Fluid balancer / driveline coupler

[swatski]

A question about a coupler, Vibratech, fluid balancer.

Does anyone know if Vibratech style fluid balancers / couplers are manufactured/offered for our boats anywhere? They have a steel ring floating inside, really ingenious.

Here is an old pic from somewhere:

And how it works:

Basically, a vibration reducing coupler that works? Yamaha claims to use something new in the couplers for their new “quiet ride” 2015-on boats, but it is hard to figure out exactly what they do, the part numbers did not seem to change. Vibration noise is the number one complain about our boats and many including myself would pay good money to help attenuate it. I’m not so much concerned about increasing the strength, but the VIBRATION REDUCTION.

 

[txav8r]

I don't know a thing about that. I had not heard that they used something new in the "couplers" in the newer boats, just that they were quieter, with sound deadening and some other sound improvements. Any link to where it mentions the coupler in that conversation? I would like to read it. Anyway, can't add anything to the conversation, other than I think noise is also a factor as much as vibration. And I am not certain I would pinpoint vibration as the source of noise. Seems to be exhaust noise to me, and our exhaust is out of the water, and the exhaust section and waterbox are exposed, so I suspect improvements in those in the 2015+ boats. I will follow!

 

[swatski]

From what I understand and hear from Jerry Gaddis/Greenhulk, Yamaha has not made any major changes to the coupler system. They only re named it with a fancy name "quiet ride", might have changed the material to manufacture the damper (rubber part).
Here is a quote about the "quiet ride", same as in boattests etc.:
http://www.personalwatercraft.com/m...nnovations-in-its-sport-boat-lineup-1283.html
(Yamaha is) " introducing a new coupler material in the link between the engine and driveshaft".

Not clear to me what is it they actually did, if anything, with the coupler?

These Vibratech couplers were produced and used in some of the older skis a while back, and recommended as one of the Group K mods for racing boats, not so much for noise reduction but to preserve crankshafts.

I have followed the advise of many here and put some 250lbs of deadening materials into my 190, including wrapping up the water boxes, similar to what
@dan144k has done. It helped, a lot, but not enough. And vibration through the hull is not doubt in my mind a big component of the noise pattern. Easier to combat during manufacturing process, which is basically what Yamaha has started doing.

But, the coupler damper would be a big step in reducing noise and vibration IMHO. There is a lot of weird harmonics emanating out of the 1.8l engines...

 

[Cobra Jet Steering LLC]

Intake and exhaust are the two main areas for noise. I was thinking they may have changed the rubber between the coupler blades also but that is just a guess. I know we have several plastic baffle boxes on the exhaust systems that help reduce noise but I can't speculate just how much they help.
Sea doo had two mufflers and rubber wraps around them on the 4 stroke skies that I had years back, those made a difference.
Honestly I just don't see how the coupler would quiet things much. My feeling is if they had them available and someone tried them it would most likely end up being a big waste of a lot of time, effort and money with little or no difference in sound.
I would suggest looking at something like this for vibration reduction http://www.yanmarhelp.com/i_mounts.htm

 

[txav8r]

HA HA! Try a 230 with MR-1 engines, the 240 is significantly better IMHO. But it turns slower too. I have no idea about the 190/192...but I wonder about loss of performance if adding that kind of weight. I haven't, nor will I add all of that sound deadening material to my boat, because I don't like the idea of anything less than a good looking boat. I know I am meticulous, and capable of anything, but the install jobs I have seen posted over the last 9 years is anything but pretty, so I can't bring myself to do it. Plus, even in a 240, dumping that kind of weight on the transom is just going to change the ride dynamic and stability, not to mention economy and performance. I'm not knocking anyone for doing it, I get it, they produce a different sound and it can be irritating at cruise or WOT...even when idling along, they produce more sound than do the I/O counterparts. But they just aren't that bad and an I/O is loud too when at cruise or WOT, and most of that noise in all boats is wind at that point. I am in the camp of adding quality stereo sound to the interior to drown out the less desired noises. Again, not an expert or even experienced in sound reduction. But I like the 52mph my SX will run, and it cruises so cheap at 32mph that I can hardly raise a brow at the boat. The one thing I see the last year is that many new owners have come into the boats, with prior ski experience or reading Green Hulk or other ski based forums, and want to apply that to a boat that weights much more and just has totally different characteristics. I have no doubt that improvements can be made and I completely agree that answering that is best done at the manufacturing point. But the cost and reward equation aftermarket won't be solved by the ski world, nor do I think the equation will balance well overall. But again, I am reading and learning, as always!

 

[Bruce]

@txav8r, @swatski has added sound deadening and other upgrades to his boat and ended up with a quieter and faster boat than stock. Personally I applaud his experimentation and enjoy reading about the results.

 

[swatski]

Intake and exhaust are the two main areas for noise. I was thinking they may have changed the rubber between the coupler blades also but that is just a guess. I know we have several plastic baffle boxes on the exhaust systems that help reduce noise but I can't speculate just how much they help.
Sea doo had two mufflers and rubber wraps around them on the 4 stroke skies that I had years back, those made a difference.
Honestly I just don't see how the coupler would quiet things much. My feeling is if they had them available and someone tried them it would most likely end up being a big waste of a lot of time, effort and money with little or no difference in sound.
I would suggest looking at something like this for vibration reduction http://www.yanmarhelp.com/i_mounts.htm

Thank you for replies. I agree with @txav8r to a large extent, there are many many mods that do not translate well between skis and boats, same engines notwithstanding!
What made me think about couplers is the Yamaha statements about the “quiet ride” and also when I noticed a significant vibration and noise reduction when running with a plastic wear ring liner.
@Cobra Jet Steering LLC I like the mounts idea, but feel little quizzy about the "bounciness" at lower RPMs, as in the second schematic in the link site. Do you know if these mounts would work in our boats with our high reving engines? Any one you know with first hand experience in a jet or ski? I'm would be willing to try it.

