2023 FX SVHO stage 1+ [tune RPM Limiter and impeller selection)

[Mr. GP1800]

Is there any benefit to installing a 13/18 impeller to a 22 GP svho without a tune? current set up - cold air intake, fizzle BOV and ribbon delete. I do plan to do a stage 1 tune eventually.

Im guessing you’ll be on the rev limiter with a 13/18 on a stock tune. 13/20 would probably be ok

[Ski u l8tr]

Is there any benefit to installing a 13/18 impeller to a 22 GP svho without a tune? current set up - cold air intake, fizzle BOV and ribbon delete. I do plan to do a stage 1 tune eventually.

Did you notice any performance gains from the mods you have completed on stock tune?

[Mr. GP1800]

Did you notice any performance gains from the mods you have completed on stock tune?

You wont get any top speed gains until you flash the ECU. There can be performance improvements that don’t include top speed without flashing. Better hookup or slightly better acceleration, as well as better handling can be had without a reflash. The ECU reflash is the key to unlocking performance on these supercharged machines

[Ski u l8tr]

You wont get any top speed gains until you flash the ECU. There can be performance improvements that don't include top speed without flashing. Better hookup or slightly better acceleration, as well as better handling can be had without a reflash. The ECU reflash is the key to unlocking performance on these supercharged machines

Thanks. I was more wondering whether there was a noticeable difference in how the ski accelerated with having better breathing. I know top speed would be unaffected...

[K447]

- better breathing. ...

These engines are partially open loop, there is no sensor in the exhaust to inform the ECU about air:fuel ratio or EGT.

The factory tunes do have latitude and there is an intake manifold MAP sensor, but overall simply supplying 'better breathing' shifts the engine towards lean combustion.

One of the things that determines what Stage of tune should be used is the alterations to the engine environment. You select the tune that matches the actual engine mechanical and air flow modifications.

Riva tunes for Yamaha are matched to air flow.
Stage 1 tune is for totally unchanged SVHO engine with zero air intake alterations

Stage 1 Plus tune matches minor air intake changes, IUMK and aftermarket 'cold air' intake

Stage 2 tune expects the above plus an aftermarket intercooler

The selected tune alters the ECU fuel map to properly match the air flow conditions created by the mechanical changes to the engine.

Some changes, such as the ribbon delete and IMUK kit change the air flow balance across the cylinders. The tunes compensate for this by providing (just enough) more fuel to the individual cylinders that receive more air flow.

The tunes also adjust the ignition timing and overall fuel mapping along with RPM limiter increases, which is why even the Stage 1 tune with no hardware changes at all can deliver more power and speed.

[K447]

Hi. I have a 2022 fx svho with quite a few engine bolt ons, 13/18 prop, retainers, riva sponsons, plate and intake and 8800 agr tune. Ski has maxed out at 82.9 mph with a third of a tank on fresh water at sea level. Sustained 80mph with half a tank in salt water. I was a little surprised how many mods were required to get it cranking though so I would be keen to hear how it goes for you. Rpm sits around 8500/8600 at WOT

Just realized you have already gone through the upgrade process.

I shall leave my prior reply in place as information for others who may read this thread later.

[Ski u l8tr]

Just realized you have already gone through the upgrade process. I shall leave my prior reply in place as information for others who may read this thread later.

All good. It was an interesting process however the ski seems reasonably well dialled now....I did install the supercharger shaft upgrade kit just in case I want to progress things further in future....The 22 definitely felt slower than 21 stock but overall is far superior ski in terms of ride and handling. With the added mods it now seems to be the best of both worlds

[jetskr]

I did. Though i didnt gps it i did notice better low end and mid range. It def seemed to wake it up. I can only imagine what a tune will do. At this point im just trying to make it run as effieciently as possible and reliable too. And of course being on a budget trying to do one thing at a time as the money will allow

[teniie3]

That's fascinating. Maybe there wouldn't be a problem with giving it over for 8000 if that were genuinely the case. But, any considerable runtime exceeding 8000 would undoubtedly raise a red signal. I believed I had read that it was stock and clocked at roughly 7800 rpm.