IMPBA noise rule & dB meters

[Don Ferrette]

Don, the problem I see with stationary testing is that the motor may be rich and may not reach full rpm. I had put some thought into this and it makes since that a motor that is not loaded will not be working as hard a make as much noise.

Also with the Evansville pond being rock throwing distance to the interstate the back ground noise changes alot. I reaaly believe the board of IMPBA SHOULD GIVE SOME DISCTETION TO THE HOST CLUB until we learn more about qll of this.

Allen

Yes Allen that is a point to consider but if you give the CD discretionary power he can have the boat tested as soon as it's brought in & not "tweaked down". As a CD or race official I for one would have no problem telling someone on the test stand to lean it up & let it rev if you want to keep racing.

And the interstate being there is not part of the peak noise level. A dB meter knows only one thing, what the loudest sound is/was. So unless that interstate measured out at over 92dB with no boats running it's not a factor. I think the two biggest factors were a totally unforgiving site offering zero sound bleed off & meter calibration issues. Like Dave Marles said 92dB is actually still loud. :blink:

 

[Brad Christy]

Guys,

Just like the troubleshooting page in your VCR manual (is the unit plugged in?), I'm going to ask a stupid question:

Were all the SPL meters set on the same range setting?

I run sound for a friend's band, and we use a SPL meter (NOT a RadioShack cheapie) to set the stage volume so the mic's are always driving the mixing board consistantly. Since the knob that sets the range is also the power switch, it could be VERY easy to simply turn the know to the wrong setting. Since I don't know which meters were in use at the Internats, this may not even be an issue, but I thought I'd ask.

Also, what has been said about the SPL reading no being the whole story is very true. I was just at the Celina, OH race, where there were ZERO noise infractions, accourding to those in charge of the SPL meter. Believe me, I'm not trying to stir up any big mud puddles with this, but there were lots of gas boats in attendance, every one of them louder (by ear) than ANY nitro boat there. What the ear percieves as loud, may only be signs of a lower tolerance to a particular frequency. The opposite can be said for those who have already mentioned some hearing loss in the higher frequencies, thinking the smaller engines are not as loud.

Chris,

If you're looking for something to try, I've been running an OPS 3280 with an internal stinger muffler with considerable success. It is legal, effective and (as far as I could tell) had little or no impact on the pipes performance, good or bad.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Tim_Duggan]

Correct me if I'm wrong, but wouldn't your competition have the same perceived handicap of having to run a different pipe to their current choice? It's no handicap if EVERYONE has to comply to it.

By the very nature of competition, it wouldn't take long at all before people work out what pipe works in terms of performance as well as remaining compliant to a noise limit. I can even give you an example!

There are 2 guys here in my area who are going to the NAVIGA world champs this year and have been racing locally with pipes that are compliant to 80dB, even though we have a 90dB limit in Oz - and funnily enough - they are just as competitive as before they switched to these extremely quiet pipes, because they did the testing and found a set-up that gave them results.

I fail to see why people differentiate a boat being too loud, to say (for example only) using an oversized engine. It's not a matter of performance difference - it's a case of breaking a rule!

Almost every form of motorsport has some sort of noise limit in place, for a reason. Loss of venues because of excessive noise complaints. Loss of a venue also hurts the people who are prepared to make an effort to reduce noise, which hardly seems fair in my opinion.

IMPBA has one huge advantage in this whole issue - they can see what has worked for other similar organisations and implement accordingly, rather than having to resort to trial and error.

 

[Mark Poole ModVP]

Does anybody here know any weapon systems liasons? (Nice way of saying arms dealer) Maybe they could share some declassified sillencer info with us. Crap, if you can silence a 50 caliber I am sure it would help an RC boat pipe.

 

[Rudy Formanek]

The Japanese have been running boats similar to US boats but with a much longer add on muffler ( kinda like a streached Prather add-on, like triple the length). Probably would quiet any offensive boat to US standards, but would not make it meet the European standards. Going by the Euro's methods are probably overkill for us right now, it might be best to examine what the Japanese are doing. Rudy

 

[Piston1]

We got to go back to the beginning. IMPBA should separate from this noise issue and allow it to be handled at the local level. Publish guidance and recommendations, not rules. The original intent was, "control noise to help clubs keep racing ponds etc". That could only be done locally. If a 21 engine annoies you then step away or wear ear plugs. If you don't like a particular place because it is to loud, then don't go. Ultimately I bet you will go because we all are looking for the competition not the quiet place.

 

[Joe_Knesek]

Don, the problem I see with stationary testing is that the motor may be rich and may not reach full rpm. Allen

Allen, the SAE guideline used by the AMA actually addresses this issue by measuring EGT. I'm not sure we want to go that far but maybe the inspector makes determines if the motor is overly rich. I think the stationary testing also addresses the fact that our hearing isn't being damaged once the boats are on the pond. It's happening while the boats are being started in the pits. That's why you were sticking your fingers in your ears when the twins were being fired up! :huh:

 

[RIGGERMORTISE]

Correct me if I'm wrong, but wouldn't your competition have the same perceived handicap of having to run a different pipe to their current choice? It's no handicap if EVERYONE has to comply to it.

