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  1. #11
    What is required to tune the ecm?

    What did Kawi change to make room for the extra stroke on the 15F?
    A keep the same pin height as the 12F piston and use a shorter rod?
    B Keep the same pin height as the 12F piston and make the cylinders longer?
    If the 12F piston in a drop in the pin height must be the same or the piston is DEEP in the hole on the 12F.

  2. #12
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
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    Quote Originally Posted by TT350 View Post
    What is required to tune the ecm?

    What did Kawi change to make room for the extra stroke on the 15F?
    A keep the same pin height as the 12F piston and use a shorter rod?
    B Keep the same pin height as the 12F piston and make the cylinders longer?
    If the 12F piston in a drop in the pin height must be the same or the piston is DEEP in the hole on the 12F.

    12f and 15f pistons use the same wrist pin height, its the same as the zx12r.

    The cylinders (12f and 15f) are the same height

    The 12f rods are longer and thinner.

    55.4mm stroke vs 69.2mm stroke.

    12f pistons fit the 15f and raise compression to like 14:1 with the longer stroke. Riva used to use that as their endurance kit. It required ms109.

    Tuning the ecu is semi-proprietary. I have a pisani serial suite and can move tunes around and can view the files but I don't have a full mask to know what the maps actually look like. Someone with more experience on map discovery than me can probably dig into them more but I can't comment.

    Sean

  3. #13
    dcuhpw's Avatar
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    There was a subject posted on here called “hacking the LX ecu” or something to that effect and he was able to dig deep into the ecu and see the actual maps I believe. For your project I would probably just go with a stand alone efi setup if you want to go that far and have full control over you fuel and timing maps.

  4. #14
    Ok that makes since how the pistons interchange.
    So Kawi has the ecm on lock down. It would be nice if there was a HP tuners type software to tune it with like the LS1 cars and trucks
    Last edited by TT350; 08-14-2020 at 11:10 PM.

  5. #15
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
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    Quote Originally Posted by TT350 View Post
    Ok that makes since how the pistons interchange.
    So Kawi has the ecm on lock down. It would be nice if there was a HP tuners type software to tune it with like the LS1 cars and trucks
    The ecu isn't locked, we just don't have a map or mask made to readily identify the maps and their functions yet. I have probably 10 stock maps saved plus the endurance/offshore and some of the vortech maps saved. I can move them between any of the pre 2013 ecus. Post 2013 there is a different temp circuit on them so it messes with the temperature sensor readings if you flash them.

    Sean


  6. #16
    Been thinking about this. I hate to walk away from displacement but I think the 15F rod on a shorter 12F stroke crank will give me some pin height to work with.
    A forged 9:1 motor with a 15F intake and 15F or ZX12R cams with a ported head 10lbs of boost for a Rotrex C30 and tuned with a standalone 200HP @ 8500 would be pretty sporty.]

    https://rotrex.com/wp-content/upload...-C30-Range.pdf

    My buddy let me ride his 90mph GP1800R. It was SINK FAST! Way to much for me. I know I can buy a modern ski that will out preform this comb but I'll have fun playing with something I built.

  7. #17
    dcuhpw's Avatar
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    Quote Originally Posted by TT350 View Post
    Been thinking about this. I hate to walk away from displacement but I think the 15F rod on a shorter 12F stroke crank will give me some pin height to work with.
    A forged 9:1 motor with a 15F intake and 15F or ZX12R cams with a ported head 10lbs of boost for a Rotrex C30 and tuned with a standalone 200HP @ 8500 would be pretty sporty.]

    https://rotrex.com/wp-content/upload...-C30-Range.pdf

    My buddy let me ride his 90mph GP1800R. It was SINK FAST! Way to much for me. I know I can buy a modern ski that will out preform this comb but I'll have fun playing with something I built.
    200 HP is NA numbers in these engines. If you want to run 250+ then do forced induction. Otherwise just stick with NA.

  8. #18
    My name is Sean and I am addicted to STXs smokeysevin's Avatar
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    A 15f with 17psi will run 400ish hp. 10psi would be 220-270 depending on chager type and supporting mods.

    Sean

  9. #19
    I have been looking at forged pistons for the 250-310 Ultras. I know that cam profile sensors and manifolds are different in the SC skis vs the N/A skis. How much is interchange from the 1500 N/A motor to the SC motor? If there is a book that has specs like deck height rod length and so on I’ll buy it. I come for the automotive drag racing world. I know where to find this stuff and use it to build combos for various performance goals.

  10. #20
    Let me out of here......I need to go on Greenhulk!
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    I think the Ultra cylinder is 7mm taller than the 15f. Why did you need to interchange ? Just get the custom pistons for the 15f spend your time and money on other stuff like the pump.

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