Thread: EPA Noise Test
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      08-17-2012, 05:27 PM   #18
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Originally Posted by Totti View Post
Legal limit is 90db for cars post '83 chief.
Totti is spot on with the level, it is 90dB. Eisenmann are the only company that publish sound pressure levels and they are:
Eisenmannn SPORT Version for the BMW M3 (e92):
Decibels (stationary vehicle): 92 dB at 6,225 RPM
Eisenmann RACE Version for the BMW M3 (e92):
Decibels (stationary vehicle): 102 dB at 6,225 RPM
Even the sport which is quite tame is well over the legal limit. The rule of thumb is if it sounds good itís illegal, if it tastes good its fattening or bad for your liver.
The Akrapovic is substantially louder than the Eisenmann sport and will probably test around 95dB, but the problems donít end there. Any system that is a full replacement system has high flow or no cats. The Akra Evo has 100 cpsi (cells per square inch) cats, stock is around 600-700cpsi. This means it will also fail emissions test and why you get CEL if you donít install a delete-R or get a tune.
Bottom line is that virtually any aftermarket system will fail noise levels and if a full system replacing the OEM cats will fail emissions.
So if itís a fine just pay and be glad, if you are going to be called in for a full inspection I would fit the stock system first and get it tested, then revert back to your Akra and hope it doesnít happen again
We all love our exhaust systems and they make a huge difference to the driving pleasure of the car but if you live in a nanny state thatís what happens. We have roadside inspections here and if you get hauled in to one of those it would be a defect notice, although they usually save their harassment for young guys driving skylines or similar.
By the way, sound pressure level apps on phones, they don't work as the microphone on your phone can't measure the high levels. You have to spend a lot of money on a dB meter and set up properly to prove what you already know