Sound dampening for engine compartment

[cwfehr]

I saw one older post on sound dampening and was wondering if anybody has tried one form of sound insulation in their engine compartment on a later model year Moomba? If yes, how did it work? What product did you use? Was it worth it in the end? For reference I have 19 Moomba Max and we are between 3700 and 4000 rpm at surf speeds which means there is substantial engine noise.

Sent from my SM-G973W using Tapatalk

[RC_Hinojosa]

I have a '17 Craz....I was on planning on using Dynamat but it's kinda pricey. Killmat had excellent reviews and way more affordable.

I lined underneath the helm first, my XXX sub opened up some rattles [emoji344][emoji344][emoji344]

I also lined the underside of my engine storage tray and the backside of the v-drive hump.

IMO the sound deadening plus my surf pipe made a noticeable difference in attenuation of engine noise.



Sent from my Note 9 using Tapatalk

[cwfehr]

Good to know about killmat. I hadn't considered a surf pipe either. I always thought the noise was primarily from the engine compartment. Thank you! What surf pipe did you use?

Sent from my SM-G973W using Tapatalk

[RC_Hinojosa]

I have the OEM surfpipe.

It wasn't an option in '17 so I've heard the Raptor motor with and without it.

IMHO it's one of the best stereo upgrades for it's price and I think most of the kinks have been worked out by now.

The first few years of parts had issues with weld cracks and broken bolts but that's also why I went OEM vs FAE so I wouldn't have warranty hassles.

https://uploads.tapatalk-cdn.com/20210131/8f044c4e945c5ad4023a911f6a254f8e.jpghttps://uploads.tapatalk-cdn.com/20210131/7f6ad4ae3e61c0ec938be5e3088930ea.jpg

Sent from my Note 9 using Tapatalk

[2in2out]

I have a '17 Craz....I was on planning on using Dynamat but it's kinda pricey. Killmat had excellent reviews and way more affordable.

I lined underneath the helm first, my XXX sub opened up some rattles [emoji344][emoji344][emoji344]

I also lined the underside of my engine storage tray and the backside of the v-drive hump.

IMO the sound deadening plus my surf pipe made a noticeable difference in attenuation of engine noise.



Sent from my Note 9 using Tapatalk


RC, did you have to use a heat gun to apply, and how was the adhesion? Reading some of the reviews it sounds like many buyers were unimpressed with the adhesion.

I’m considering adding some to the transmission cover on my SA, as it produces quite a bit of sound at idle.

Have any Supra owners added sound insulation? Where did you put it and did it have an appreciable effect?

[KnoxMojo]

I saw one older post on sound dampening and was wondering if anybody has tried one form of sound insulation in their engine compartment on a later model year Moomba? If yes, how did it work? What product did you use? Was it worth it in the end? For reference I have 19 Moomba Max and we are between 3700 and 4000 rpm at surf speeds which means there is substantial engine noise.

Sent from my SM-G973W using Tapatalk

I have used the cheap amazon peel and stick sound matt on my last 2 boats. I lined the engine divider panels, the firewall behind the rear seats and all the transmission area. A lot of what you hear is transmission whine, the matt alleviated a lot of that. And combined with surf pipe, it is now fairly quite.

[RC_Hinojosa]

RC, did you have to use a heat gun to apply, and how was the adhesion? Reading some of the reviews it sounds like many buyers were unimpressed with the adhesion.

I’m considering adding some to the transmission cover on my SA, as it produces quite a bit of sound at idle.

Have any Supra owners added sound insulation? Where did you put it and did it have an appreciable effect?

I did not need a heat gun to apply. Adhesion is like tar paper (at least in TX)....it ain't going anywhere.


Sent from my Note 9 using Tapatalk

[cwfehr]

Great info. Ty

Sent from my SM-G973W using Tapatalk

[parrothd]

Great info. Ty

Sent from my SM-G973W using Tapatalk

I dynomated the front engine wall with mats and foam, it helps a little but probably not worth the effort. The raptor is freaking loud.

[KnoxMojo]

I dynomated the front engine wall with mats and foam, it helps a little but probably not worth the effort. The raptor is freaking loud.

Use the matt on the transmission tunnel, that will help a lot.

[rhouse181]

Added double layers of Noico 80 mil butyl and aluminized heat shield to the trans and engine covers on my Kaiyen:

https://i.imgur.com/urZdrkG.jpg

https://i.imgur.com/VukvUpS.jpg

Noico is way less expensive than dynamat. Just make sure you get one of those metal rollers to correctly adhere the self adhesive matts to the panel.

