I'm going to Laguna for a track day, bringing my 1100 air cooled Ducati. Has an 848 exhaust, so I bought some stock cans, as noise limit is 93 DB. 93 db is not much, and I'm a little concerned about getting dinged for being too loud. I'm looking to grab a few things to throw into the toolbox in case I need to come up with something quick at the track to quiet the bike down. Obviously we don't want to get kicked out for being too loud after traveling 2000 miles to ride. I've seen some people put wire mesh over the exhaust outlet? Any other suggestions? I downloaded an iPhone decibel meter app, after I put the stock cans on tomorrow, I'll try and get some kind of reading.
A little trick we learned at Bridgehampton: If your carbs/throttle body are relatively exposed, line the bottom of your fuel tank with foam. This muffled intake noise 2-3 dB on a 750SS.
more often than not, u can just go past the noise booth at 20% throttle in 5th or 6th gear. its just one straight between T5 and T6. then u rip everywhere else. stock cans help a lot. but people still get away with aftermarket cans and this "technique". some bigger bikes fail sound on intake noise alone if you go by the booth at full throttle. so don't rip by there no matter what. I tried making metal inserts out of tin cans for a KTM RC390 exhaust. they def quieted it down and robbed power. but the metal started to fail from the heating and cooling halfway through the day. so I pulled them out so I wouldn't spread metal shards all over the track. that little bike was loud-ish, but I still didnt fail sound.
The sound meter is on the RIGHT, going up the hill, after turn five, and before the bridge. Try to attach some sound deflecting material (heavy plastic (.125”) or sheet metal) at the end of the exhaust so that it covers the right side, and behind the exhaust outlet. You want it to deflect it Up and/or Left. The idea is to have indirect sound arriving at the sound meter, vice direct. If the sound meter cannot ‘see’ the exhaust outlets, until you are well away from the meter, it will read many db lower. We fabricated something like they use at the mile flat tracks (“boom boxes”) that let the exhaust exit to riders left. If you have an open airbox with Velocity stacks, it can also trip the db level.
I wouldn’t do a damn thing!! https://ultimatemotorcycling.com/20...cement-regulations-win-win-for-motorcyclists/
4/1 ehh? I remember seeing a picture of a bike that had the spigot at the end of the exhaust can pointing 90 degrees inboard, basically 180 degrees opposite where the sound check was positioned trackside. Want to see some funny shit, check this stuff out: https://www.google.com/search?q=lag...uYTbAhWBuVkKHTazDqYQ_AUIDCgD&biw=1440&bih=713
Yup, pack some materials in the trailer to build something to divert the sound if needed. Definitely roll off the throttle, tried and true cheating always works I don't believe you get a 2nd chance there either, one warning, next time you're on the bench the rest of the game.
Found this. https://www.southbayriders.com/forums/threads/59281/ I know it is another forum, sorry. But there is some good info on how sound is tested at laguna.
Yea it doesn't always work, last time I was there I got popped on an R6 with a stock exhaust while ruining my lap through T5/T6. Stopped at start finish after getting flagged and one of the Seca sound people started giving me crap about the noise. I started out being nice saying I had stopped for the flag and he kept harping on the noise. He wasn't supposed to be in the hot pit and wasn't the one I was supposed to talk with about the issue since the trackday provider I was teaching for was running the track day. I hadn't gotten much sleep the night before and was more than a bit cranky. I finally told him that track wasn't worth the hassle from him or the noise restrictions ruining laptimes. He started in again and I started up my bike and he asked where I was going, I said home, that he could fuck off and I didn't plan on coming back. Rode the bike into the truck, tied it down, and headed home. I wasn't the first person he had hassled, the guy in charge of the grid kicked him off the track a few minutes later and told him not to come back while they were running the track day.
I mean, if people are breaking the rules that could possibly get the track fined or shut down and I worked there and supported the track, I'd probably give you crap too. Even if someone acts like an 8 year old when I try to enforce a rule that they knew about and accepted before attending.
