IMPBA noise rule & dB meters

[Don Ferrette]

if you do much recearch into noise you will see that it is not the five minutes of exposure at the dbs we are talking about that hurts your hearing it the all day exposure that hurts your hearing.

After many years of sitting in CD chairs & even just attending races it's nice to go home without my ears ringing for the next couple days. The exposure is culmulative, the damage still gets done, ask someone like Tony Jacuzzi how his ears are now. Are we going to have problems & issues along the way to running quieter? You bet yur *** we will but it can be done. As said previous, I've seen it with my own eyes when myself & others got the opportunity to race against a couple of NAVIGA hydro champs from Norway. They gave us all the competition we could handle & they did it @ 80dB!

 

[AWaddle322]

Allen go back and re-read the whole context of what I wrote, specifically the second part. By the way it is "Calibration", not "Calabration". I have always voted "NO", did you vote.

Jose,

I do understand specifically what you are saying. I am trying to educate others by giving them the information they need. The more I learn the more it looks like db meter are going to be a waste. if you read some of the testing procedures for motorcycles found here http://www.thumperfaq.com/sound.htm you will see that nothing is to be within 16 feet of the meter because something like a tent can cause a harmonis which cause a vibration that effects db meters.

One thing I am curious about last year the meter was to be used between the starting line and buoy 1 and then when the proposal cam out it was mysteriously moved. Why did this happen.

So far as spelling of Calibration what can I say. I guess i am just a dumb old redneck from TN that cant spell much of anything ( i do good to find my way to work most morning you no)

Allen

 

[Brian_Nelsen]

Allen

I for one am not a spelling bee contest winner, I hope people do not hold that against me.

As far as the position of the meter goes I am not sure about how that got changed although I only ever heard it the way it is now. As far as the motorcycle thing goes, thats what I am talking about I have passed and failed with the same exhaust and its stock. Now I have replaced the stock set up with a quiter one and I pass all the time. Not sure why they usually pick on the fat man to test during thier ramdom testing.

There are issues that I have found with where the person using the meter stands and other items around it. Like all the tents around the pond in my opinion have an effect and it seems to be bad. Either way we all have to live by the same rule and in motorcycles its fix it or you do not race period.

Hey I just checked out my meter and it has a self calibrate feature on it.

Funny how that works.

Brian

I hate to say it but this very topic is PART and i say PART of the reason that nobody has signed up to run the 07 nats..

just wish there was a solution to this.

chris

This question is for bill zuber..

Correct me if i am wrong.. At the board meeting the week of the nat's steve cooper was contacted by someone ( i am not sure who ) that is on the board of the impba and was asked to come to the board meeting to discuss the DB situation. And sat there for the whole night was not asked a question regarding this nor able to speak about it..

Like i said correct me if i am wrong.

Just curious about this since steve is a manufacture of nitro pipe's and was asked to sit in on this, why not let him speak his opinion.. ??

if i have misunderstood this i applogize.. this was info that was passed along to me.

chris

Chris

I believe it was myself that asked Steve to make it to the meeting. It was a shame that he had to sit there all night and not get to talk. It was decided that in the interest of actually talking about the situation that the discussion be held in executive session. That means all non board members must leave. Again I think I was the one that told him to come.

So if you want to hang someone I am the guy.

Brian

 

[piper_chuck]

Jose,

I do understand specifically what you are saying. I am trying to educate others by giving them the information they need. The more I learn the more it looks like db meter are going to be a waste. if you read some of the testing procedures for motorcycles found here http://www.thumperfaq.com/sound.htm you will see that nothing is to be within 16 feet of the meter because something like a tent can cause a harmonis which cause a vibration that effects db meters.

While the position of the meter, what's around it, etc is certainly important, let's not lose sight of something. If you've got 100 boats and 97 of them consistantly test a couple db below the limit but 3 are consistantly over, it's pretty clear that the meter calibration or setup is not the problem. While the meters may not be perfect, they can do a pretty good job of quantifying what people on the shore probably already know, someone's boat is pushing, or has gone over, the noise limit.

People who insist on pushing the limit, perhaps aiming for 91.9 db, ARE going to have trouble. People who choose to be conservative, perhaps aiming for <90 db, will have no problems. IF someone running a race suddenly finds that 97 out of that hypothetical 100 boats are over the limit, especially when the perception on the shore is that these 97 are under the limit, it's time to start questioning the calibration of the meter.

