Cal Club Autocross Forums

Jason Flores wrote:

Ken Motonishi wrote: I gotta find what the rules are for passing sound.

just for reference for everyone..


In some states (including california), noise limits for modified exhaust systems are established by a SEMA model bill (attached) and applicable to an easy to administer test standard. The SEMA model provides for the testing of vehicle exhaust noise to a standard adopted by the Society of Automotive Engineers (SAE) with an established noise limit of 95-decibels (SAE J1169). Under the SAE standard, a sound meter is placed 20 inches from the exhaust outlet at a 45-degree angle and the engine is revved to three quarters of maximum rated horsepower. The highest decibel reading is then recorded.

WOW, 20 inches, I was thinking it was 20 FEET!!

FYI, J1169 was canceled in 2007. J1492 replaces it. there are some significant differences, namely that it's not a constant RPM measurement anymore and that they use Fast, A weighting in stead of slow.

my car is stock if u need anything. one of the tail pipes fell off the stock muffler so it looks like a dx with the single tube.
have another stock header seperately if you need. EF Si is the same 4-1 as the EG DX/LX.

Jason Flores wrote:...and the engine is revved to three quarters of maximum rated horsepower.

Whatever *that* means. Ugh.

They can rev my car to 72!!!