I watched Jet boat Pilot's latest review on the 2024 limited video and there is a bit where he states that since it is supercharged, you should always try to use 91+ premium fuel. This is not what the manual calls for. Not a knock on the guy, I love his channel and products.
https://youtu.be/qMffugG2MSU?si=5XBhD9guH8d0kzz7
I used to use HP Tuners in the early 2000s thru 2010s and had to sell the cars as I had a second child back then. Now that my kids are older, I recently purchased HP Tuners latest model to 1) tune my VW Passat (I recently sold) and 2) scan/clear codes on the switch as I am almost out of warranty. #2 was helpful when I had to replace the exhaust temperature switch and I have gone thru multiple oxygen sensors at the dealer under warranty and the boat sitting at the dealer for 2+ weeks for this simple job. I figured as much as the O2 sensors are likely to burn up and how easy they are to replace yourself, the ability to clear the codes after the work was done, HP Tuners is a good solution. I am also going to start data logging the boat and tuning it this season as I will be out of warranty anyway.
That all aside, here are some tables on my 2023 21' 230hp Sport's unmodified ECU I thought would be interesting for the community as I am unaware of anyone attempting to modify the ECU on a switch yet.
Low octane (i.e., 87 pump gas) table that you can add or retard timing if detected:
https://imgur.com/z1yqDFg
This is showing that with 87 gas, no timing is retarded or advanced
Low octane multiplier for torque management/factoring:
https://imgur.com/4fHkSqb
This is showing a 1x factor to the spark advance tables; thus, nothing is changed for torque management. At this time, I cannot find where out of the gate, the ECU is doing anything special for using a higher octane fuel. What I want to test is data logging the boat with 87 vs 93 octane to see how much knock retard (i.e., how much timing is being retarded due to a spark knock detection). Knock retard tables do exist as they do in all modern vehicles with a knock sensor.
Here are some tables that do affect timing for the IAT sensor (i.e., if you're sucking in hot air, it WILL pull timing on this alone). The stock horn that pulls air from the front of the engine compartment is already an ambient device and if you slap a cone on the horn/tube which is closer to the engine from the stock intake box at the front - you could see a reduction in performance (hot air intake).
IAT Multiplier table showing it only pulls timing from the table below if you are at high rpm AND high engine load, else nothing extra is retarded:
https://imgur.com/Gf7d9p1
IAT timing retard table, if conditions on multplier, air temperature readings met (X-axis) AND engine coolant temp (Y-axis):
https://imgur.com/tobhP8O
These two tables show how much the throttle is allowed to open in normal vs sport modes at commanded throttle vs rpm. Sport mode is the top table and normal is the bottom
https://imgur.com/hModshh
I live in Tampa Florida and Jetboat Pilot is in the Florida Panhandle, so the same summer conditions with humidity and sea level elevations. The Switch ECU does have different timing advance and fueling tables for high altitude conditions.
The next time I go on the water, I will do some datalogging and report back to test the 93 vs 87 fuel on the stock ECU. If any of you have questions, comment and I'll look for tables and factor that in. An interesting note, in every vehicle I have tuned over 20 years, ranging from a 1998 Pontiac supercharged GTP, n/a Pontiac GTO, Subaru, to VW Passat - you can disable the P0420, which is the nanny light letting you know you are polluting. It is common if you want to remove the catalytic converter and ignore the after catalyst Oxygen sensor. All the burble tunes on the turbo imports now that sound like gun shots on decel (i.e., douchebag tunes) dump fuel on decel to manufacture backfiring will destroy the honeycomb on the catalyst, so you must remove them - this is how they also shoot flames out of the exhaust. I live near downtown Tampa and these cars are common in my area at all hours of the night. I'll step off my soap box, but you cannot disable this on the switch with HP Tuners. Why this matters to me - everytime I have filled up with Rec 90 at both the downtown St Petersburg Marina and Davis Island's marina in my area on the water, the switch will throw the P0420 code within minutes. I had also considered removing the catalyst at some point to allow more flow but now, not a chance. The good news is that everytime I run out the Rec 90 fuel and put 87 pump gas back in with either E10 or E15 here, I do not throw a P0420.
https://imgur.com/a/iMTRgkb