Has anyone plotted this curve yet?

[McMark]

1.8L NA vs SC fuel consumption vs speed. I’m curious if there is a cruising speed where the NA and the SC are close in fuel burn.

28 mph was a good cruising speed for my AR240 as far as fuel burn, 10-12 gph. Wondering the fuel burn for the supercharged engines at ~28 mph.

Thanks!
Mark

 

[HangOutdoors]

following.

 

[gallobg]

Boat Test usually has these curves. You could compare their results. Note these are 2019 vs 2018, so not apples to apples due to the model year changes (new hull, etc).

2019 AR195

Yamaha AR195 (2019-) | BoatTEST

Yamaha’s AR195 is an entry-level jet driven runabout designed for families to have fun on the water while providing them with everything they need to do just that – without needing a long list of options. Everything needed is standard.

boattest.com

2018 AR190

Yamaha AR190 (2019-) | BoatTEST

Yamaha’s AR190 is a jet driven thrill ride that was designed solely around getting families on the water, providing them with everything they need, and ensuring they remain safe.

boattest.com

From these charts it looks to be about 6.5 gph vs 10.5 gph at 28mph. I don't really see a common point on the curves, the SC engine seems to burn more at all speeds.

 

[McMark]

Yea. Looks like 38% more fuel at cruise just for running super chargers. That helps. I wish that were closer.

 

[biglar155]

Yea. Looks like 38% more fuel at cruise just for running super chargers. That helps. I wish that were closer.

500 Horsepower!



"C'mon Max.... You've seen it.... You've HEARD it....... and you're still asking questions?"

 

[gallobg]

I don’t have any experience with the 190 series boats. The 2019 AR195 is my first jet boat experience. Having said that, for my use with inland lakes and water sports, I would not be happy with the performance of a 190 engine. There are times when I feel the 195 engine is almost not enough - like launching a surfer with 800lbs on the rear deck.

 

[McMark]

I’m just trying to put together some numbers on the big FSH with NA vs SC is all. I was very happy with the performance of my AR240 but if the SC version was closer in fuel consumption why not have that extra oomph in your back pocket!

 

[Enduro900]

I was hoping for the same thing.....if it close at cruising speeds......bummed if its that much higher even cruising.....

 

[mrcleanr6]

i think for those #'s to be fair you would need to test the same boat in the same conditions. as stated thats not an apples to apples comparison. being the same motor only supercharged i bet those #'s are alot closer in reality. it might not be at the same rpm since the cams are different but if you found the rpm where both engines ran most efficiently, not boat speed, i bet it would be way closer. my fzs with the svho for instance, stock it got decent range at cruise rpm. now i have done engine work to it, bigger injectors, higher boost etc. now is seems like its a gas hog and will suck an 18gal tank dry in 45min BUT thats only because i am tapping that extra power. if i still stay at cruise rpm then its actually the same as it was stock even though the injectors are bigger. i guess its easiest to say fuel= power so if your tapping into the power equally on both na and svho engines then the consumption should only be slightly more on the svho because the only extra work the engine has to do over the na model is spin the supercharger.

 

[2kwik4u]

I'll be happy to develop a curve for a 190 if anyone wants it. Just need about 10-12 data points to fit a curve to. Anyone with a 195 want to join along?

 

[gallobg]

I’m just trying to put together some numbers on the big FSH with NA vs SC is all. I was very happy with the performance of my AR240 but if the SC version was closer in fuel consumption why not have that extra oomph in your back pocket!

If you're talking about the new 25' FSH, then the best we can do is extrapolate. But in virtually every scenario I have seen, the SC engines suck down way more gas than the normal engines. Just look at the fuel burn numbers for the 27' boats last year. 40.8 gph at wide open!

Yamaha 275SD (2019-) | BoatTEST

boattest.com

 

[McMark]

My back of the napkin for the SC FSH at 5500 came in at 17.3 gph. Just a touch better than the 27 footer that you posted. So essentially 38% more fuel at cruise. I’ll stick with the NA. Man, I was hoping for closer though! I don’t need a race car, I need range.

 

[Wishfull1]

I just happened to take a picture yesterday while comparing speedo vs tablet GPS. 29.6 mph, 5900 ish rpm and 10.6 gph. 5 adults onboard the '18 SX195.

 

[ripler]

@McMark Off subject but a lot of new Yamahas on the Mon this year, I used to be the only one for a long time.

 

[McMark]

Hey @ripler !!! I saw you the other day (Last Saturday evening I think) but I’m sure you didn’t recognize me. At the moment we have an old Boston Whaler 17’. There does seem to be more and more Yamahas. Give me a wave if you see us.

 

[ripler]

Hey @ripler !!! I saw you the other day (Last Saturday evening I think) but I’m sure you didn’t recognize me. At the moment we have an old Boston Whaler 17’. There does seem to be more and more Yamahas. Give me a wave if you see us.

View attachment 130228

Will do, I like Boston Whalers, I did a lot of work at their plant at a previous job, I engineered the machine that injected foam in the hull.

