Results 1 to 10 of 10
  1. #1

    Join Date
    Sep 2008
    Location
    Southern Maryland
    Posts
    22

    Under standing impeller pitch

    Hey looking for more advice.. I have A 2004 arx1200T3 F12-X Turbo. I Do not understand the pitch #'s. One is a 17-29 pitch and the other is a 18-30. I want to keep the same RPM But what is the difference between the two??? Is one harder on the motor than the other?? Thanks...Pat


  2. #2
    Moderator
    I build Horsepower
    NitroShark's Avatar
    Join Date
    Jan 2006
    Location
    Greenville,SC
    Posts
    1,388
    +1
    13
    The pitch is the blade angle, It's just a number for reference.

    The first number is the intake pitch, the second number is the outlet side of the props pitch. You tweak these numbers/pitches to Dial in the RPM that your engine makes the most torque at. This requires a engine Dyno to know what RPM that is or do like most and that is to lake test till you get the maximum GPS top speed.

    FYI
    You should buy the 17/29 on a stock ski in most applications.

    Shawn

  3. #3
    RonJon's Avatar
    Join Date
    Sep 2007
    Location
    Sarasota, FL
    Posts
    364
    +1
    31
    I got a question while we're on the topic: Turbo and non turbo... Honda has the smallest displacement engine that does not require a gear reduction. Their pump is big (155mm). What do they turn such a STEEP impeller?

    For example, the Kawasaki 15F has A LOT more displacement and torque, yet is uses a smaller (148mm) pump, AND has far less pitch (13/19). Can anyone explain please? Thanks!

  4. #4
    RonJon's Avatar
    Join Date
    Sep 2007
    Location
    Sarasota, FL
    Posts
    364
    +1
    31
    Also, I understand the two numbers of impeller pitch, but what is the correlation between how close or far apart those numbers are from one another?

    Example: Increasing/decreasing first number vs Increasing/decreasing second number: 13/19 vs 14/19 OR 13/19 vs 13/20

    What does changing only the first number do? What does changing only the second number do?

    Thanks!

  5. #5
    Moderator
    I build Horsepower
    NitroShark's Avatar
    Join Date
    Jan 2006
    Location
    Greenville,SC
    Posts
    1,388
    +1
    13
    The intake (suction pressure in pump terms is this area) the output pitch is what you "tweak" for RPM"

    Work on the front to feed the pump
    Work on the back (pitch in both) to get the Max torque RPM.

    Shawn

  6. #6
    Moderator RX951's Avatar
    Join Date
    Apr 2005
    Location
    League City, Texas
    Posts
    16,066
    +1
    23

  7. #7
    RonJon's Avatar
    Join Date
    Sep 2007
    Location
    Sarasota, FL
    Posts
    364
    +1
    31
    While we're on the topic: Turbo and non turbo... Honda has the smallest displacement engine that does not require a gear reduction. Their pump is big (155mm) and impeller is steep (17/29). Why do they turn such a STEEP impeller?

    For example, the Kawasaki 15F has A LOT more displacement and torque, yet is uses a smaller (148mm) pump, AND has far less pitch (13/19). Can anyone explain please? Thanks!

  8. #8
    Dave Sharp dav_dman's Avatar
    Join Date
    Aug 2005
    Location
    louisville Ky/so. IN
    Posts
    1,453
    +1
    1
    have wondered that same thing. 5 yrs ago I'd have been motivated enough to test more pitches.

  9. #9
    Bob 1tommygunner1927's Avatar
    Join Date
    Apr 2007
    Location
    Houston, Texas
    Posts
    6,362
    +1
    975
    Quote Originally Posted by RonJon View Post
    While we're on the topic: Turbo and non turbo... Honda has the smallest displacement engine that does not require a gear reduction. Their pump is big (155mm) and impeller is steep (17/29). Why do they turn such a STEEP impeller?

    For example, the Kawasaki 15F has A LOT more displacement and torque, yet is uses a smaller (148mm) pump, AND has far less pitch (13/19). Can anyone explain please? Thanks!

    Late model non-turbo'd R's & F's use a smaller pump (147mm). Anyone know if the jet nozzle from those ski's will bolt on to the larger pump (155mm) on the turbo skis (I'm assuming its smaller in diameter too)?

  10. #10

    Join Date
    Sep 2008
    Location
    Southern Maryland
    Posts
    22
    Thanks Shawn for the info. Was on travel sorry for taking so long to post back.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Impeller Pitching (Updated)
    By 1FastTrespiper in forum Sea Doo How To & FAQs
    Replies: 120
    Last Post: 07-26-2017, 07:08 AM
  2. Impeller pitch ?
    By Piney in forum 4-Tec Performance
    Replies: 5
    Last Post: 07-02-2010, 08:42 AM
  3. RXP speeds vs rpm and impeller pitch
    By Vern in forum 4-Tec Performance
    Replies: 21
    Last Post: 02-10-2007, 11:35 PM
  4. Impeller Pitch's
    By Alaska05RXT in forum 4-Tec Performance
    Replies: 3
    Last Post: 04-19-2006, 08:52 AM
  5. Impeller Pitching Questions
    By 1FastTrespiper in forum 4-Tec Performance
    Replies: 43
    Last Post: 01-04-2006, 10:28 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •