Page 1 of 2 1 2 LastLast
Results 1 to 10 of 11
  1. #1
    pass1's Avatar
    Join Date
    Apr 2009
    Location
    Gatineau, Canada
    Posts
    423
    +1
    5

    fuel requirement for ''A'' kit.

    Hi guys!

    Just wondering if a stock 2008 rxt-x (stock ecu and stock 42 lbs injectors) could handle a rotax racing ''A'' kit supercharger (11.5 [email protected]) without any mods.
    I know a stock x-charger boost 10 psi, so wondering if it will handle the extra 1.5psi without mods.

    Thanks!!


  2. #2
    boost junkie skidoochris's Avatar
    Join Date
    Mar 2012
    Location
    Davison, Mi
    Posts
    4,494
    +1
    476
    I would add a rrfpr and a good afr gage

  3. #3
    RXP 260 X Short Course Veteran RXP244's Avatar
    Join Date
    May 2007
    Location
    Auckland, New Zealand, New Zealand
    Posts
    1,244
    +1
    104
    I ran a Les Cooke A wheel (just over 10 pound) @ 8100rpm on a stock 215 ECU with 42's for a long time. No RRFPR. Ran 12.4 AFR's all day long.

  4. #4
    Avi8tor's Avatar
    Join Date
    May 2012
    Location
    Greenville, NC
    Posts
    826
    +1
    27
    First I have no experience with this setup and Do not know answer...

    .
    My understanding is that stock setups are ran lean. ( some have quoted as high as 13.00 afrs on stock [email protected] wot, I dont know as I've never had a afr gauge on stock engine) If you increase boost without changing anything else you may be pushing it too far. Perhaps the ecu can compensate, I don't know.


    Couple things to consider
    When mark rxp244 added 42 injectors on stock 215 ecu setup, he went from (guessing) 38 to 42 injectors effectively increasing the fuel. You will be increasing boost with no increase in fuel since the x boat maps are already mapped for 42 injectors.

    1st thing I'd do at minimum is to add a good afr gauge to see where you are.

    You could add fuel with a rrfpr , or cmd (what Im using), have your ecu remapped or even install a 215 ecu mapped for 38 inj like Mark did.

    No matter your choice.. get a good afr gauge

  5. #5
    RXP 260 X Short Course Veteran RXP244's Avatar
    Join Date
    May 2007
    Location
    Auckland, New Zealand, New Zealand
    Posts
    1,244
    +1
    104
    Quote Originally Posted by Avi8tor View Post
    1st thing I'd do at minimum is to add a good afr gauge to see where you are.

    You could add fuel with a rrfpr , or cmd (what Im using), have your ecu remapped or even install a 215 ecu mapped for 38 inj like Mark did.

    No matter your choice.. get a good afr gauge
    Solid advice.

    Before I started modding any part of my engine all those years ago with my RXP, the very first thing I did was get myself a AFR gauge. I never changed one thing that would affect fueling until I knew what affect the changes I was making were having.

    I do think that adding a RRFPR would be all that you need to assure that you have enough fuel at WOT. BUT! How will you know without a AFR gauge.

    I would add the RRFPR, I think you will be able to lower the base pressure a tad and with the 42's you have more than enough fueling up high. Just get that AFR sensor in there and you'll be good to go. You don't have to run the sensor all the time. I never did. I just used it to tune for correct AFR's after making performance mods and once AFR's were right again, removed it completely from the ski. But now with Gauges like the MTX-L from Innovate it's easier to run them permanantly on the boats.

  6. #6
    RXP 260 X Short Course Veteran RXP244's Avatar
    Join Date
    May 2007
    Location
    Auckland, New Zealand, New Zealand
    Posts
    1,244
    +1
    104
    Quote Originally Posted by pass1 View Post
    Hi guys!

    Just wondering if a stock 2008 rxt-x (stock ecu and stock 42 lbs injectors) could handle a rotax racing ''A'' kit supercharger (11.5 [email protected]) without any mods.
    I know a stock x-charger boost 10 psi, so wondering if it will handle the extra 1.5psi without mods.

    Thanks!!
    I am also thinking that an extra 1.5psi of boost is going to make bugger all difference and at that level of boost you are probably ok to run mid to high 12's AFR's. You just won't know until you get a AFR gauge on it.

  7. #7
    SLASHER's Avatar
    Join Date
    Jun 2007
    Location
    Australia, Perth WA
    Posts
    3,263
    +1
    474
    Iam running a ET 127 wheel on a 08 RXTX and no problems ... They are similar to an A wheel ...

  8. #8
    RXP 260 X Short Course Veteran RXP244's Avatar
    Join Date
    May 2007
    Location
    Auckland, New Zealand, New Zealand
    Posts
    1,244
    +1
    104
    Quote Originally Posted by SLASHER View Post
    Iam running a ET 127 wheel on a 08 RXTX and no problems ... They are similar to an A wheel ...
    There you go.

    But are you monitoring your AFR's. I take it you are?

  9. #9
    Avi8tor's Avatar
    Join Date
    May 2012
    Location
    Greenville, NC
    Posts
    826
    +1
    27
    Hey Mark... do you remember what afrs were at wot on stock engine ? That was smart to get a baseline before mods.

  10. #10
    lazsrxp's Avatar
    Join Date
    Oct 2012
    Location
    Miami
    Posts
    460
    +1
    3
    What AFR gauge you guys recomend? Where can i get one? How hard is it to install

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. Fuel octane requirement for STX 15F? Ethanol concerns?
    By Dalts72 in forum Kawasaki Open Discussion
    Replies: 5
    Last Post: 06-19-2015, 07:23 AM
  2. Fuel requirements for gtx supercharged?
    By scottie mac in forum 4-Tec Performance
    Replies: 2
    Last Post: 04-05-2010, 01:25 PM
  3. Fuel Requirements for X-Charger
    By Antiguan FZR in forum 4-Tec Performance
    Replies: 94
    Last Post: 08-31-2009, 07:12 PM
  4. c-kit on stock ECU fuel requirments?
    By Turbo Nick in forum 4-Tec Performance
    Replies: 8
    Last Post: 09-12-2008, 01:35 PM
  5. What fuel requirements for X-charger with XS intercooler?
    By MPower in forum 4-Tec Performance
    Replies: 17
    Last Post: 04-08-2008, 11:21 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
  •