 

[Neutron]

500 Horsepower!

View attachment 130179

"C'mon Max.... You've seen it.... You've HEARD it....... and you're still asking questions?"

Favorite movie car EVER!!!!!

 

[Canuckjetboater]

1.8L NA vs SC fuel consumption vs speed. I’m curious if there is a cruising speed where the NA and the SC are close in fuel burn.

28 mph was a good cruising speed for my AR240 as far as fuel burn, 10-12 gph. Wondering the fuel burn for the supercharged engines at ~28 mph.

Thanks!
Mark

@McMark ....that would be interesting to see. I believe boating magazines have posted a number of fuel burn stats for SVHO (SC 1.8s). If there are stats for "standard" 1.8s - and there should be that would be an interesting comparison. Of course, regarding fuel, bif you have to ask how much X burns........

 

[FSH 210 Sport]

Read through the posts here and thought I’d comment regarding the fuel burn of the SC engines. I made a similar post yesterday in another thread.

SC engines boost is rpm specific since the SC is engine driven, and centrifugal type SC’s are most efficient at rated rpm. Therefore the fuel delivery is for lack of a better way of putting it, linear in regards to rpm. So you are not going to see fuel burn numbers that are close to the NA version of the engine.

However, if the SVHO motor was turbocharged that would be a different story as a turbocharged engines boost is directly proportional to the amount of fuel being burned and engine speed, and a turbo has no parasitic losses like a SC does which is usually 7-10%. So very rough math, if the output of the 1.8L SC engine is 250 net, gross hp is around 280 if the SC takes 10% to turn it, or there abouts. Restated, at any given rpm the SC engine is producing 10% more power than is being used to just drive the pump.

The big advantage a SC has over a turbo is instant boost / power, while a turbo takes a bit to spool up, and they’re small, and simple to install. The big advantage a turbo has is that it will produce the same peak power at high altitude where as the SC engine will experience roughly 1.5% hp loss Per 1000’ of elevation gain. NA engines lose a minimum of 3% hp per 1000’ of elevation gain, usually more.

There are also hybrid engines that use a SC and turbochargers. With that set up you get the instant boost of the SC, and when the turbos spool up the boost is coming from the turbos and the parasitic losses of the SC go away since there is no longer a pressure differential across the SC. First time I saw that was in the crew boats I used to take to the off shore oil rigs... twin Detroit diesels that were supercharged with twin turbochargers. These boats were 60-70 feet long and had been repurposed from the oil fields in the bayou’s to the ocean. The Capt told me in their original set up they would cruise at 50 Knots. They had been re-propped to only do 25 knots, even with 50 guys on that boat the capt had to be careful how hard he accelerated... pretty awesome... sorry for the segue, good memories.

Here is boat test & boating magazines fuel burn test data on the 2021 255 SD (1.8L NA) top, and the 2021 255 FSH Sport E (1.8L SC) Bottom.

 

[Neutron]

Read through the posts here and thought I’d comment regarding the fuel burn of the SC engines. I made a similar post yesterday in another thread.

SC engines boost is rpm specific since the SC is engine driven, and centrifugal type SC’s are most efficient at rated rpm. Therefore the fuel delivery is for lack of a better way of putting it, linear in regards to rpm. So you are not going to see fuel burn numbers that are close to the NA version of the engine.

However, if the SVHO motor was turbocharged that would be a different story as a turbocharged engines boost is directly proportional to the amount of fuel being burned and engine speed, and a turbo has no parasitic losses like a SC does which is usually 7-10%. So very rough math, if the output of the 1.8L SC engine is 250 net, gross hp is around 280 if the SC takes 10% to turn it, or there abouts. Restated, at any given rpm the SC engine is producing 10% more power than is being used to just drive the pump.

The big advantage a SC has over a turbo is instant boost / power, while a turbo takes a bit to spool up, and they’re small, and simple to install. The big advantage a turbo has is that it will produce the same peak power at high altitude where as the SC engine will experience roughly 1.5% hp loss Per 1000’ of elevation gain. NA engines lose a minimum of 3% hp per 1000’ of elevation gain, usually more.

There are also hybrid engines that use a SC and turbochargers. With that set up you get the instant boost of the SC, and when the turbos spool up the boost is coming from the turbos and the parasitic losses of the SC go away since there is no longer a pressure differential across the SC. First time I saw that was in the crew boats I used to take to the off shore oil rigs... twin Detroit diesels that were supercharged with twin turbochargers. These boats were 60-70 feet long and had been repurposed from the oil fields in the bayou’s to the ocean. The Capt told me in their original set up they would cruise at 50 Knots. They had been re-propped to only do 25 knots, even with 50 guys on that boat the capt had to be careful how hard he accelerated... pretty awesome... sorry for the segue, good memories.

Here is boat test & boating magazines fuel burn test data on the 2021 255 SD (1.8L NA) top, and the 2021 255 FSH Sport E (1.8L SC) Bottom.

View attachment 142112



View attachment 142111

As to your boat test charts. A 255sd and a 255 fsh use sc engines the last number 5 instead of a 2 designates that.

Edit,,,, saw the chart said 252 your test said 255 sorry