what did it measure, or did you measure the relative sound?

Arn

[bszopi]

At what point are you trying to measure the sound? I have a professional meter at home, so I can take some baseline readings if you want. If you are right next to the open header, then yeah, I could see it easily exceeding 120dB. But if you are 3-4ft away, it will be significantly less.

[Arns85GT]

50 feet

I need the reading to be good at about 25' - 50'. The reason is that I have neighbours with babies and youngsters, plus a couple of shift workers and if it is too loud it just isn't very considerate. I don't want to make enemies after all.

I'm wondering about the db's of sound at about 50' or maybe 25'.

If the db's off the headers are about 100 db at 50', and I have a race muffler rated at 100 db max and a tip muffler that takes it down another 6-8 db's, I should be below 90 dbs, where I want to be.

So what if you are standing 25' behind the car? Any more help on this?

Thanks BTW

Arn

[bszopi]

90dB is pretty loud. I bet, at 50 ft, even a loud exhaust would be less than that. My car isn't all that loud (I have a Flowmaster 50 Series), but I'll go ahead and measure at the exhaust pipe and then 25ft and 50ft away to show just how quickly it diminishes. If its loud at 50ft, it'll probably be because of surrounding sounds, not the car's exhaust.

http://www.gcaudio.com/resources/howtos/loudness.html

[Arns85GT]

Thanks

That link is a real good education. thanks for it. I'll bookmark it.

I'll be looking forward to your posting. it will be a big help.

Arn

Looking at the chart, I have a snow blower and if it is 100 db I definitely need the car quieter.

[Arns85GT]

Here is a plan. Good or bad?

I can use the Schoenfeld sanction approved muffler (100 db) at the collector and not interrupt flow.

I can put in auger baffles down stream or the Moroso spiral muffler.

The Moroso knocks about 6-8 dbs off the sound on its own.

Comments?

Arn

[geldartb]

sometimes depending on torque converter lockup inside my car im hitting 110db.

ill measure it in the springtime but its pretty damn loud when you get on it.
highflow cat then just pipe then the ageing flowmaster 80. 2 1/2 from the manifold back.

unbolting it at the mid flange at the strip it gets pretty loud

[1988GTU]

[OT] I've noted that having a turbo on a 660 really takes the DB's down [/OT]