 

[Cobra Jet Steering LLC]

Nope I just recalled people in the past talking about a quieter motor mount so I thought I would pass it along. I don't worry about the noise I actually removed my larger water box from one of my sea doo 4tec skies to make it louder and I put baseball cards in the pump to drag on the impeller for extra noise.

 

[Cobra Jet Steering LLC]

I believe your exhaust exit hose exits near the jet pump inside the pump recess area, if you look at a ski the area has some brackets and rubber blankets that enclose it so it captures the exhaust sound when it comes out of the pipe, it should be visible in this diagram http://www.yamahapartshouse.com/oemparts/a/yam/52781a32f87002271845c257/jet-unit-4 part number 35 and 36 with some brackets that attach them to the pump part number 2 in any event I don't believe your boat has this baffle and I am sure it is to reduce the noise where the exhaust exits the system so next time you see a ski with the 1800 engine pay attention to this, I think it may help some.

 

[swatski]

And just to be perfectly clear - my intention here is NOT to start another noise reduction thread... I am interested in vibration reduction technologies that could be applied to our boats. Whether of not they contribute to the noise factor, there is a lot of bad engine vibes resonating throughout the boat I would like to see gone.

Regarding the Vibratech patented technology, which I think is quite brilliant, here are some random quotes.

Here is a quote from a Group K write up (keep in mind - this is pretty dated):

“One new item we are recommending for our modified engines is a "Fluid Balancer" drive coupler that is fitted to the engine. Despite it’s somewhat small diameter, this balancer (that replaces the stock engine drive coupler) makes for a very significant reduction in overall engine vibration, as well as a noticeable increase in acceleration and peak rpm ability (we don’t know why it increases rpms…we just know it does). We consider the installation of this balancer to be "highly recommended", for no more than it’s ability to reduce wear and tear on all the hull and driveline components. The acceleration and rpm increases are just an added bonus. You can obtain this balancer directly from the manufacturer (Fluid Balancer (716) 937-7903 ext. 254).”

And one from Jims Performance on Grenhulk forum:

“Vibratech has been around quite awhile. They are engine harmonic dampners. Each time a piston fires, it creates a frequency that can wreak havoc on engines. These frequencies, when not controlled can actually cause a crankshaft to break in half. Controlling the frequencies helps controls crankshaft flex, and increases horsepower and durability.
Vibratech has a steel ring that floats in a viscous silicone type fluid, inside another steel ring that helps absorb vibration/harmonics. Really good stuff.. You could actually feel the engine running smoother at all rpms. “

 

[Bruce]

Do you know how expensive these Vibratech fluid balancers are?

 

[Cobra Jet Steering LLC]

I can tell you that I put 650 hours on my 1800 supercharged engine in a few years with no problems from vibration.

 

[swatski]

Do you know how expensive these Vibratech fluid balancers are?

Almost impossible to find... and expensive! Here is one sold in 2010:

Vibra Tech fluid balancer coupler and Riva Racing billet aluminum coupler $350 SOLD

 

[swatski]

I can tell you that I put 650 hours on my 1800 supercharged engine in a few years with no problems from vibration.

Thanks, that is good to know! I am not so much worried about the reliability issues with these engines, they seem ridiculously robust. It is more about my comfort!

 

[dan144k]

Several people use dynamat or knoknoise or other rubber foil based product to absorb vibration and vibration noise. The sounddown products also use this between the foam sound absorbing materials.
@swatski
1. I insulated the Waterboxs 80% with sounddown. Did not do the round ends.
2. then used the knoknoise under the swim deck to eliminate vibration noise. The v area.
3. Then cut up some foam wedge and pushed into rear corners of the boat.
4. Put knoknoise and sound down everywhere I could reach in exhaust and engine compartments

 

[swatski]

I have assumed (mistakenly) that polyurethane dampers / mounts would be more flexible, "softer", and more shock-absorbent as compared to hard rubber. But in reading, it is clearly not the case.

Turns out that, in jet skis, poly mounts are used purely for strength often at the expense of vibration. I guess it makes sense for jumping and slumming the waves...

Interestingly, here is a response from Robin Haas at Rhaas Products, a manufacturer of aftermarket engine mounts etc., to my inquiry about vibration absorbing engine mounts and coupler dampners:

"Thank you for your inquiry. We do not make any drive dampeners. We did in the past and did not have the best luck with them. We do make engine mounts. I cannot say whether the vibrations in a jet boat would be better or worse. The urethane material we use is extremely resistant to the environment in a Jetski hull. The downfall of the material is dampening. The stock mounts will most likely be better for dampening. Our mounts are made to last in a rough environment, the dampening is also pretty good.
Each choice has its advantages and disadvantages. We have never had any complaints about vibrations with our Yamaha 4 stroke mounts.
Let me know if you have any more questions.
Thanks
Robin"