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  1. #1
    Jerry, Jerry, Jerry jerryspringer's Avatar
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    AFR/FUELING confused? please help

    confusion has kicked in ..

    im going to add 15 psi charger and intercooler (probably new fizzle unless others believe better options are available)
    im running 07 with Les Cooke Seadoo Centre 8650 ECu , Seadoo centre retainers, 4 inch air, 42 inj , 629 cam , x charger

    with the addition of cooler and charger i obviously need to look at fueling and AFR

    so far al mods have been bolt on and easy ... but now , i feel like a newbie - i see all these options for feuling which leaves me with all sorts of questions

    i see ppl running begi, rising fuel rate regs, modded fuel rails, (some have all) some with walbro pumps, some have fuel controllers ? is this all required.. does version replace another - eg run either begi on its own, run fuel controller on its own ,


    anyone able to give me a quick lesson on how and what all this does or point me in the right direction - i d rather do my homework than have my engine hand grenade...


    thnaks


  2. #2
    boost junkie skidoochris's Avatar
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    you need to make a list
    what fuel are you going to use
    what type fuel and cam is your ecu mapped for
    are the injectors you plan on using the same as the ecu map
    is your ecu mapped for 15psi
    does your ecu still use the knock sensor
    the closer you are to the correct fuel map the less other mods needed

  3. #3
    Fast & Loud meeper's Avatar
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    you should have been looking at AFR with those mods, you are very luck thus far. even with those mods on that ECU that is not enough fueling up top

    i would figure out if the ECU is mapped for 42s or 38s and either way go with a return style fuel system using a regulator for idel rpm AFR and Begi for mid and top end afr adjustment..... all mechanical nothing electrical to fail on you..

  4. #4
    Moderator beerdart's Avatar
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    The Begi is purely mechanical fuel enrichment and you can only tune three parameters "Idle, Mid, and Wot". The fuel controller is electronic with infinite tuning range. . With the advancements in the fuel controllers with auto tune is hard to beat it.

  5. #5
    Jerry, Jerry, Jerry jerryspringer's Avatar
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    Quote Originally Posted by beerdart View Post
    The Begi is purely mechanical fuel enrichment and you can only tune three parameters "Idle, Mid, and Wot". The fuel controller is electronic with infinite tuning range. . With the advancements in the fuel controllers with auto tune is hard to beat it.
    i found a post - power commander CMD marine - and it talks about auto tune which sounds fantastic.... but i wanna make sure i ve got this right, if i purchased a power commander , could i add a et 137/RIVA XX/b kit charger etc + fizzle intercooler to my 07 rxp (8650 Seadoo Centre ecu, 629 cam, 42 inj and 4 inch air) and the cmd would auto calibrate AFR mixtures Do i still install a AFR gauge, would i then need a rising fuel rate regularator to increase flow?? or does the CMD do it all and compensate?

    My ECU has been mapped for 42 inj , would be best to put in 48's and then let CMD unit auto tuned accordingly -
    Will this change the ecu remapped settings done by Seadoo Centre?
    Last edited by jerryspringer; 09-28-2012 at 10:03 PM.

  6. #6
    boost junkie skidoochris's Avatar
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    48lb will run richer at the same boost
    the ecu map never changes
    the cmd map makes changes the ecm map
    AFG is a must for the auto tune
    if your AFR stay in the safe zone you may not need a rrfpr (not likely)
    and if you buy bigger injectors like 60lbs you should not need a rrfpr
    with out a rrfpr at 15psi boost a injector at 58psi will only flow fuel at 43psi rate
    Last edited by skidoochris; 09-28-2012 at 10:33 PM.

  7. #7
    Jerry, Jerry, Jerry jerryspringer's Avatar
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    Quote Originally Posted by skidoochris View Post
    48lb will run richer at the same boost
    the ecu map never changes
    the cmd map makes changes the ecm map
    so would it be safe to run 42's and the cmd with add the correct fuel ?

  8. #8
    HardmanGT's Avatar
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    check my sig. I run an XX with a Riva ECU, Fizzle intercooler, RRFPR (ref line attached) and Bosch 48's with the CMD with Autotune. 14.5 pounds at 8500. Zero issues and it runs perfectly!

  9. #9
    Avi8tor's Avatar
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    Running the cmd without rrfpr you need much bigger injectors than with the rrfpr. For example I run 60lb injectors with my xcharger and 80lb with my rude2 (and xcharger if I want)

    The way I understand fuel pressure is this ( and someone who knows more correct me if I am wrong) . A 1to1 rrfpr keeps your feel pressure constant even though boost is occuring in your manifold. Running stock fuel pressure 58 psi with no rrfp and 15 lbs boost you effectively have 43psi of fuel pressure going into engine. (58-15=43) so you need a much larger inj when running without a rrfpr.

    The cool thing about the cmd and autotune is that you can have way big injector to cover your WOT, and reduce duty cycle on it so you have great afrs at idle mid and all the points in your fuel curve.

  10. #10
    HardmanGT's Avatar
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    spot on explanation!

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