Quieting Boats down

[Don Ferrette]

So you are the final know all word on induction noise? Wrong answer. Induction noise becomes a bigger part of the equation when you start getting noise levels down under 90, you ain't even close.

No don you get the final word.. I am tired of trying to explain my side.. you win.. when you figure it out let me know..

If you think that i am not trying other options you are nuts.. Like i said you win. no more on this topic.. every time I try to put something you have a reply that i am wrong so i am wrong.. you figure it out.

chris

Chris, this is NOT about getting the final word, but to post such disinformation?? To quote- "anyone that says that the induction noise is a part of it is nuts... i tested it i saw it.. end of story. " is wrong. Induction noise does play a big role in overall noise, maybe not in your particular instance but to say everyone is nuts thinking otherwise doesn't cut it. We've seen repeated cases of 2 to 3 dB drops with the addition of only a cowl in certain applications, biggest being on the mono hulls. You are too hung up on that CMB big belly BOOM pipe, so far your "side" has been you can't get that pipe quiet & I'll tell you this, you won't do it with an add on muffler. And if it comes down to some pipes just won't meet the noise limit no matter what then it's time to try other pipes......

 

[Brian_Nelsen]

Mark

I am not going to answer your question. This post was set up to try to discuss ideas on what can help and what cannot. Your question is better asked in the Noise and DB meter thread.

I will say that the internal stinger does not do the job in all cases. I Have two 90 nitro pipes for my rigger that will not make 92 db with an internal stinger. I have a muck pipe and a cmb pipe with internal stingers. at my site with my testing methods they run 97 for the muck and 94 for the cmb. These are just my personal results in all cases we are discussing ways to reduce the overall noise in a boat. We always tend to focus on the pipe first. I think induction noise is also important as Don has stated. There are many areas which create noise in our boats.

Thanks for your post and the information it contained

Brian Brian, I too ran 13 cc Muck pipes with internal stingers as described by Mark Bullard on my single k-90 hydro and on twin with k-90's. Both boats were over at the Nats. They measured at Huntsville and were 92db. What is interesting my 101 with a MAC 15cc with a rum runner and no cowl was legal at the Nats. Why? I think the reason is that 1] db readings were reading high at the Nats. 2] I think the Muck pipes maybe louder because their wall thickness is greater and maybe reasonnating more than a thin walled Mac pipe.

Doc

I have to agree with you the Muck pipes are much thicker than almost all of the pipes from other manufacturers, I am not sure but I think the material runs a little harder than others as well. I should see if I have any testing equipment at the shop that would show that.

I really like my Muck pipes, thats why I added a can muffler to one to try on my 90 rigger. Went to the pond today to test but the weeds have taken over the course. Guess that will have to wait till after the next race when they clean out the weeds.

Brian

Brian, As mentioned I had internal stingers on the Muck 13 cc and then added rum runners in addition and my twin was still over at the Nats. Then ussing rubber pieces that tuned the exhaust away from the meter I was legal, but by then it would not run well if at all. Doc

Doc

I understand what you are saying, I have tried that on mine as well. Steve Muck used to weld on a can style muffler and I just happen to have one he sent me a while back. I have welded it to my pipe and will try it when I can get open water at our pond. This can muffler is kind of big but it appears to offer little extra back pressure. I will let you know in a few weeks when I test it.

Brian

 

[Chris Wood]

I am hung up on the pipe because it is the best pipe on the market.

You keep testing.. When you figure it out i will by one..

Apperently i know nothing so i will not post what i find anymore..

chris

 

[sport hydro]

Brian,

I am with the Badgers Model boat club in WI. You attended our race in July there. Do you know or remember a boater named Mark Dauer? He has made some very quite can mufflers for all his boats. I know that on his E/F mono, you cannot here his boat(this is with a CMB 90EVO) running when other boats are in the water. His boat is a very consistant running, competative boat and he is always in the top two or three at the end of the day. I have seen the db meter set up per the rules show his boat to be less than 90db's. You might try to contact him and get some input as to how he makes the can add on.

 

[Don Ferrette]

Apperently i know nothing so i will not post what i find anymore..

Come on Chris, that's weak. So what if you have no success with quieting that CMB pipe, are you going to quit racing over it? I seriously doubt it, you'll do what many of us are already doing, you'll bust butt trying to find something that will work. You seem like a smart guy, why not apply that knowledge and be a little more broad based in your approach.

And since we seem to have run right past it I'll say it again- first trial runs with the new prototype pipes on the twin 90 SGX came in at 82dB, A weighted fast response, 25 feet from shoreline with a 10 foot elevation (we have no choice on height off water due to the physical layout of site). These pipes are incredibly quiet & show alot of promise, speed is there but need another full day of testing to nail down the optimum settings. The torque output is very, very strong and I'll need to make some trim changes, the boat kept wanting to stand up on the props when you nailed it. B)

 

[AWaddle322]

I am hung up on the pipe because it is the best pipe on the market.