[cwfehr]

Did the Noico help a lot? Anybody do any decibel testing?

Sent from my SM-G973W using Tapatalk

[parrothd]

Use the matt on the transmission tunnel, that will help a lot.

Already have it, don't forget to cover the plastic door.

[KnoxMojo]

Already have it, don't forget to cover the plastic door.

I did it everywhere, removed that whole section of flooring in my SA to do it.

[KnoxMojo]

Did the Noico help a lot? Anybody do any decibel testing?

Sent from my SM-G973W using Tapatalk

I don't have a meter. But before at 22 mph, you had to about yell at people sitting around you, now you can talk mostly normal. Don't need a meter to know it made a difference.


And never thought about doing a double layer. Guess I have another project! Lol

[cwfehr]

Thanks for all the help. Ordered some sound dampening material from amazon. Noico 150 mil, 4mm thick. It was cheap so will give it a go. Also ordered the OEM surf pipe. Hopefully, between the two projects the noise is reduced enough that I don't feel the need to upgrade the sound system!https://uploads.tapatalk-cdn.com/20210203/618145893754f4e6326820e4c923f737.jpg

Sent from my SM-G973W using Tapatalk

[RC_Hinojosa]

That's not the same kinda stuff. You may have a harder time getting that to conform to non flat surfaces as that uses a different adhesive.

https://uploads.tapatalk-cdn.com/20210203/f5431983bec2bc473f14f90684c7b93e.jpg

Sent from my Note 9 using Tapatalk

[Holdmybeer]

I'm with RC & Rhouse.
I put myself through college doing auto electronic upgrades. Best sound systems were always "matted" to stop the metal popping noises and hear the music. Fast forward to today and working in car manufacturing we apply a liquid sound deadener that cures like dymamat or other brands. Night and day difference.

I have kilamat in my amazon cart right now but waiting since it is 20* in Ohio. My plan was the firewall, interior engine side panels, Trans cover, fuel tank cover (floor), and back of the sub panel under the dash. Next will be the surf pipe and hoping we can finally talk while pulling someone. Every boat I have had has been an I/O and you have to yell regardless of what you are doing.

[996scott]

on our new Craz the whine from the transmission is VERY noticeable, I don't like it at all. I don't think it is the exhaust or the engine, but the transmission,v-drive. I bought a box of Killmat and am just getting started with the v-drive cover. It's very easy to install and sticks well. I will see if it helps in the spring. Fingers crossed.

[cwfehr]

That's not the same kinda stuff. You may have a harder time getting that to conform to non flat surfaces as that uses a different adhesive.

https://uploads.tapatalk-cdn.com/20210203/f5431983bec2bc473f14f90684c7b93e.jpg

Sent from my Note 9 using TapatalkYou may be right. Not as plyable but am hoping it will adhere to the larger surfaces. I may have to get some of the 80mil as well. Let you know in a few months when we thaw out.

Sent from my SM-G973W using Tapatalk

[sandm]

on our new Craz the whine from the transmission is VERY noticeable, I don't like it at all. I don't think it is the exhaust or the engine, but the transmission,v-drive. I bought a box of Killmat and am just getting started with the v-drive cover. It's very easy to install and sticks well. I will see if it helps in the spring. Fingers crossed.

I'm with ya and think it's these indmar running gear they are sourcing. they are stupid loud when compared to the old pcm's I have had in the past.
we're toying around with doing the same thing.

[rhouse181]

Thanks for all the help. Ordered some sound dampening material from amazon. Noico 150 mil, 4mm thick. It was cheap so will give it a go. Also ordered the OEM surf pipe. Hopefully, between the two projects the noise is reduced enough that I don't feel the need to upgrade the sound system!https://uploads.tapatalk-cdn.com/20210203/618145893754f4e6326820e4c923f737.jpg

Sent from my SM-G973W using Tapatalk

That low density foam won’t be as heat resistant as the butyl and there isn’t an aluminum thermal “reflective” layer... don’t know if the running gear throws enough radiant heat to make a difference for the engine and trans covers.

Would definitely steer clear of the manifold areas though if you were planning on hitting the rear locker dividers...

