sound testing at nationals

[mayno323]

Is everybody that races going to get tested at every round? If so what is the db limit and what exhausts will even pass? I have a HMF now and that thing is LOUD!

[becci4]

every one will be tested. 2-strokes 99db & 4-strokes 97db

[blholtz]

How are you supposed to know how loud your pipe is before you get there?

[Ichoptop]

get it tested locally...but you will probably have to pay for it. (unless you have a cop as a friend)

[motochamp250]

I'm j/w, what is the reasoning behind the db limit? I mean i understand if this was like a big trail ride or something, but this is closed course competition.. what does it matter if someones pipe is 105 db's for the 2 day event? i guess i just don't understand the reasoning being that it is closed course racing... again, i'm JUST WONDERING..

[motochamp250]

also, in amature classes can you get tested after the race like the pros could? so if you put a pipe on for the test then swap for the race can they still check you after the race? j/w

[dennis45]

THEY MARK THE APPROVED EXHAUST , WHEN TESTED .
THE PROS HAVE TWO TEST EXHAUST MUFFLERS. IF YOU BREAKE ONE THE ONE YOU REPLACE IT WITH MUST BE APPROVED. IF WE DO NOT START MAKING OUR ATV 97 OR LESS .WE WELL SOON FIND NO PLACE TO RIDE. THERE ARE PEOPLE WHO LIVE NEAR SOME OF OUR TRACKS.

[blholtz]

Originally posted by Ichoptop
get it tested locally...but you will probably have to pay for it. (unless you have a cop as a friend)

guess that would work if you live in an area that tests for db level in cars. I have a buddy who is a cop and they don't have that kind of equipment that he knows of.

He couldn't even tell me where to get it done.

[slightlybent47]

You can get a db tester at Radio Shack for about $70.00. The trick is knowing what type of setting they are using and at what distance it is from the pipe and if it’s out doors or under a tent. All these things will affect the sound level.
My ex with a WB exhaust is around 115 db at idle and when revved it will peg my meter at over 130 db. And it’s not as laud as some of the bikes out there.
97 db is not very laud at all but if it’s at idle then it may be possible but performance will suffer.

I understand the reason for production bikes sold to come with a quiet pipe, but for closed course out door racing there should be no limit on sound. This where we bring out the big guns and run what you brong racing.

[slightlybent47]

I’ll try to remember to bring my meter to our next race on March 6, and take a survey on how laud everyone is, both while they are on the track and at idle.

[DnB_racing]

Originally posted by slightlybent47
You can get a db tester at Radio Shack for about $70.00. The trick is knowing what type of setting they are using and at what distance it is from the pipe and if it’s out doors or under a tent. All these things will affect the sound level.
My ex with a WB exhaust is around 115 db at idle and when revved it will peg my meter at over 130 db. And it’s not as laud as some of the bikes out there.
97 db is not very laud at all but if it’s at idle then it may be possible but performance will suffer.

I understand the reason for production bikes sold to come with a quiet pipe, but for closed course out door racing there should be no limit on sound. This where we bring out the big guns and run what you brong racing. they usually measure one foot back and six inches to the right!!if you can turn your silencer or turn down pipe to the middle of quad instead of straight back ,, you can get a couple db's lower

[dennis45]

how they do it is in the rule book

[DnB_racing]

the only measurements I could find said 20" and at a 45 degree angle to side.. I couldnt find the rule book for nats

[slightlybent47]

I just tested my ex and here’s how it came out.
Using C weighting at idle with the air blowing strait in the meter and at 6” from opening.
123 db strait
120 db angle
118 db away
Using A weighting at idle with the air blowing strait in the meter and at 6” from opening.
111 db strait
109 db angle
104 db away
Using C weighting at idle 6” from opening and 6” above opening so the air is not blowing on the meter.
120 db strait
118 db angle
116 db away
Using A weighting at idle 6” from opening and 6” above opening so the air is not blowing on the meter.
103 db strait
102 db angle
101 db away
Using C weighting at idle and from 10 feet.
99 db
Using A weighting at idle and from 10 feet.
82 db.

