Gas type and price

[SCSX190]

I would expect the superchargers to use higher octane across the board as well. The 192 using higher octane than the 190. The Mustang Eco will run on 87 but you lose like 50 HP.

 

[swatski]

So if the waverunner 1.8L supercharged engine outputs a supposed 210HP and the jet boat 1.8L supercharged engine is "de-tuned", its safe to assume it produces less than 210HP?

Probably somewhere between 180HP (naturally aspirated 1.8L engine) and 210HP (supercharged 1.8L waverunner engine).

That would mean that the difference between the natural and supercharged versions is less than 30HP? (only gaining 30HP from a supercharger is not a huge increase anyway).

Makes it hard to justify the increase in boat price for the supercharged version verse the natural version...especially when the HP gain is less than 30HP and most likely no more than 20HP.

The hp rating is for max hp. My feeling is that the timing at WOT between the two ECUs/tunes is very close therefore you won't see much, if any difference in top hp/RPM. The difference will mostly be in the acceleration.

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[AZDANSX230HO]

It's all in tuning and compression ratios that determines how much timing an supercharged engine will operate under without detonation with different octane levels of fuel. In my racing days, I had a street tune that would run on 91 octane and a race tune that would run on 101 octane, I was running 14 Lb's of boost on my street tune, and 21 Lb's of boost on my race tune. In addition to the amount of boost was how much timing it was running safely with those tunes. All of the tuning was done on a Dyno that measured air/fuel ratio's at the exhaust bung.

So you can have a 1.8L Supercharged Engine that runs on 91 Octane with X amount of Boost/Timing, or you can have that same engine either running the same amount of boost or less on 87 octane, but less timing in the tune to keep it safe.

 

[AZDANSX230HO]

All of which would reduce the HP, correct?

So it can't be both ways. You can't have a de-tuned engine running on less octane that will produce as much HP as another exact same engine that is tuned up and running higher octane.

The latter will produce more HP....

Correct.

 

[swatski]

So if that is true, then it convolutes the issue further. Most jet boats and waverunners are designed to run hard at WOT for extended periods of time...if the timing is the same at WOT, why does yamaha recommend 87 for boats and 91 for waverunners?

I don't know for sure. I played with the Maptuner and various ECU programs a lot. The palpable, large difference was in the midrange, not the top. It was the N/A 1.8, not SC, but it is supposed to be similar for both.
BTW - If you get any major top speed gains with ECU reflash, it comes primarily from the increase in RPM beyond what the stock rev limiter permits. The gains are much more substantial in SC as they gain boos with RPM increase.

"if the timing is the same at WOT, why does yamaha recommend 87 for boats and 91 for waverunners?"
Well, maybe because (with advanced timing) they would blow the engine in midrange?

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[swatski]

I dunno, sounds like a lot of speculation and guessing. The true answer is probably more straight forward or at least should be.

Either the boat 1.8L SC produces less HP or Yamaha is incorrect/made an error with it octane recommendation for either the waverunner or the jetboat.

I missed some of the posts as I was typing. Why does it have to be complicated?

The answer is (most likely) completely strait forward. The boat and the ski SC 1.8 produce the same max hp. The ski is tuned with advanced timing in the midrange for better acceleration. Which - BTW - is all that "closed course" racers care about, anyway. With advanced timing, you have to use premium octane to prevent detonation. These engines have no knock sensors, so you can ...uck them up very quickly if running hard.

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[swatski]

I would expect the superchargers to use higher octane across the board as well. The 192 using higher octane than the 190. The Mustang Eco will run on 87 but you lose like 50 HP.

That is actually not the case with those Yamaha 1.8 engines, N/A run substantially higher compression ratio vs SC.

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[swatski]

Like I said, still sounds like a lot of guessing and speculation...has anyone confirmed the boat 1.8l SC is timed differently? If its not then the whole idea/reasoning for why the different recommendations becomes moot.

Why would ECU be a different part if those ran the same programs?

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[AZDANSX230HO]

I just looked on Yamaha's website, the only jet skis they have with the 1.8L supercharged, Super Vortex High Output Marine engines are the FZR, FZS, FX SVHO, & FX CRUISER SVHO, they all require Premium Unleaded. The HP Specs I have found online (which are hard to find) show anywhere between 265 HP is 270 HP for 2016 SVHO Models. The Non-Supercharged models including High Output Models are Regular Unleaded.

 

[swatski]

Is that the case only for the ECU? Are the boat 1.8L SC engine part numbers (all other parts or majority of them) the exact same as the waverunner 1.8L SC engine part numbers?

I suspect the part numbers are different in most instances which would indicate that the ECU maybe the same

Many if not most engine parts are positively swap-able between boats and skis, even between SHOs and 1.8l N/As. I don't think the ECUs are.

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[AZDANSX230HO]

http://www.boattest.com/review/yamaha/3259_fzr-svho

Shows 270 HP.

 

[swatski]

That still doesn't answer the question, being able to interchange the parts doesn't prove the part numbers are the same. If all the part numbers are different, then basing the assumption that the ECUs are different because the part numbers are different doesn't hold water

You are correct.

 

[AZDANSX230HO]

Never saw that. Interesting. But it is not confirmed, only estimated. "1 x 270-hp Yamaha 1.8L SVHO (est. hp)"

It would be nice if they actually published the HP Numbers on the jet ski's so we can actually compare when it goes into a boat if the HP is less due to regular grade fuel with de-tuning the engines.

 

[AZDANSX230HO]

Boattest should just put the engine on a dyno. I saw a video where they did that with the 1.8L natural engine a couple of years ago. Not sure they disclosed the fuel they used however

I agree.

 

[SCSX190]

According to this article, Yamaha claims the 2016 FX SVHO has 250HP and uses Premium fuel. The normally aspirated 1.8L in the 190 is 177HP High Output(non-CARB, 166HP CARB) and the Supercharged 192 is 210HP Super High Output. HO != SHO != SVHO. The SVHO is a newly developed engine based on the SHO engine and therefore no the same.



http://www.wired.com/2016/03/meet-luxury-performance-sedan-jet-skis/

"The 2016 FX Cruiser SVHO is Yamaha’s top-of-the-line WaveRunner, and it’s a crazy balance of power and grandeur. According to Yamaha, its 250-horsepower, fuel-injected, four-cylinder engine gives it a top speed of 70mph."

"A full 18.5-gallon tank of premium unleaded gas can translate to more than 100 miles of water travel, just as long as you’re not gunning it the whole time."

 

[SCSX190]

I think it is safe to say that the SVHO provides upwards of 40hp increase over the SHO due to engine revisions and tuning. The HO vs. the SHO is only 33HP for non-CARB engines and 44 for CARB. In any event, this was a very informative discussion.

 

[Tobes]

The fact that the SVHO has a larger intercooler means it potentially can run more timing and/or boost which would mean the need for premium fuel. I would bet with the SVHO intercooler, 91+, and a tune, you would gain a bit more than you think. Youd be able to add quite a bit of timing due to cooler charge and less detonation.

 

[SCSX190]

Filling up my boat with regular pump gas and look what pulls up, Godzilla
...

 

[AZDANSX230HO]

Filling up my boat with regular pump gas and look what pulls up, Godzilla
...
View attachment 44178

GTR's are some badass cars, a bit expensive though!!