190 vs 195 noise levels?

[Rick Russler]

I was looking at another site that did separate boat tests of the 195 and the 190, and in the performance data tables they give decibel levels and rpms for different speeds. It shows significantly lower noise levels (and lower rpms) on the 195 vs the 190. Does this this seem right? Possibly a more powerful engine running at lower rpms to achieve the same speed, and a slightly larger pump, resulting in lower noise levels?

 

[viper15]

Were they comparing the same model year of 190 vs 195? I can’t see why one would be quieter than the other. But I think Yamaha improved the sound materials over a few model years.

 

[Rick Russler]

Yes. Both were reported to be 2018 models, but not tested side by side.

 

[Midnight2V]

The 195 is supercharged and high compression, there by making significantly more power at virtually all engine speeds. It also has a far more aggressive impeller and a 160mm pump vs 155 in the 190. This gives it the potential to generate more thrust for any given engine speed, and thereby higher vessel speed per RPM.

What all this means is that for any given vessel speed, the 195 is using less RPM than the 190. Engine RPM is the overwhelmingly decisive component of the noise levels these engines produce. So for virtually any given vessel speed, the 195 will make considerably less noise.

 

[swatski]

They always post decibel levels for various RPMs, so that is not an issue.

195 and 192s run significantly lower compression ratios as compared to N/A 1.8 engine boats. That could make them a little less noisy but I doubt it makes an audible difference.

The reason 195s are more quiet is most likely the fitting of the interior which is far nicer, with a lot more surface being covered/carpeted etc., and the additional soundproofing. That is one area where Yamaha has been making progress.

For example, the new 2015+ 240 hulls have the entire stern area divided up into compartments, some filled with soundproofing materials, makes a huge difference in noise reduction.

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[haknslash]

Ever since the cockpit interior update of the 2015's, the 190 and 192/195 interiors have remained very similar. Aside from the bow filler cushion, the only additional padding I'm aware of that you get on a 192 or 195 over a 190 is the center rear-facing bow backrest. Everything else is the same I believe (aside from colors/materials). You may be thinking of the older 2014 boats where the engine seat didn't have a full seat back cushion but rather just an upper back rest. I've had people comment my 192 was more quiet than their older 192 but I don't know if that would be the case today since I've removed the ribbon delete and that did add some throatier noise.

2014 style. Notice the fiberglass below the backrest.


2o15+ 190, 192 and 195 have a full back cushion over the engine hatch.


2o15+ 192 and 195's have the center rear-facing bow backrest. I'm not sure if this would actually muffle any of the noise of these boats since most of it seems to resonate from the engine hatch and rear storage compartments.


As for why the supercharged boats may seem quieter who knows. I know the Indmar supercharged 575 Roush Raptor engines are much quieter than the Raptor 400 or 440 engines. I'm guessing it turns lower RPM's. It is noticeably more quiet. Regardless of what that report said, all of these boats are going to be noisy. Some people go to great lengths to try and make them more quiet but I think it's near a lost cause. I just try and keep a ton of stuff in my rear storage compartments to help minimize some of the drone as it resonates through the boat. They are not overly obnoxious loud, just high revving engines you hear as if you were riding a jet ski.

 

[Rick Russler]

Does the supercharger give a high frequency whine that gives a “perception” of more noise? Or is that not significant.

 

[haknslash]

No you can't really hear it

 

[Matts18]

There are a few test reviews out there that comment on the quietness of the 195. In addition to what has been said, I believe it has a different engine coupling than the other 19 footers that is supposed to be quieter. Here is a quote from a boattest review on the 195: “Soundproofing made a noticeable difference that went from the screaming levels of the previous models to a more comfortable level that remained low enough where we were actually able to have a conversation while at cruise speed… a conversation about how quiet the boat was.”

 

[Midnight2V]

They always post decibel levels for various RPMs, so that is not an issue.

195 and 192s run significantly lower compression ratios as compared to N/A 1.8 engine boats. That could make them a little less noisy but I doubt it makes an audible difference.

The reason 195s are more quiet is most likely the fitting of the interior which is far nicer, with a lot more surface being covered/carpeted etc., and the additional soundproofing. That is one area where Yamaha has been making progress.

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The original SHO motor is 8.6:1, which is low pressure for a centrifugal SC. I had originally read and been told the SVHO is 9.5:1 with significantly stronger stock pistons, which is a considerable step up, and I would consider this to be a fairly high compression ratio for a supercharged engine. However, now I am finding more information saying that the SVHO is also 8.6:1 but with pistons that are stronger than those in the SHO. So now I'm not so sure. The 1.8l is 11.0:1 which is fairly high for a NA engine, and certainly much higher than the supercharged models, regardless of them being 8.6 or 9.5. But I agree, that the CR shouldn't make any real difference in noise levels.

Speaking of noise...Supercharger whine is typical of positive displacement, belt driven superchargers like roots or twin screw units. The acoustic frequency of the whine climbs with Engine RPM but doesn't tend to get louder once you reach full boost. Belt driven Centrifugal units are typically much quieter under load and tend to whistle at idle. This being my first experience with direct coupled centrifugal superchargers, all I can tell you is that I can't hear any evidence of a supercharger at all. I've been working on and around supercharged and turbo charged automobiles for 25 years and in most cases they do not add to raw decibel level of the engine. Superchargers may stand out at a few frequencies, but overall loudness is not something they tend to affect. Noise generation is mostly due to RPM, although as previously pointed out, noise suppression technology can significantly reduce it as well.