Page 1 of 2 1 2 LastLast
Results 1 to 10 of 18

Thread: Injector size ?

  1. #1

    Join Date
    Aug 2008
    Location
    Denmark,Europa
    Posts
    341

    Injector size ?

    How big injectors will i need to use?

    I will be running 2rude or et 68-140,xs intercooler,4" front intake,rrfpr,stock ecu,air is 60-80F,water is 55-65F.

    And what grate and impeller would be the best to use?,i am not looking for the last 1-2 mph in topspeed as we always ride in chop,i prefer acc. and holeshot.

    Thanks.


  2. #2
    Moderator Snoman's Avatar
    Join Date
    Apr 2006
    Location
    South Chicagoland
    Posts
    14,688
    +1
    846
    I would think you would be fine with 50# injectors..You are still gonna want to check your A/F once you install them..

    Grate??? I would recommend Rivas..
    Impellor??15/20r or a 15/22r..But you will have to tweek them...

    I tried a 15/20 3 blade and was impressed with that too..That may be an option if your looking for hole shot and not top end...This with a 83 mm ring and youll have a real nice hole shot..

  3. #3
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    Quote Originally Posted by lars k View Post
    How big injectors will i need to use?

    I will be running 2rude or et 68-140,xs intercooler,4" front intake,rrfpr,stock ecu,air is 60-80F,water is 55-65F.

    And what grate and impeller would be the best to use?,i am not looking for the last 1-2 mph in topspeed as we always ride in chop,i prefer acc. and holeshot.

    Thanks.
    Hello lars K,

    My last setup on RXP was stock ecu and 2Rude.

    You can see all my testings with results and AFR readings etc, at
    "Tested new mods with results"

    If you run 42's you will have the fuel pump maxed out with RRFPR wide open with a lean AFR.

    With 50,s you will have the RRFPR at low seting, so will have room to adjust up but not much room to adjust down.

    You dont want your RRFPR any lower then 42 and no higher then 62 to be in good range.

    Check out my thread for actual AFR readings, but IMO in a perfect world and summer heat 48's should be perfect and 50s will work.

    As far as grates, i have only ran a riva as it performs best per my drag style. Others that ride in ocean will probably say R and D or Worx.

    Go with a 15/20 or 15/22 (does not matter) on 4 blade prop and a 15/19 if you want a 3 blade prop. Then get prop pitched per your rpm via conditions.

    Good Luck!!!

  4. #4
    speedskixp's Avatar
    Join Date
    Feb 2008
    Location
    venice fl.
    Posts
    8,117
    +1
    120
    With the 48's and stock ecu and rrfpr I am maxing out my fuel pump in the cool weather at sea level with the ET to get my A/f to 12.1. If your running stock ecu and et 68-140 I would go with 50's. I'm not sure about the 2 rude or your climate conditions.
    I may need to borrow Stevens 50s to test while his boat is apart.(hint)

  5. #5

    Join Date
    Aug 2008
    Location
    Denmark,Europa
    Posts
    341
    I am thinking about buying one of these + the fuelpressure unit.


  6. #6
    Nothin' better than Doo'in it! BigDaddyRXP's Avatar
    Join Date
    Aug 2007
    Location
    Tampa Bay, FL
    Posts
    9,202
    +1
    673
    Good topic as I'm hunting for a set of 42# injectors

    Any hot deals on these anywhere

  7. #7
    speedskixp's Avatar
    Join Date
    Feb 2008
    Location
    venice fl.
    Posts
    8,117
    +1
    120
    Quote Originally Posted by bigdaddyRXP View Post
    Good topic as I'm hunting for a set of 42# injectors

    Any hot deals on these anywhere
    Place a WTB add in the classifieds.

  8. #8
    speedskixp's Avatar
    Join Date
    Feb 2008
    Location
    venice fl.
    Posts
    8,117
    +1
    120
    Quote Originally Posted by lars k View Post
    I am thinking about buying one of these + the fuelpressure unit.

    Absolutely! How much is that unit?

  9. #9

    Join Date
    Aug 2008
    Location
    Denmark,Europa
    Posts
    341
    Quote Originally Posted by speedskixp View Post
    Absolutely! How much is that unit?
    A bit pricy,around 400$+100$ for the fuelpressure unit (Ebay)

  10. #10
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    Quote Originally Posted by bigdaddyRXP View Post
    Good topic as I'm hunting for a set of 42# injectors

    Any hot deals on these anywhere

    sorry to get off topic, but a got a new set that i ran for 5 hours or so on my 2 Rude that i just realized I dont need anymore with my ecu setup now. PM what you will be willing to pay for them.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Injectors size?
    By lars k in forum 4-Tec Performance
    Replies: 7
    Last Post: 05-22-2009, 12:11 AM
  2. What injector size does a Rotax Racing ECU expect?
    By boostaholic in forum 4-Tec Performance
    Replies: 7
    Last Post: 07-24-2008, 01:24 PM
  3. x model stock injector size?
    By [email protected] in forum 4-Tec Performance
    Replies: 11
    Last Post: 06-02-2008, 02:26 PM
  4. Fuel injector size discussion (interest to turbo guys)
    By engineermike in forum 4-Tec Performance
    Replies: 15
    Last Post: 12-28-2007, 10:41 AM
  5. Injectors Size On X Series??
    By jimjim in forum 4-Tec Performance
    Replies: 4
    Last Post: 09-15-2007, 05:04 PM

Posting Permissions

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