I just got an m4 gp pipe for the gsxr1000. I figured it'd be louder but I thought m4 wouldn't make it this loud. The police have a sound decibel measuring device that I'm pretty positive I can get someone to come over and use. I was wondering how WERA measures the decibel level, ie How far back from the pipe and at idle or what rpm, speed. Thanks
RTFRB v) All race machines must use muffling devices that limit the sound to 105dBA. The noise level will be measured while the machine is on the track during practice sessions and racing events. If a machine measures over the limit it may be subject to a “Meatball Flag”. A static test may be used off track to measure the noise level by holding the dB meter at 48 inches and at a 45 degree angle from the exhaust opening(s). The engine will be steady at 1/2 of redline during this test. If a machine measures over the limit with either test it will not be allowed to participate in any further events during the weekend until it has been brought under compliance. Riders may also be fined or otherwise penalized for non compliance. Certain race tracks may require lower limits and at these tracks those sound limits will be enforced and noted on race entry information.
There is a thread somewhere that warms people about certain exhausts on the new Gixxer's that may be too loud for racing
http://forums.13x.com/showthread.php?t=105391 From the big man himself... The M4 pipes I saw on some of the pro bikes at Mid-O I am sure would not have passed the WERA (or AMA for that matter) rules on db limits. They do sound good though...
Slightly O T, How does H D promotions get away with their straight pipe bonus class that they run in their florida ccs races?
That's why I ordered the M4 race high mount and stayed away from the GP. But having said all that the M4 I have is pretty loud on my 1000.
what year gsxr1k? i have an M4 on my bike and it is loud, but not that bad. Sounds very cool actually. The shorty pipes from M4 for the 06 600's were friggin way loud however.
My buddy ran one on his gixxer 6 this year and there was only one bike louder than his all year. That was an 06 R6 with an Tsukigi
Every fiberglass-packed can gets louder with time. If you repack it, it goes back to how it was new. Personally, I tend to like them as they get louder...but I'm deaf. HG can do the loud pipe bonuses because the events are at a track (or tracks) where he can get away with the noise.
I have an m4 shorty on my '06 gsxr 600. If I remember correctly, when m4 came out with the pipe, they had a recall (or maybe just a correction to later ones) to make it quieter. I can't remember if 105db was before or after the change, but it is still pretty damn loud.
I am still deaf in my left ear from being behind the guy who started this thread (t-2) at Barbers. Those shorties sound sooooo good tho'. Glad i don't have to race around them