You keep testing.. When you figure it out i will by one..

Apperently i know nothing so i will not post what i find anymore..

chris

Chris,

It is just the pipe on the market for the boats that you and I run. You put it on a different brand of boat and it does not work so well. Also remember on the induction noise thing our cowls are not made from a piece of ABS ( we will not have to fight some of the things in this area that other will).

Don, Very interesting results with the twin. The only problem is that at 100 feet above water level it is 94 feet to high. when you do the math you are actually 103' from water highth assumming that you are 25' from waters edge. Every time the distance doubles you reduce noise by one db. so in essance your 82 db boats is now 99 db if my math is correct. O and by the way there are ways to make the CMB quite enough from the standard we have today.

Once again I will state that until we get the calabration of the db meter thing straightened out all testing you all are doing is simply spinning your wheels. YOU ARE WASTING YOUR TIME WITH THE USELESS INFORMATION YOU ARE GETTING. It time to find the real cure for this problem.

Allen

 

[Don Ferrette]

Don, Very interesting results with the twin. The only problem is that at 100 feet above water level it is 94 feet to high. when you do the math you are actually 103' from water highth assumming that you are 25' from waters edge. Every time the distance doubles you reduce noise by one db. so in essance your 82 db boats is now 99 db if my math is correct. O and by the way there are ways to make the CMB quite enough from the standard we have today.

Allen, please re-read my results, it was TEN feet elevation not 100. And I do agree with you we need to get meters calibrated to a set standard but theses pipes are incredibly quiet. And I flat out disagree with you saying this is a waste of time. Even if there is a couple dB difference between meters 82dB is still a SUBSTANTIAL reduction in noise.

 

[AWaddle322]

Apperently i know nothing so i will not post what i find anymore..

Come on Chris, that's weak. So what if you have no success with quieting that CMB pipe, are you going to quit racing over it? I seriously doubt it, you'll do what many of us are already doing, you'll bust butt trying to find something that will work. You seem like a smart guy, why not apply that knowledge and be a little more broad based in your approach.

And since we seem to have run right past it I'll say it again- first trial runs with the new prototype pipes on the twin 90 SGX came in at 82dB, A weighted fast response, 25 feet from shoreline with a 10 foot elevation (we have no choice on height off water due to the physical layout of site). These pipes are incredibly quiet & show alot of promise, speed is there but need another full day of testing to nail down the optimum settings. The torque output is very, very strong and I'll need to make some trim changes, the boat kept wanting to stand up on the props when you nailed it. B)

Don,

which is correct 100' or 10' regardless unless you are launching you boat from 10' or 100' you do have a choice.

Put the meter where it meets the rule. if this is in the launch area so be it.

Allen

 

[Don Ferrette]

Don,

which is correct 100' or 10' regardless unless you are launching you boat from 10' or 100' you do have a choice.

Put the meter where it meets the rule. if this is in the launch area so be it.

Allen

HUH?? Allen the meter was appox. 10 feet (maybe 9 feet since the bank is 6 feet high & the person taking the readings was holding meter 3-4 feet up) above the water which is only 4 feet higher than the 4-6' height range the current rule specifies so the readings will be very close. It is not physically possible to be 25 feet back & 6 feet off the water level at this site even in the launch area. :blink:

 

[waltr]

I don't see anyone "spinning there wheels".

This is new to everyone here.It's trial and error and gathering usefull info.

In some instances,it really doesen't matter if the db meters aren't calibrated.

If your boat is running @ 94db with a fat pipe on your un-calibrated meter,you change it to a quiet pipe and now the meter is @ 84db this time,calibrated or not.YOU STILL HAVE A 10db IMPROVEMENT.

Calibration,calibration,enough now.They'll all be done in time.

But that's no excuse to sit on your ass and do nothing! Just use them right now to see improvement.

The calibration really matters most when you're shooting for that 91.9db.

If you see 82db on your un-calibrated meter,I really think when it finally gets calibrated you'll still be legal.

It's time to get with the program and stop all of the lame excuses.

And yes,it will possibly require some new hardware,but that's racin!

And if anyone doesen't believe in induction noise,they're too young to remenber the old Holley Spread Bore carbs.

 

[Henrietta]

Don,

which is correct 100' or 10' regardless unless you are launching you boat from 10' or 100' you do have a choice.

Put the meter where it meets the rule. if this is in the launch area so be it.

