Exhaust Sound Levels
#47
How is the finish better?
Last edited by NorthVan; 02-25-2008 at 10:29 AM.
#49
Not if you use an accurate sound pressure level meter.
Then you know the exact levels for every change or modification.
In 1975 I was the first to work with the CHP to establish noise standards or SPL ratings for accessory exhaust systems.
It's done with the same parameters all the time. No subjectivity. You get accurate answers!
Then you know the exact levels for every change or modification.
In 1975 I was the first to work with the CHP to establish noise standards or SPL ratings for accessory exhaust systems.
It's done with the same parameters all the time. No subjectivity. You get accurate answers!
#51
That's a great tip, thanks! How much do sound pressure level meters run? Also, any general tips on what are some of the quietest free flowing exhaust systems on the market for the 996 X50 Turbo? I am hearing good things about the RUF and wanted to get a few opinions. Thanks!
You can buy a suitable one at Radio Shack for under $50.00.
It's not as precise as mine but it will do a fairly decent job. You can then use it to balance your 7.1 audio system as well!
As to the other two questions I'll have to leave that to the wizards here.
However I would definitely suggest you actually hear the muffler you decide upon.
#52
The one I have is made by Bruel & Kjear and it was $3,500.00!
You can buy a suitable one at Radio Shack for under $50.00.
It's not as precise as mine but it will do a fairly decent job. You can then use it to balance your 7.1 audio system as well!
As to the other two questions I'll have to leave that to the wizards here.
However I would definitely suggest you actually hear the muffler you decide upon.
You can buy a suitable one at Radio Shack for under $50.00.
It's not as precise as mine but it will do a fairly decent job. You can then use it to balance your 7.1 audio system as well!
As to the other two questions I'll have to leave that to the wizards here.
However I would definitely suggest you actually hear the muffler you decide upon.
#53
I spoke to Mike at AWE, and he felt that changing the mufflers (to stock) would result in a quieter sounding system, however I would loose some power. I am going to borrow a dB meter and will run a test to see what level I am at (using SCCA testing methods), I may change the mufflers back the stock PSE system, and take another reading.
ttpower, you may want to try this same change before you spend a lot of time pulling off the Fabspeed system, I would consider all options.
ttpower, you may want to try this same change before you spend a lot of time pulling off the Fabspeed system, I would consider all options.
#54
Make sure the engine is up to operating temperatures so the muffler is hot. take a reading at idle, 1,500 RPM, and 2,500 RPM.
#55
Get a camera stand, etc, and attach the meter to the stand about 18" behind and at a 45 degree angle to either the left or right tip. It should be close to the height of the tips above the ground.
Make sure the engine is up to operating temperatures so the muffler is hot. take a reading at idle, 1,500 RPM, and 2,500 RPM.
Make sure the engine is up to operating temperatures so the muffler is hot. take a reading at idle, 1,500 RPM, and 2,500 RPM.
#56
You can take readings there as well but you'll see probably 5-10 dB differences from the method I suggested.
You may also get influences from other sources at 50'.
#57
When I get the meter I will take readings both ways. I am curious how loud it is at the source.
#58
So what I stated is for reference as to how the CHP makes its tests.
#59
You sound like you have experience with the CHP, what kind of fine do they have for noise violations?
#60
I do know of a person stopped in Los Gatos CA for what the officer "believed" was a "noisey" muffler on a Challenge Stradale. The claim is absurd, and very easily defensible.
I do not know the full outcome of this situation, because the driver was also cited for 105+, AND he had another speeding violation 2 weeks before!
So while he could easily defeat the "noise" claim he had bigger fish to fry with two speeding tickets= 4 points in CA= no license!!!