 

[Don Ferrette]

I think it's interesting how some of you will scan the internet for this stuff & then "cherrypick" only the info that supports the anti-meter/anti dB limit arguement. Why was it not mentioned how the limit for those motorcycle tests is an EPA mandated stationary test SAE J1287 with a max of 96dB measured from twenty inches away! Also the section about nothing being near the meters says this & I quote- "No one should be within 10 feet (3 meters) of the vehicle other than the rider, the sound meter operator, an assistant to hold the front of the vehicle (if needed) and one other person directly behind the sound meter operator (if needed). The test area should be a flat, open surface free of large sound-reflecting surfaces within 16 feet (5 meters), such as parked vehicles, buildings, signs, and hillsides". They are referring to big things like cars & buildings, not some open area 8x8 pop up tent. Like Chuck said, as long as some of you continue to think what is the bare minimum I can do to squeak under the limit you will continue to have problems. At the last race I attended I found out that my twin running on that particular pond is louder at part throttle (& too loud) than at full speed. Wierd for sure, but I ain't bitchin', I'm now testing different pipes as I want the boat quieter regardless & I've set a goal of 85dB by season's end. Yes it may be tough to attain but I'm damn sure gonna try. What's wrong with thinking how low can I get it? :blink:

 

[Chris Wood]

Chris

I believe it was myself that asked Steve to make it to the meeting. It was a shame that he had to sit there all night and not get to talk. It was decided that in the interest of actually talking about the situation that the discussion be held in executive session. That means all non board members must leave. Again I think I was the one that told him to come.

So if you want to hang someone I am the guy.

Brian

No need for that brian,

I am just curious.. Since this is a HUGE HUGE issue that nobody has a really good anwser for, why didn't we at least take the time to hear from a man that makes pipe's.. That has been my hole grip about this the entire time.. We as a organization, made the choice to make a rule when VERY VERY few people make a product that will pass.

I know, some people out there will reply, there are other ways to do it.. Well i really don't know how to stuff a AIR BOX over the carb and fit it into a boat. so i have to look at the pipe side of it..

I feel this is going to be a on going thing and never get the problem fully cured...

Don,

You said you raced with the naviga guys.. what were they using?? i am interested in finding out , I would like to give it a try what ever it is..

We made a muffler last year.. the insides looked like a magnaflow muffler.. it had walls ... it worked great for sound.. but the boat wouldn't run in the heat.. to much back pressure..

I will say this, we made a muffler for my 20 hydro several years ago, and it covered the entire back half of the pipe up to the tail section.. it made a huge difference.. so my next question, is the majority of the noise comming from the inside of the pipe.. or is it ressinating ( how ever you spell it ) from the out side of the pipe..

My only problem with this is i look at scale boats.. some are quiet some are REALLY LOUD.. and they have a cowl the covers everything..

So i am back to square one..

chris

 

[Don Ferrette]

Don,

You said you raced with the naviga guys.. what were they using?? i am interested in finding out , I would like to give it a try what ever it is..

We made a muffler last year.. the insides looked like a magnaflow muffler.. it had walls ... it worked great for sound.. but the boat wouldn't run in the heat.. to much back pressure..

Chris-

The two NAVIGA guys were Kjell Noddleland & Tore' Hilde, both very fast hydro guys. Me & (John) Finch had our hands full in 60 & F hydro as did others in the 20 & 40 hydro classes. They both ran CMB90's in the F class boats with readily available (everywhere else) CMB muffled pipes not sold over here, only because there was, at the time, no demand for them but perhaps now there will be. I can tell you they were quiet enough that when I was talking to Tore' & a couple other folks, Kjell fired up his 90SG about 10-12 feet away & nobody had to talk any louder to be heard. Last week I had an interesting conversation with a pipe manufacturer who told me they can make marine quiet pipes to work quite well & that a number of years back they were well on the way to doing so but when the OPS muffled pipes were imported into the states & they didn't work worth a crap because they were rather undersized by application, it killed the marine muffled pipe market as everyone assumed muffled pipes didn't work. I had no problem at all believing this about the OPS pipes being too small as back when I ran my 45 Roadrunner with a hot CMB the best pipe was the OPS 60 pipe!! One thing to keep in mind is that if you try to squeeze the noise out of existing non muffled pipes you can & will create heat & excessive back pressure. The distance the sound has to travel also plays a big part in noise reduction & if you look at the European pipes that meet the NAVIGA requirements the all seem to have one thing in common, they are long, they make the sound travel farther before it exits the pipe. This allows you to space out baffling farther so the increase in back pressure is not so dramatic, something else to keep in mind.