Allen

HUH?? Allen the meter was appox. 10 feet (maybe 9 feet since the bank is 6 feet high & the person taking the readings was holding meter 3-4 feet up) above the water which is only 4 feet higher than the 4-6' height range the current rule specifies so the readings will be very close. It is not physically possible to be 25 feet back & 6 feet off the water level at this site even in the launch area. :blink:

We originally got the DB meter out b/c we had some new folks w/questionable boats in the pits and just wanted to make sure we were following the rules. I took random readings during our race yesterday both standing on the dock 6" above the water and at the CD stand 10' above and maybe 5' back - Don's boat never registered above 82DB, and was 88DB when his pitman walked by me to launch. I'm aware of the calibration issues, and the rest of the techno stuff is really over my head so I don't want to get into this debate. . just my two cents for what it's worth.

 

[lohring]

We have spent a lot of time dyno testing the 35cc CMB lately. The engine comes with a giant stinger muffler and the exhaust is quite quiet. However, the noise at the intake side of the engine is impressive. Intake silencers and complete cowling as well as exhaust mufflers may be needed to keep big engines quiet.

Lohring Miller

 

[AWaddle322]

Don,

which is correct 100' or 10' regardless unless you are launching you boat from 10' or 100' you do have a choice.

Put the meter where it meets the rule. if this is in the launch area so be it.

Allen

HUH?? Allen the meter was appox. 10 feet (maybe 9 feet since the bank is 6 feet high & the person taking the readings was holding meter 3-4 feet up) above the water which is only 4 feet higher than the 4-6' height range the current rule specifies so the readings will be very close. It is not physically possible to be 25 feet back & 6 feet off the water level at this site even in the launch area. :blink:

So much for saving ponds. I guess since you cant comply I guess that no more IMPBA events should be held at his pond. No my rule just a rule that need fixing.

Allen

 

[Don Ferrette]

So much for saving ponds. I guess since you cant comply I guess that no more IMPBA events should be held at his pond. No my rule just a rule that need fixing.

Allen

Ya know Allen you're a buddy but it seems the only thing you (& a few others) are doing now is finding any way you can to discredit the rule, incite people to speak against it & ignore factual results people are posting. It's pretty sad that rather than be positive about results of a twin 90 boat that's capable of running 10dB under the limit you've got to nit-pick. Guess you also chose to ignore Christi's (Henrietta) post that even at water level right at the edge of the pond the boat was reading 82dB. That's CLOSER than you need to be which means the boat would read even quieter @ 25 feet back & 6 feet up. This thread was supposed to be about quieting boats down & what we're doing that's working, well guess what?? 82dB measured CLOSER than the rule specifies shows that something here WORKS but a few of you are content to keep bitching about the rule. Fine, you want to ***** more about the rule, go do it on the dB meter thread, not here. This thread is for what we're finding that is working............. :angry:

 

[AWaddle322]

So much for saving ponds. I guess since you cant comply I guess that no more IMPBA events should be held at his pond. No my rule just a rule that need fixing.

Allen

Ya know Allen you're a buddy but it seems the only thing you (& a few others) are doing now is finding any way you can to discredit the rule, incite people to speak against it & ignore factual results people are posting. It's pretty sad that rather than be positive about results of a twin 90 boat that's capable of running 10dB under the limit you've got to nit-pick. Guess you also chose to ignore Christi's (Henrietta) post that even at water level right at the edge of the pond the boat was reading 82dB. That's CLOSER than you need to be which means the boat would read even quieter @ 25 feet back & 6 feet up. This thread was supposed to be about quieting boats down & what we're doing that's working, well guess what?? 82dB measured CLOSER than the rule specifies shows that something here WORKS but a few of you are content to keep bitching about the rule. Fine, you want to ***** more about the rule, go do it on the dB meter thread, not here. This thread is for what we're finding that is working............. :angry:

Don,

If you look very closely I am actually for a noise rule. I am trying to get people to see the faults with the noise rules so we can get a good noise rule. And since your pond cant meet the guidelines of the current noise rule then should you really be allowed to have an event there? Rules are rules!!!!!!!!!!!!! They should not just benifet us when that how someone wants it that way. It was voted on by the members and the members say that with out the distance you dont have an IMPBA Legal site.

For quitning boats down. Look at the dynamics of your cowl. You have a cowl mostly like against some type of wood surface. if you put small dobs of silicoln betweem the cowl and that wood structure you will get quiter. Note you are not glueing the cowl down with silicoln. you are putting silicoln on and allowing to dry.

Also the closer the fitting the cowl the less room there will be for echos.

Allen

 

[John Knight]

Allen,

Be careful about passing judgment on a lake site being capable or legal to hold any races due to the written declaration of the DB rule without first being there. The ODMBA lake is my home lake where I first started my racing career. I have raced there many times and don't ever recall you venturing that far east. You are throwing grenades.