By the very nature of competition, it wouldn't take long at all before people work out what pipe works in terms of performance as well as remaining compliant to a noise limit. I can even give you an example!

There are 2 guys here in my area who are going to the NAVIGA world champs this year and have been racing locally with pipes that are compliant to 80dB, even though we have a 90dB limit in Oz - and funnily enough - they are just as competitive as before they switched to these extremely quiet pipes, because they did the testing and found a set-up that gave them results.

I fail to see why people differentiate a boat being too loud, to say (for example only) using an oversized engine. It's not a matter of performance difference - it's a case of breaking a rule!

Almost every form of motorsport has some sort of noise limit in place, for a reason. Loss of venues because of excessive noise complaints. Loss of a venue also hurts the people who are prepared to make an effort to reduce noise, which hardly seems fair in my opinion.

IMPBA has one huge advantage in this whole issue - they can see what has worked for other similar organisations and implement accordingly, rather than having to resort to trial and error.

We have been working with diferent muflers for a long time now and I know how quiet they can go without afecting performance, But as it has been said in this post the exhaust is only one part of the noise. As far as i know our pipes will probably be on some boats at the world champs so they have to confirm. we are continually developing new mufler systems and the all work but most will only work at certain rpm ranges!

as a manufacturer of pipes we are committed to racing and running quiet boats, planes and cars.

recently testing the new gas pipe it ran 82 and 84 db consistently! not bad for a gas boat!! But we cant quote this as acurate figures because we used a cheap db meter. I am very happy to see the limit being enforced, and sorry for the people who got DQ'd but nows the time to move on and get something done.

Dave

 

[Geraghty]

We got to go back to the beginning. IMPBA should separate from this noise issue and allow it to be handled at the local level. Publish guidance and recommendations, not rules. The original intent was, "control noise to help clubs keep racing ponds etc". That could only be done locally. If a 21 engine annoies you then step away or wear ear plugs. If you don't like a particular place because it is to loud, then don't go. Ultimately I bet you will go because we all are looking for the competition not the quiet place.

Jose,

No,lets just go back to the beginning of this thread.This is not about whether we should have a noise rule or not.

Whether you or I like it ,the membership has spoken.The noise rule is in place.

I started this thread/discussion to get input on how to administer the noise rule.

The events at Evansville clearly showed we have flaws in the administration of the rule that we currently have.That is what this is about.

It is no secret what side of the fence you stand on in this noise debate and I respect that but that is not what we are talking about here.If you want to start the pissen match again,please do it in another thread.

Rod Geraghty

 

[Scott Norris]

There are 2 guys here in my area who are going to the NAVIGA world champs this year and have been racing locally with pipes that are compliant to 80dB, even though we have a 90dB limit in Oz - and funnily enough - they are just as competitive as before they switched to these extremely quiet pipes, because they did the testing and found a set-up that gave them results.

What pipes? I haven't seen anybody mention a name brand for any particular pipe that will run at the NAVIGA 80db standard.

 

[Piston1]

Rod I respect your opinion, and I am one of those that tries and will comply with the rules. I wear quiet pipes on all my big block engines. I just don't see an affordable way to consistently enforce the written rule or any variation that requires level measurements. It should be handled locally.

 

[Grimracer]

mufflers this and DB meters that.... this will go on FOREVER..

GET IT IN THE HANDS OF THE MFGS....

Have the MFGs submit pipes to IMPBA (say one time a year with a 3 month window to get it approved)

Have an expert test it.. A team like John Finch, Ron JR and Steve Wood.. Or whomever...

Give it an approval or not.. (not sure how to do this but we are smart people we can figure it out)

Give the pipe a part number

Approved pipes are listed in the rule book

You run that pipe.. or any of the approved pipes and you toss the DB meter in the lake.

What you get is a stronger marine modeling through MFG support and less bickering at the pond.

Grimracer

 

[Don Ferrette]

mufflers this and DB meters that.... this will go on FOREVER..

GET IT IN THE HANDS OF THE MFGS....

Have the MFGs submit pipes to IMPBA (say one time a year with a 3 month window to get it approved)

Have an expert test it.. A team like John Finch, Ron JR and Steve Wood.. Or whomever...

Give it an approval or not.. (not sure how to do this but we are smart people we can figure it out)

Give the pipe a part number

Approved pipes are listed in the rule book

You run that pipe.. or any of the approved pipes and you toss the DB meter in the lake.

What you get is a stronger marine modeling through MFG support and less bickering at the pond.

