Noise Testing - Best Practice

[puckrup]

Have managed to borrow a dB meter for the weekend to measure how loud my de-catted Sagaris is. Off to Nurburgring and Zolder in 3 weeks time and have invested in a pair of ACT Quiet Tails.

What is the accepted method to measure noise levels? At the Ring last year it was a static test @ 3500rpm from 1 metre. Should I measure at waist height? Directly pointing to side exhausts? At 45 degrees to rear of car?

Plan to measure before and after and post results here !

Neil

[GreenV8S]

Start at the tail pipe; if you have multiple tail pipes on the same face of the car start from the mid position. Visualise a line sticking straight out from the side/rear of the car at that position. Visualise a line with is 45 degrees up and sideways from that first line. Position the meter at the required distance from the car along this second line. Make sure you use the correct noise scale (usually dBA, but check). Make sure there's nothing behind you that can reflect the sound, and the engine and exhaust are up to temperature. Don't assume that the readings you get at home with your own meter will be identical to the official readings.