I keep coming across these DB killers in Italy and have NO clue what they are.
Are they supposed to muffle the noise? make more noise?
dB = decibel (unit of sound measurement)
DB killers = sound mufflers
Usually are inserts in the opening of the exhaust that reduce airflow dampening the sound and slightly reducing power. I don't think any of the xx9 systems have DB killers but I could be wrong. BTW, most people leave them out/remove them anyway.
EU homologation laws about noise emissions are really nasty nowadays. DB killers are just caps intended for racing exhaust systems. Basically, you use them on the street and maintain street-legal homologation . You'll take them off for your racetrack days .
However, some tracks do lately require to use them (e.g. Laguna Seca)
P.S. Yes, some Italian companies like SPARK do sell dB killers for their 999/749 exhausts
I dislike db killers quite a bit as they often negate a large portion of the gains to be had by a full exhaust. Why spend $1500-$3000 on an exhaust for only a drop in weight and a visual difference! We stopped carrying ZARD exhausts with db killers and only offer them without at this point.
The Remus exhaust cans for the 9 series come with DB in them as well. A total PITA to get them out but what a sound once they are. They say you can put them back in but once you pull them out and hear the difference you wont want to. I pretty much destroyed one of them getting it out so it wont be going back in anyway.