noise pass by requirement

[johnab]

Does noise pass by having direct relation with 1st, 2nd...order or type of vehicle like 4/6 cylinder ?

or just a standard requirement like US has around 75 dBA. (While vehicle testing, the exterior noise shouldn't exceed 75 dBA or depends on counry requirement)

 

[GregLocock]

No, it is the overall dBA for that vehicle, it has no legislated frequency content other than that implicit in the A weighting scale and the gears and speeds used by the vehicle.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Rob45]

Yes, although the allowable level for light vehicles (generally, under 10,000 lb GVW) varies from state to state, with some localities having their own unique requirements.
That requirement is 80 dB(A) in the worst cases, and the measurement distance is 50', not the 25' more common in Europe. Per SAE J986.

Heavy duty vehicles face a federal (national) requirement also of 80 dB(A) but per a somewhat different test procedure, SAE J366. Still at a 50 foot distance.

And beware the manufacturers who game the test with engine control software "features" such as GM put on the ZR-1 Corvettes...

Regards,
- R