[DnB_racing]

Originally posted by slightlybent47
I just tested my ex and here’s how it came out.
Using C weighting at idle with the air blowing strait in the meter and at 6” from opening.
123 db strait
120 db angle
118 db away
Using A weighting at idle with the air blowing strait in the meter and at 6” from opening.
111 db strait
109 db angle
104 db away
Using C weighting at idle 6” from opening and 6” above opening so the air is not blowing on the meter.
120 db strait
118 db angle
116 db away
Using A weighting at idle 6” from opening and 6” above opening so the air is not blowing on the meter.
103 db strait
102 db angle
101 db away
Using C weighting at idle and from 10 feet.
99 db
Using A weighting at idle and from 10 feet.
82 db. if i tested my ex she would brake the meter LOL...

back on topic ...just curious what exhaust and is there a end pipe??

[rageatvsupermom]

I believe depending on what bike 2/stroke vs. 4/stroke there are different
rpm levels that they are measured, it is not at idle I know that for sure.

[slightlybent47]

I just used that as an example. I don’t know how they will do it.
My ex has a stock pipe with a wb mx4 slip on. It’s not near as laud as some of them.
I do know that with a full gate of pro riders leaving the gate it sounds like a 747 taking off.lol AWSOME!

[slightlybent47]

My reason for doing a test sample is to show how much deference there is in how you do the test. There are so many variables that you need to know exactly how they will do the test.

[mamaknothead]

Wow this sux. I guess not only are they trying to kill us with the back and forth across the the Country schedule now they release that they are gonna sound test 4 weeks before the season starts.

So who has an extra $500 to run out and buy a new pipe 4 weeks before you drive 15 hours to the first race?

What gives,?

[mayno323]

So what after market pipes can actually pass this db test with a full on race motor? HMF quiet race series? Dasa? How much hp loss we talkin?

[slightlybent47]

I wish this was posted last week. I could have some results from last weekend.
If you need to use my meter give me a call, I’ll let you use it.

[#101]

Put a pillow in your airbox

[dennis45]

I THINK IT IS A FIM SPEC. THEY USE AND HOW.

[finsteratv]

Originally posted by #101
Put a pillow in your airbox
??:confused: ??
whats it do

[krt400ex]

Originally posted by finsteratv
??:confused: ??
whats it do

i would take that as a joke, but if he were serious i would assume that it is going to restrict the amount of air going into the engine. restricting the amount of air going in is going to restrict the amount of air coming out, hence making the exhaust note quieter. basically a quiet core, or smaller exhaust tip is only restricting the amount of air coming out of the exhaust. this is how you quiet it.

i personally dont care about sound. i care about if a person is being respectful to the others near where he is riding. the places where i ride, sometimes you go by a house or two. so we just ease up on the throttle and use low rpm. yea, they might hear it, but it isnt obnoxious and aggravating. we dont ride late at night and we dont ride early in the morning. its all about being respectful towards people in the area. the problem arises when you get a 14yr old who cuts the end off his exhaust or runs a straight pipe and pegs the throttle everywhere making as much noise as humanly possible. that is what pisses people off.

i've never had a noise complaint where i ride and yet at the same time, i talk to alot of people who say they hate the noise. my 400ex had a full yosh system, and no spark arrestor. i never had anyone complain about noise, and that quad was loud. my 300ex, WB e series, no spark arrestor plate. never had a complaint. the ktm, i removed the spark arrestor and re jetted it. no complaints. its a matter of being respectful or not.

when it comes to closed course racing, people that live in the area should be prepared for the noise and not let it bother them. i find that most people who have lived in an area all their lives where atv's and dirtbikes are a normal thing, dont care so much. people that move into the area are the ones who tend to complain more. IMO, if you move into an area, look into it before you move. it isnt right to mess with someone's way of life when you are the alien. i dont feel that there should be sound limits on closed course racing. restricting air is restricting power.

[blholtz]

Can anyone link the site thst has this spelled out. I can't find it on atva or ama sites

[GILCO]

They say this every year, Smitty isn't going to check a pipe. I bet he doesn't know how.

[trailrider894]

I honestly don't see how they can do this.... So my Question is what if you are over the limit??? Because i will be driving upwards of 3 hours to the track, and i don't wanna show up there and get shut down because my exhaust is too loud....

[GILCO]

They will give you a chance to get it fixed before the races start.