How loud is loud?

[yorkie_chris]

http://www.hottrax-online.com/produc...ducts_id=15149

98dB means nothing to me, does that mean standard cans, or will my full system with no packing in the can be alright?

Well I'm gonna have a viper can with da baffle out I can't wait how loud will that be

[yorkie_chris]

Yup it'll sound sweet, but whats that in dB?

Reason being I'm wanting to do a trackday, but don't want to ride 110 miles only to be told I'm too antisocial to ride, sod off home.

[tigersaw]

Its difficult to gauge 'loud' without correct measuring equipment. For instance my road legal Arrow can has people putting their fingers in their ears its so 'loud', but it meets legal specs.
It also depends on how they measure the 98dB - is it at 600RPM on a drive by in second gear, or simply burbling on tickover?

The small print says:

Please note that for the avoidance of any doubt all
motorcycles will be tested to conform to the ACU
blue book engine speed guidelines.

Though that throws up nothing in my quick google search

Yeah I was thinking the same thing, unless they have a db metre which is caliabrted how will they know!

I would put da baffle in, which i beleive with my can makes it road legal....its depends on how much of the person doing it is a jobs worth i guess

Haha I was with some guys when I wa college, one Sunday we did a db test on his ICE, lol the college got a phone call from an aresy neighbour they heard a disco in their living room ace! We were disppaointed it only got to just 110 db.

By the way 110 db is a jet liner taking off, aything above can damage hearing on a permant basis. What people fail to realise about sound, is that it must be a pure sounds, ie no spikes and not dirty, it should sounds clean if it makes sesnse. Its hard to explain but you an tell when it something doesn't sound right, I made ppl reshoot becaseue I had a feeling that it didn't sound right, I guess you neeed to know what to being hearing out for.

Its the quality of the sounds, over how loud its....by increasig the volume of the sounds, it changes the wave form, but can distort which is bad. Quality sound is better than loud crap sound.

As for the track leave da baffle in, I would if in dought stick da old end can if it bothers you, otherwise get a db a metre but really even temperature can effect it.

[yorkie_chris]

Problem is, my old can won't fit, and will make it run slobbery rich.

[Stu]

It should be measured at about 5000 rpm with the microphone (or whatever) about a meter behind & above the exhaust.
98 is pretty quiet for a trackday I think. A standard system is obviously less than that but if you've changed it to something nice it could be borderline. Try & get it tested, baffled or look for a trackday with higher limits. You should be able to find 105 dB (which is many times louder).

As a reference my can measured 114 dB. And if someone is going to measure you it's not a matter of how much of a jobs worth they are - you will either pass or fail & go home.

By the way Bluethunder you sound like a real gangster rapper are you?

[northwind]

Even if they use a meter you've also got to know what the measurement method is- a dim memory suggests the ACU method is 1 metre away at 45 degrees at 3000rpm but that could be total, total rubbish, I really don't know where I got that from

98rpm isn't loud... According to the measurements I took, all with my oh-so-precise mobile phone at 1 metre, the stock exhaust idles at 89db and makes 103db at 7000rpm. By comparison, my race system makes 97db at idle and 111 at 7000rpm.

I would have thought that most unbaffled aftermarket cans, might be too noisy for that limit.

bloody hell only showed you the site 10mins ago and look you've made a thread, & already has 10 odd posts lol. good site this