[cwfehr]

Agreed. Ordered the 80mil just a few minutes ago for the hotter areas. Also, if the thicker stuff is too difficult to install I have another option.

Sent from my SM-G973W using Tapatalk

[rhouse181]

on our new Craz the whine from the transmission is VERY noticeable, I don't like it at all. I don't think it is the exhaust or the engine, but the transmission,v-drive. I bought a box of Killmat and am just getting started with the v-drive cover. It's very easy to install and sticks well. I will see if it helps in the spring. Fingers crossed.

V drive quiets down considerably after the 20 hr oil / alignment service... or maybe I just got used to it more.

[MJHSupra]

Added double layers of Noico 80 mil butyl and aluminized heat shield to the trans and engine covers on my Kaiyen:

Noico is way less expensive than dynamat. Just make sure you get one of those metal rollers to correctly adhere the self adhesive matts to the panel.

Boxes are either 18 sqft or 36 sqft. How much do you need to double?

Sent from my P00I using Tapatalk

[rhouse181]

Boxes are either 18 sqft or 36 sqft. How much do you need to double?

Sent from my P00I using Tapatalk

Went through the 18 sq ft box on just the engine and trans covers.

[parrothd]

I'm with ya and think it's these indmar running gear they are sourcing. they are stupid loud when compared to the old pcm's I have had in the past.
we're toying around with doing the same thing.

I think the noise on the raptor motor is from the exhuast that is now facing forward and right behind the back seat. You have the all exhaust piping, cats and exhaust noise directed toward you. The older assault engines had the exhuast facing the rear. My lsv with a surf pipe was so quite you could hear the water rippling.

[Buckeye]

Hi All,
I am a new member and just bought a ‘21 Craz.. There is a high pitch whine that gets loader the more I accelerate. It’s very annoying. It sounds like it is coming from the V-drive. Rep. At the dealer said it was normal, but I’m not so sure. Everyone that gets in the boat comments on it. Am having them take another look when I take it in for the 10 hr. Check up. I had a ‘91 Barefoot Nautique prior that was a v-drive there was no noticeable noise from the v-drive. I guess I thought a new boat would be much quieter. Thoughts?

[Holdmybeer]

My 15 Mojo has a v-drive whine.
My buddy's 19 Craz has a v-drive whine.

I insulated the dog house and engine side panels and it is much quieter than his craz.

Your barefoot nautique was a direct drive and I'm sure was quieter.

[996scott]

pretty normal, unfortunately. I have a 21 Craz and it has the same whine. Was annoying at first but i used a lot of sound deadening and it has helped a little. Not a ton but a little. We usually have the music on so we don't notice it a lot.

[HFarr]

I added some 3/8" sound foam to my 2021 Makai, it whined loudly too, and it helped a lot, but you can still hear it. I will do floor panel and maybe engine side panels next. Just with what I did on the trans cover, now when new people get in the boat they don't immediately ask me what that high pitch squeal is. I also put a 1" wide strip around the back wall of the boat right below where the trans cover touches it. This closed off the gap that is there, and you can't see the foam. I didn't take a picture if that, but will when I take up the floor to do it too. https://uploads.tapatalk-cdn.com/20210523/9590b2a0c3d189809d44ef0b1fdff8a5.jpghttps://uploads.tapatalk-cdn.com/20210523/38e214ff56846e191f807e9a43fb0f30.jpghttps://uploads.tapatalk-cdn.com/20210523/45924ba5fb4eff4b1e3f61688ae8a246.jpg

Sent from my moto z4 using Tapatalk

[SONIC]

The raptor motors and vdrives all have a high pitched annoying whine.
It's because they use atf in the vdrives rather than true gear oil for whatever reason.
Walter used to do the same and then sent out a tsb to swap to engine oil and they got instantly quiet. I'm hoping indmar follows suit at some point.

That being said I coated the underside of the transmission bump in noice 80 and it made a big difference.
I pulled the floor and partially coated it as well (ran out, need to pull it again and finish it) and it made a big difference.
Between the two I don't really mind the whine anymore. Had another boater the other day amazed that my boat was even running said he couldn't hear it at all from his boat while my wife was idling around at the dock.

[rdlangston13]

The raptor motors and vdrives all have a high pitched annoying whine.
It's because they use atf in the vdrives rather than true gear oil for whatever reason.
Walter used to do the same and then sent out a tsb to swap to engine oil and they got instantly quiet. I'm hoping indmar follows suit at some point.