The way the rule is written does not take into count for elevation changes from one site to another and that was BY INTENT. No two sites are identical and to try to fit all into one tight box will not work or have gotten the rule passed in the first place. If you try to do that I will line up first to oppose you as it is the wrong approach. There must be some common sense applied to fit each site. If one site elevation is 2' above water level and another is 6' above level, the difference is so miniscule that it is not worth arguing about. Potentially less than .10 of a db differential, if that, according to my engineers. NOTHING to beef about, PERIOD, regarding the elevation differences! Non-factor so let it go.

As for the validity of the testing Don has done, give him credit for trying out stuff at the lake and trying to find solutions. And others like him. Better than pounding out "solutions" at the keyboard! Some of you are just not willing to listen because you are complaining too much.

 

[AWaddle322]

Allen,

Be careful about passing judgment on a lake site being capable or legal to hold any races due to the written declaration of the DB rule without first being there. The ODMBA lake is my home lake where I first started my racing career. I have raced there many times and don't ever recall you venturing that far east. You are throwing grenades.

The way the rule is written does not take into count for elevation changes from one site to another and that was BY INTENT. No two sites are identical and to try to fit all into one tight box will not work or have gotten the rule passed in the first place. If you try to do that I will line up first to oppose you as it is the wrong approach. There must be some common sense applied to fit each site. If one site elevation is 2' above water level and another is 6' above level, the difference is so miniscule that it is not worth arguing about. Potentially less than .10 of a db differential, if that, according to my engineers. NOTHING to beef about, PERIOD, regarding the elevation differences! Non-factor so let it go.

As for the validity of the testing Don has done, give him credit for trying out stuff at the lake and trying to find solutions. And others like him. Better than pounding out "solutions" at the keyboard! Some of you are just not willing to listen because you are complaining too much.

John,

You know that I would never do anything that would potintial cost anyone a site to run on. Just poiting out a nuther flaw in our rule. And by the way in september 2005 roostertail is clealy states below the rule that the intent of this rule was to be measured approximately 75 foot from the boat and approximately 5 feet from water heigth. However you are correect it is not stated in the rule but it is however the intent.

How come you never answered my questions about what the engineers said on the other thread?

Don, Congrats on your testing. I hope after spending all this money that when we get a real db meter that 82 dbs does not turn out to be96 dbs. We do not know!!!!!!!!!!!! But you did quiten it down some. Is it compliant. who knows.

Maybe our safety director can report his findings on the accuracy of these meters as he has a good meter and that other thing to.

Allen

 

[Don Ferrette]

Don, Congrats on your testing. I hope after spending all this money that when we get a real db meter that 82 dbs does not turn out to be96 dbs. We do not know!!!!!!!!!!!! But you did quiten it down some. Is it compliant. who knows.

Some?? I guess you have no idea what 82dB sounds like .. or should I say doesn't sound like.

 

[Jet Driver]

I hope all of this works. We need to move on to the chemical polution issue we have with exhaust residue contaminating the water.

 

[John Knight]

Allen,

I chose not to answer until I got an answer myself. Most meters are made and calibrated but NOT certified and that is THE key, to the general public. They are made for the general temps we see from day to day. 60 to 90 degrees is the norm but does not mean that they suddenly lose their calibrations or reliability because they don't. Only in temp extremes will they become unreliable unless they are specially built for the military or commercial applications. Your example of 30 degree to 100 degree is well beyond most conditions we ever race at so it is not comparable. They say 65 to 95 still is reliable and they are a lot smarter that you and me, put together.

We have a hitech calibration lab at work and what you contend about the meters being that off in their reliability is "A bunch of crock for a ignorant guy who does not know what he is talking about. We calibrate tech equipment well over 100K for the government for a living and we know what we are talking about." This is in response to some of your comments you have asserted about the equipment, including the cheap Radio Shack units. They have tested them and have found them to be quite reliable. Saying that Don does not have a "real" meter is insulting to him and everyone else. Who gives you the almighty right to pass judgment on him and others to do that?

You keep telling all of us what the INTENT of the rule is because that serves your personal interest. Why don't you stop telling us what the intent was to be. How far was the boat running from the test area? 75' or more? Were you there? Ever been to the lake? How far is the buoy line from the shoreline? 50? 75? 100? 125? Or even 150? Rulebook specifies it can be from 50' to 150' from the shoreline. How are you going to test the 150' line from the shoreline? In the water? Not in our lake you won't. Let's get real. These are recommendations only because each site is unique - PERIOD! You yourself said the level should be APPROXIMATELY 5' above water level. Dictionary time.

It is quite apparent to many of us that even if some quantifiable technical data is presented, some, including you, will not accept it. Too bad. Turn your energy into something positive for this. Take a look at this thread subject. Stop slamming people that are trying to help. You are not.