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Thread: stock Ultra AFR

  1. #1

    Thumbs up stock Ultra AFR


    I'd like to know what are your stock AFR ratio, for those who have measured it...

    What is the leanest AFR ratio you've tested before Boubadaboum ? and at what boost pressure...


  2. #2
    Go Hard or Go Home FraggleRock's Avatar
    Join Date
    Jul 2007
    Perth (Western Australia)


    Hey Whooper what's your Location? I dont know what the leanest AFR is but it would depend on your location/altitude for sure.
    Last edited by FraggleRock; 01-29-2008 at 09:32 PM. Reason: typo

  3. #3

    Thumbs down ?

    Quote Originally Posted by FraggleRock View Post
    Hey Whooper what's your Location? I dont know what the leanest AFR is but it would depend on your location/altitude for sure.

    I'm from france. Stock AFR may vary from one location to another, but it's not significant. taken into account 1.498cc, 250 HP at 7650 rmps, 11.4 psi boostpressure, 43psi fuel pressure with 375cc should be possible to find the theorical AFR.

    I'll find it one my own, there are plainty of soft to do that job. J just regret that those who sell pulleys, and other pretented "racing parts", do not share this information. I do respect that attitude, but, i cannot understand why they sell their stuff, without giving all information.

    my fault to have trusted those people, who appear to me to definitely pretend helping others, but are only interested in there money...
    That's a typical american attitude, isn'it ?

  4. #4

    Join Date
    May 2007
    Orange County, CA
    Funny, that response sounds like the typical view of the French towards America.

  5. #5
    The question you asked is for the non variable that any tuner web site has the answer to. the question I think you probly asked is what size injector do I need to get the fuel AFR spectrum from idle to WOT correct that will tune with in the limits of the ECU mapping at a certain boost level for a 1.5 liter motor with 43 lbs of fuel pressure.

    Anyway to answer your question

    The AFR that any motor needs to run right with non turbo boost is as follows.

    The ultra motor follows these numbers perfectly!
    Stock Idle is 10.5 to 11
    cruise at 2000 - 5000 rpm is around 13ish
    WOT IS 11.2 TO 12.7

    Badaboom happens real easy at 13 and up when WOT
    Cruising you can go as high as 14.5

    your idle will be the most efficiant at 14.7 AFR but the fuel will be way to lean and stumble when you stab the throttle. thats why most non turbo boost applications run low idle AFR numbers

    But on another note most people that build race engines know all this stuff anyway. It's like common sense for tuning nowadays
    Last edited by snapper455; 01-30-2008 at 04:37 PM.

  6. #6

    Join Date
    Jul 2005
    Lake Dunlap, Texas
    If it were'nt for the "typical Anerican attitude" all you French dudes would be having to speak German.

  7. #7
    Beagleman62's Avatar
    Join Date
    Mar 2007
    Richmond, Virginia
    I think he needs to take a trip to Normandy and look at all the graves of American soldiers. I guess that could be the "American attitude"

  8. #8
    English Bob's Avatar
    Join Date
    Jun 2007
    Southern UK
    Quote Originally Posted by Beagleman62 View Post
    I think he needs to take a trip to Normandy and look at all the graves of American soldiers. I guess that could be the "American attitude"
    Count yaselves don,t have to live nextdoor to em.....

    Hey Beags....who found the Enigma machine????? J.K..(Films)..

    all in good taste......Bob....

  9. #9
    This is the same guy who came onto TeamMoto and posted this.

    Whooper Says:
    August 31st, 2007 at 10:38 ame
    This is all theory…
    cause in the facts, the fresh water cools down FIRST the intercooler THEN…goes into the exhaust. The big problem you re going to encounter, is you may burn the exhaust “pipe” which temperature is going to dramaticaly get higher…
    The new water lines you gave are wrong.. I’m sorry to tell you. I just hope those who ve trusted your tip, won’t break their engine cause it may cost you a lot…
    best regards
    1. Skip Says:
      September 3rd, 2007 at 9:23 pme
      I am not responsible for people who try to duplicate me. Thats completely on them.
      I am to assume that you have mistaken the post. The water routing is actually opposite as to how you described it.
      Please refer to your service manual page# 9-14 which CLEARLY shows the water flow directions. Once you have studied this you will see that the exhaust manifold has two exit points. One flushes the I/C {red on photo} and one flushes the exhaust {not colored on photo}
      The kit simply routes the hot water coming from the exhaust pipe to the outside and not the I/C. This direct exit allows for faster flushing of the exhaust manifold and eliminates the hot water from flushing the I/C.
      If there is anything else that you may be concerned about then please feel free to address them here. Thank you for your input and the opportunity to clearly explain in more detail the water routing.
      Your friendly information provider.

    He didn't know his stuff then and he still ain't got it figured out, he's been hating the fact the the USA is leading the world in performance 250 stuff. Shit even Nicolis Rius came back from France to the USA to build his 250X for the Guadeloupe race. Whats that tell ya.

    Every time he says something its to bash on someone. Instead of asking he tells ya your wrong. Damn do I sound like this guy too if so just shoot me.

    My data colletion has shown vary close to Snappers. I didnt want to answer Whooper cause I fely it was a set up question so he could jump all over my findings and do his typical routine.

  10. #10
    Silence! I Keel You! earthshaker's Avatar
    Join Date
    May 2007
    Northern CA Coast
    Alrighty then....

    I guess i'll follow up with this:


    What have you found in improving performance to the 250X? It seems you have a little history traight you might need to address and elaborate on what "racing parts" like pulleys are non performers/income generators. In other words, what have you bought, tested, and found to be crap or what info do you have to back up your statement? I'm actually not trying to set you up, rather, bring you to the podium.

    IMHO, as an example, a slightly smaller pulley will increase boost and performance to an extent, granted if you don't toss or calibrate the stock BOV it won't do much of anything for you - let alone injectors fuel rating, etc.. I can here you say AH HA!...."that's a good example of what i meant about the mfg's not providing performance info." I'll agree here to a point. Hiding behind the liability can create skepticism about the actual performance of a product.

    This started out to be a good thread with a good question, unfortunately it seems to have brought up a WW. I personally have been very interested in HONEST info on the stock AFR readings and then also detailed logs with what hardware combinations/modifications some of these tuners/racers found.

    I vote new thread started by Snapper if he's willing. Then maybe some other racers will chime in to speed the learning curve for the speed hungry rec riders.
    Last edited by earthshaker; 01-31-2008 at 03:25 AM.

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