 

[Geraghty]

Don,

You said you raced with the naviga guys.. what were they using?? i am interested in finding out , I would like to give it a try what ever it is..

Chris-

The two NAVIGA guys were Kjell Noddleland & Tore' Hilde, both very fast hydro guys. Me & (John) Finch had our hands full in 60 & F hydro as did others in the 20 & 40 hydro classes. They both ran CMB90's in the F class boats with readily available (everywhere else) CMB muffled pipes not sold over here,

Chris,Don,

Bobby Himel [Tidewater] ran a CMB Naviga legal quiet pipe at Evansville and it was hot and the boat ran great......Chris,If you recall,I am sure you saw Bobbys "F" boat run with that pipe.

Back pressure or no back pressure,Bobbys boat ran very fast and very quiet.

Art McMeans told me in Evansville that Tidewater has those CMB .90 Naviga quiet pipes in stock in Bastrop.

Rod Geraghty

 

[Don Ferrette]

Rod, when Kjell & Tore' were over here at that time those were not in the U.S. due to no demand. This was a couple years back.

 

[AWaddle322]

I think it's interesting how some of you will scan the internet for this stuff & then "cherrypick" only the info that supports the anti-meter/anti dB limit arguement. Why was it not mentioned how the limit for those motorcycle tests is an EPA mandated stationary test SAE J1287 with a max of 96dB measured from twenty inches away! Also the section about nothing being near the meters says this & I quote- "No one should be within 10 feet (3 meters) of the vehicle other than the rider, the sound meter operator, an assistant to hold the front of the vehicle (if needed) and one other person directly behind the sound meter operator (if needed). The test area should be a flat, open surface free of large sound-reflecting surfaces within 16 feet (5 meters), such as parked vehicles, buildings, signs, and hillsides". They are referring to big things like cars & buildings, not some open area 8x8 pop up tent. Like Chuck said, as long as some of you continue to think what is the bare minimum I can do to squeak under the limit you will continue to have problems. At the last race I attended I found out that my twin running on that particular pond is louder at part throttle (& too loud) than at full sound. Wierd for sure, but I ain't bitchin', I'm now testing different pipes as I want the boat quieter regardless & I've set a goal of 85dB by season's end. Yes it may be tough to attain but I'm damn sure gonna try. What's wrong with thinking how low can I get it? :blink:

Don,

Also notice that the db meter should be hand held. If you do a whole lot more reeasearch on the subject you will find. this is because under some circumstance a tripod or that tent that uses thin wall aluminum tubing will put out a vibration that we as humans cannot hear but the db meter does pick up on.

I am neither for or against db meters. If we are going to use db meters as part of our racing we need to understand them. There is a problem with the way the rule is written:

Things that change the readings:

Meters surroundings

Tempature

humidity

wind direction

wind speed

on tripod or not on tripod

the best meter on the market that I have been able to find has + or - 1.5 db accuracy.

Also Don with your 85 db goal. i would just like to point out that at the nats this year between 4 meters there was a 7 db discpecy. You may not be as legal as you think you are at 85 dbs.

I for one went to the nats with a boat that had been at 87 to 88 dbs everywere it had been tested and and was at 94 at the nats. There was a couple of boats that had been to Evansville the week before and were legal and were given warings the following week and had o make changes. THERE IS A PROBLEM WITH THE TESTING PROCEDURE THAT IS CURRENTLY IN PLACE1!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Allen

 

[shoboat]

Rod,

I am testing one of the newer CMB 90 quiet pipes on my 101 this weekend, I will report

how quiet and what kind of performance that I get on Monday. I can get plenty of the

CMB 90 quiet pipes for those that would like to try them out. Quiet is the way to go for

the future in Model boating.

Have Fun,

Mark Sholund

 

[teddyd]

TAKE A LOOK AT THIS SITE ON MEASURING SOUND LEVELS.

THERE ARE A LOT OF FACTORS THAT GOSE INTO GETTING PROPER READINGS

http://www.bksv.com/pdf/Measuring_Sound.pdf

 

[Brian_Nelsen]

Teddy and basically all of you.