Grimracer

Not a bad idea ............ maybe on paper ............... except as soon as someone starts "modifying" the pipes then what? How are you going to police that?? It will take longer to check suspect pipes than any dB test, be it stationary or otherwise. I can see the ruckus being raised already when you tell someone to remove the pipe for inspection because you think it's been tampered with. A way to spot check has to be there, no exceptions. As long as there are rules there will be people who will try to skirt, exploit or just plain cheat, sorry but that's the way it is when you have "competition". Also, did a manufacturer come up with internal stingers on marine pipes? No we did & in many applications they work extremely well but that is not a "manufactured pipe". Do you have any clue how long it will take a manufacturer to produce pipes to our needs, IF they do it at all?? NO pipe manufacturer is going to tool up for a new pipe unless it will be PROFITABLE!! What if a boater comes up with a way to get his boat to say 85dB but he made it himself, are you going to tell him he can't run because it's not a "manufacturer's" pipe?? We've already been down the "approved list" before & it don't work, that is why we are where we are now. The previous muffler rule stated an "approved in writing by the IMPBA Technical Committee" muffling device had to be used, I never saw one "approved list" ever but did see everything from legitimate mufflers to rubber balls hanging off the backs of pipes.

This nut can & will be cracked & I plan on starting stationary noise measurement tests this weekend to see how viable this test option is. B)

 

[Steve P]

I agree that we need a better understanding of how to check dB levels. But lets not lose sight of the fact that 90+ % of the boats at the Nats were under the dB level. It is not if we can quite the boats but if we are willing to. If we set our boats up well under 92 then the variablity of the metter will not matter.

 

[lohring]

I have been at races where European racers ran their riggers against American boats. The biggest difference was the noise. One of the fastest boats in our club is a MAC 84 powered Eagle running Andy's quiet pipe. It is also one of the quietest boats. As Dave Marles says, meeting the noise limits just takes some work on the technical details. It's not about the details of meters and measurement techniques. I commend the IMPBA for its stand even though enforcement is painful.

Lohring Miller

 

[Geraghty]

There are 2 guys here in my area who are going to the NAVIGA world champs this year and have been racing locally with pipes that are compliant to 80dB, even though we have a 90dB limit in Oz - and funnily enough - they are just as competitive as before they switched to these extremely quiet pipes, because they did the testing and found a set-up that gave them results.

What pipes? I haven't seen anybody mention a name brand for any particular pipe that will run at the NAVIGA 80db standard.

We saw one this week at Evansville.Bobby Heimel[sP] from Tidewater ran a CMB Naviga pipe on his 1.0 CMB and I am here to tell you it was whisper quiet and the boat was fast.

They may even have them for different size motors.I don't know.I didn't ask.

Tidewater and Stu Barr have the big motor pipes in stock.

 

[Jerry Wyss]

I sure didn't like hearing about the event you had to endure Rod but where man, machine and devices

come together, mistakes are often made.

I was just wondering that if the db devices were in place and operating when open water as going on?

Having never participated in a National Event, I'm somewhat ignorrant of that particular aspect.

I seems to me that allot of the offending boats could have been caught right there and many test readings

could have been done to reveal any inaccuracy's before it cost someones standing in the actual event.

Just a thought I had to type.

EDIT:

Ok, I read it in the very first post. Probably the main reason I don't compete in a National Event,, don't pay attention.

 

[DaveMarles]

I agree that we need a better understanding of how to check dB levels. But lets not lose sight of the fact that 90+ % of the boats at the Nats were under the dB level. It is not if we can quite the boats but if we are willing to. If we set our boats up well under 92 then the variablity of the metter will not matter.

That sums it up perfectly.

There are a lot of issues with noise measurement such as placement of the meter, who reads it, meter calibration, ambient noise, number of boats in a race (noise is accumulative) etc etc but the bottom line is that its not difficult to go under 92 and I'm sure no special pipes are needed. Add on mufflers may help but they need to be big. Better to have some kind of built in silencer and take care of the detail things I mentioned before. Silencing does not kill performance providing the backpressure in the pipe remains the same and this may require bigger stinger i.d. but this is simple technology.

Dave

 

[Steve P]

Yes the dB meter was being used during open water on Sat.

 

[AWaddle322]

You all that keep talking about your 80 db limit must reaaly be doing something different. there were some electric boats there that were at 86 db's. Know how do you get that much quiter than an eletric boat?

I personnally do not care what the noise limit is, all I want is a way to test this before I get some where and find out that there db meter reads different that what I have been using. I understand there will be fluxuations from pond to pond but I would not expect a fluxiation of more than 2 db's. What this whole discusion with me is about is 4 meters set and the same scale and the same response having a variance of 5 to 6 db's at the same site side by side. I have no way of knowing if Evansville meter was correct or Jon Equi. If Evansville meter is correct I am 2 db over if Equi's is correct I am 4 db under and if it is somewere between i would be in the 91 db range at an unforgivving site.