That being said I coated the underside of the transmission bump in noice 80 and it made a big difference.
I pulled the floor and partially coated it as well (ran out, need to pull it again and finish it) and it made a big difference.
Between the two I don't really mind the whine anymore. Had another boater the other day amazed that my boat was even running said he couldn't hear it at all from his boat while my wife was idling around at the dock.

My 17 with the raptor does not use ATF in the v-drive. ATF is for the transmisson and 50 weight synthetic oil in the v-drive if i recall.

[SONIC]

I stand corrected there, I'll have to go back through some older posts and see what I was confusing it with now!

[Buckeye]

https://youtu.be/_n-RBKhkEoc

Thank you all for the help. I had my son upload these for me. Hopefully this works.
Any advice as to which sound deadening material is best? HFarr, yours looks great. What did you use?

[HFarr]

https://youtu.be/_n-RBKhkEoc

Thank you all for the help. I had my son upload these for me. Hopefully this works.
Any advice as to which sound deadening material is best? HFarr, yours looks great. What did you use?I got this off Amazon. It was pretty easy to cut with scissors, and was peel and stick.

2971429714

Sent from my moto z4 using Tapatalk

[HFarr]

I also made some cardboard templates. Here is what they measured. I just flipped the angle one for the two side pieces. Sorry for the crude writing. I later went back and filled in the edges of the cover with scrap too. It does not sit flat on the boat, so leaving it bare creates a gap for sound at the floor where it screws down too. https://uploads.tapatalk-cdn.com/20210523/ff70264384c020bf78bd86cafe48e088.jpghttps://uploads.tapatalk-cdn.com/20210523/2c69159a5156774bda0cddb953ad5d2b.jpghttps://uploads.tapatalk-cdn.com/20210523/15623be5bd3671a020be2438a0a79fee.jpghttps://uploads.tapatalk-cdn.com/20210523/e8ecbabcd47c5f4b0126958edc1a8493.jpg

Sent from my moto z4 using Tapatalk

[HFarr]

Sorry. That Amazon pic was crappy. Here it is again
https://uploads.tapatalk-cdn.com/20210523/886c201a6b91c57ef44c1ba3988540d8.jpg

Sent from my moto z4 using Tapatalk

[HFarr]

Ok. Let's try againhttps://uploads.tapatalk-cdn.com/20210523/2baaaf630197b0e510854b72b4dd2d03.jpg

Sent from my moto z4 using Tapatalk

[Buckeye]

Thank you. So, that is what yours sounded like prior to sound deadening?

[HFarr]

Yes. It was super loud. My wife and I even mentioned it to the salesman on our test ride. He said same thing everyone else has said. " Oh, thats just what the vdrive sounds like". At that time I was already thinking about noise padding.


Sent from my moto z4 using Tapatalk

[HFarr]

This is the Makai after just insulating the transmission cover only. The whine is mostly there under acceleration, but seems to disappear after you level off. And it's not as loud as it was. I jumped it up to about 30 mph and down to 20 in the video. I will do the floor panel next since it is wide open to the v-drive too. I can see where it would probably help too when I had the trans cover off.

https://youtu.be/apu62irxEKA

Sent from my moto z4 using Tapatalk

[Buckeye]

Yep. I had the exact same experience and the sales rep. Said it was normal. I find it surprising that that is the norm. If customers heard that on a test drive prior to purchase, I think it would definitely impact sales. I may have looked at other options. I still love my boat, but need to address that whiney noise or listen to my wife whine about it!
I agree that it makes sense to do the floor panel as well. Thanks HFarr

[larry_arizona]

Curious how much of this noise might be prop singing.

My 16x13.9 sings at 1575rpms


Sent from my iPhone using Tapatalk

[HFarr]

I guess it could be, but it seems so many people have it with so many different prop pitches, and the other boats with different brand drives dont seem to do it. Direct drives don't seem to do it either. Somewhere in all these post's it was mentioned that the type of gears ( tooth shape) were changed and that's when it all began.

Sent from my moto z4 using Tapatalk

[Buckeye]

Maybe, although I would not know what prop sing sounds like. I did read about it on another post and I plan to have the dealer check for “prop sing” when I take it in for its post breaking period checkup. I will let you know if they come up with anything. I did open the door access panel to the v-drive and it definitely sounds like it is coming from that area. I wonder if prop sing carries up the shaft and presents in the v-drive area?