It is true there are many varables at play with regard to sound. People, tents, tripods etc add variables to the process. In my humble opinion all we can really do is try to come up with a method that works in most cases. We will never come to a perfect solution with so many variables. Some variables we can control some we can't we need to find the ones we can control and eliminate them if possible.

I will read all I can about the subject and do some testing with regard to the current rule to see if we can make it work. I will in the near future be asking some clubs (volunteers any one) to try some things and report back to me if possible.

Again I am no Doc Turner (he is probably smarter than I will ever be) but I can at least do someting.

Chris Sorry I forgot to put the smiley face with my comment. I did have a long coversation with Steve Cooper about pipes and wanted him there in case it came up. Steve is a wonderfull man to talk with and is very open and giving.

Lets keep trying to move this issue forward.

Brian

 

[RaceCraftBearings]

Have you ever heard the expression "On any given Sunday" yes it was said about football that any team can win on any given sunday but in the case of Db you can be fine at your local pond on Saturday and then go back on Sunday with the meter in the same exact spot and having changed nothing about your boat and be over. What changed? You get 3 guesses............

 

[teddyd]

THE ENVIRONMENT!

 

[Chuck Spragg]

THE ENVIRONMENT!

Dang Teddy your smart...

 

[Brian Schymik]

I have noticed something here that noone has really taken into account........

Allen Waddle said ......

Things that change the readings:

Meters surroundings

Tempature

humidity

wind direction

wind speed

on tripod or not on tripod

the best meter on the market that I have been able to find has + or - 1.5 db accuracy.

There are of course many variables...

there are just as many, if not more, variables that affect engine /boat performance. We adjust for them at each and every race site we attend. A different prop here, a different glow plug there... this list goes on and on.

The point is that there will never be a rule that will take into account all of these variables. We adapt at each race for our boat's performance...maybe we will have to adapt at each race for our sound too...Just another variable!

Brian

 

[Mark Bullard]

Well I think that I have readed enough. I am the other person that was DQ at the Internats in the F Hydro class. I did everything that I could do to comply and with no results. When it was all over with I had burned a piston in one of my motors. Now I have heard a lot of things said about this Internats and saw a lot of things also. On Monday when I was ask to run my F Hydro by itself I still busted 96dB with a boat that has always been 90dB or below at many different race sites. And the point was to make a major witch hunt. I was told that I had never tried to comply and that I had never bought any type of muffling or quiet pipes. Well I am sorry if I can weld medals together and try different things to run quiet with my pipes. But to say that I have never tried to comply was wrong. I watch the dB meters a lot that week and saw a lot of boats over the limit and they were not DQ. I guess Ron statement was pretty close "On Any Given Sundy".

I fought against this last rule from the start because it could not be done in a proper way. It had nothing to do with the limit of 92dB. But the witch hunt it would cause and of course I was one of the first to get it.

Now Brian has made a lot of statements on this subject and none of it has any merit as for as I am concern. He sat in the board meeting and laugh about the proposal that I had made to step back and supend the present rule for a few months and to form a committe to fix the problem. The proposal died on the table with no second. Then they wanted to make up a committe at this time to work on the problem and it did pass but no one want to head up the committe including him. Now he says he is working on the problem. I don't think so. He did not even say anything to the host club about the retrive boat going out to stop a running boat. He saw it along with a lot of other people. One of the major problems is the Board is made up of mostly small/motor boat runners. And so the noise problem does not affect them that much. They got there limit down there were they would not have to run muffling devices or quiet pipes and so they can just say screw the big motors. And I can assure you that there was no one in that board meeting that wanted to fix the problem. Now I have drawed my line in the dirt does anyone want to step over it.

Now with all of this said. I am running a committe to fix this problem and the people that I have ask are good people. And we will fix this problem. Why because I believe in IMPBA and I do believe in making boating stronger.

Mark Bullard

District 5 Director

 

[AWaddle322]

I am running a committe to fix this problem and the people that I have ask are good people. And we will fix this problem. Why because I believe in IMPBA and I do believe in making boating stronger.

Mark Bullard

District 5 Director

This is what I wanted to hear. Someone on the IMPBA board trying to find a sloution. If you need any help let me know.

Sincerely,

Allen

 

[Chris Wood]

One of the major problems is the Board is made up of mostly small/motor boat runners. And so the noise problem does not affect them that much. They got there limit down there were they would not have to run muffling devices or quiet pipes and so they can just say screw the big motors

mark you hit it on the head,

if you need any help let me know.

chris