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  1. #1

    Question '11 fzr IMPELLER PITCH vs RPM SHOULD I GO UP TO 23' PITCH

    AFTER fixing my broken impeller shaft because i over torqued it i was able to run her yesterday, see below for results.

    First Question is should i go to a 23degree from a 22degree pitch to bring down the rpms and increase top end?
    Second Question how much rpm would i lose going from 22 degree to 23degree pitch with my application.

    upgrades: riva enging breather kit, riva pwr filter, riva free flow exhst, riva b1 impeller, riva gen II hd impeller shaft, RD-perf R2 ecm flashing, RD perf- pump shoe kit, rite flow vents up front
    I think i could get 1 or 2 mph with proper trim up and less gas
    Boost: 10
    RPM: 8800 on PET digit 2100dx
    speed: 74.8mph on GPS,
    trim setting level
    a little above 3/4 tank of gas
    my weight is 187
    Prop: R series dynafly 13-22 155mm


  2. #2

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    First you must be in extreamly calm waters and watch the tack as the ski is at top speed to read the rpms and see what the constant numbers are, I have seen people read the max rpm numbers thinking that is what ther prop is at on rpms. These motors rev so quickly if they get the least bit of prop cavation or choppy water there is no way you should rely on the max reading. You need to retest first befor re pitching. How ever if you need to re pitch every prop pitch will change your rpm's app. 100-125 rpm's. Here is a tec tip for you open the front leading edge up to a 15* pitch first ---Tommy Jordan

  3. #3
    THE PLATE MAN JIM'S PERFORMANCE's Avatar
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    Quote Originally Posted by peterj59 View Post
    AFTER fixing my broken impeller shaft because i over torqued it i was able to run her yesterday, see below for results.

    First Question is should i go to a 23degree from a 22degree pitch to bring down the rpms and increase top end?
    Second Question how much rpm would i lose going from 22 degree to 23degree pitch with my application.

    upgrades: riva enging breather kit, riva pwr filter, riva free flow exhst, riva b1 impeller, riva gen II hd impeller shaft, RD-perf R2 ecm flashing, RD perf- pump shoe kit, rite flow vents up front
    I think i could get 1 or 2 mph with proper trim up and less gas
    Boost: 10
    RPM: 8800 on PET digit 2100dx
    speed: 74.8mph on GPS,
    trim setting level
    a little above 3/4 tank of gas
    my weight is 187
    Prop: R series dynafly 13-22 155mm
    You said you have the riva dynafly impeller there is no way you are turning 8800 rpm and only doing 74.8 mph. make sure your tach is set up right. with a stock riva impeller turning 8800 rpm. you would be in the 80 plus mph.

  4. #4
    ok will try again today

  5. #5
    THE PLATE MAN JIM'S PERFORMANCE's Avatar
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    Quote Originally Posted by peterj59 View Post
    ok will try again today
    wrap the wire around coil number 1 and set the tach at 41 and make sure you mount the tach were you can see it will doing your run don't put it in the glove box and go by max rpm you will be off.

  6. #6
    hi wrong numbers, that is everthing is correct except my tachometer readings, got 8060 confused with 8600 dah...

    I had the following readings: 7900, 8000, 8020, 8040 and 8060 i think once or twice i hit 8100
    Speeds also ranged 73.2 up to 74 .3, 74.5 all gps.
    confirmed tach reading with oem gauge.

    upgrades: riva enging breather kit, riva pwr filter, riva free flow exhst, riva b1 impeller, riva gen II hd impeller shaft, RD-perf R2 ecm flashing, RD perf- pump shoe kit, rite flow vents up front
    I think i could get 1 or 2 mph with proper trim up and less gas
    Boost: 10
    RPM: see new data on PET digit 2100dx
    speed yesterday: 74.8mph on GPS,
    speed today: see above
    trim setting level: i reached my highest rpm trimmed all the way up at 8100
    second trim setting above level i got 8020,8040,8060
    level trim: 7900, 8000
    a little above 3/4 tank of gas
    my weight is 187
    Prop: R series dynafly 13-22 155mm

    hope these numbers make more sense.
    so question still remains do i go to 23 or 24 and assuming i loose about 130revs each pitch

  7. #7

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    if you go up a pitch you will loose around 150 rpm's unless your motor has the torque to maintain it. what is your leading edge set at. i checked my skat prop which should be 13/23 and was actually 14/22. i have re pitched to 15/23. will test it next weekend. i initially re set to 15/25 and top revs were fluctating badly between 7900 and 8200 however i found the hose of the pump at the back had split. really need to re test once new hose fitted today. how is your cavitation with the solas???.

  8. #8

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    you need to get your rpm's up to 8300-8400 not down lower. I noticed you don't list a ride plate in your mods if you got a fz get a vxr plate or if it is a SHO get Jim to mod the oem one. these two things should up your top speed several mph ( 3-4 mph) Tommy Jordan

  9. #9
    i just have the oem plate, thanks, yes its the fz 2011, i can use a vxr plate for my ski
    just order a jims permformance plate from jerry of pwc, seems like that's the one hands down

    The cavitation seems minimal i dont really see it
    Last edited by peterj59; 10-12-2011 at 05:43 PM.

  10. #10

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    Quote Originally Posted by peterj59 View Post
    AFTER fixing my broken impeller shaft because i over torqued it i was able to run her yesterday, see below for results.

    First Question is should i go to a 23degree from a 22degree pitch to bring down the rpms and increase top end?
    Second Question how much rpm would i lose going from 22 degree to 23degree pitch with my application.

    upgrades: riva enging breather kit, riva pwr filter, riva free flow exhst, riva b1 impeller, riva gen II hd impeller shaft, RD-perf R2 ecm flashing, RD perf- pump shoe kit, rite flow vents up front
    I think i could get 1 or 2 mph with proper trim up and less gas
    Boost: 10
    RPM: 8800 on PET digit 2100dx
    speed: 74.8mph on GPS,
    trim setting level
    a little above 3/4 tank of gas
    my weight is 187
    Prop: R series dynafly 13-22 155mm
    My ski is identical, even the prop. I ran 79 today at 8300. I was going to go down to a 12/21. When it was warmer it was at 8260 & 78. The only diff is a jd intercooler.

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