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  1. #1
    NOONZ's Avatar
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    Oct 2009
    Location
    Port Stephens, NSW, Australia
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    81

    Thumbs up Gained 120+ RPM's!

    Hey guys,

    I ALWAYS run a minimum of 98 octane fuel but decided to change fuel stations and gained a very noticeable difference! I used to swear by BP fuel but decided to try Shell Optimax, wondering if anyone else in Australia had similar results? I also used engine tuner that is a BRP product that de-carbonize your upper cylinder! Went from best of 8480 to 8620 .


  2. #2
    monaroman76's Avatar
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    Mar 2008
    Location
    Whyalla, South Australia
    Posts
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    I only ever use BP ultimate or Optimax, can't say I've ever noticed one to be better than the other. But all the same, good stuff

  3. #3
    optimax was great in my car, but down here in Vic we get Vmax

  4. #4
    I will have to give it a go, I have only been using caltex vortex 98..

  5. #5
    shrabber's Avatar
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    Apr 2008
    Location
    Jacksonville, FL
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    Weather

  6. #6
    ADAMBOMB's Avatar
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    Mar 2006
    Location
    Sunrise,Florida
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    Quote Originally Posted by shrabber View Post
    Weather
    +1

  7. #7
    hero's Avatar
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    Feb 2011
    Location
    Australia sydney
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    331
    Quote Originally Posted by shrabber View Post
    Weather

  8. #8
    Hydrotoys's Avatar
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    Jul 2005
    Location
    Mesa, AZ
    Posts
    16,712
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    85
    Fill the top part in, for your specific location. Keep a small journal in you truck with what your max WOT rpm's were that day. You'll be amazed by the variances with weather.

    -higher elevation, lower rpms.
    -higher humidity, lower rpms.
    -lower barametric pressure, lower rpms.
    -higher temps, lower rpms.

    Some folks talk about it in relative density. It's easier for me to remember using relative altitude.
    http://www.hydrotoys.com/wavs/pda-de...a-denscalc.htm

  9. #9
    HORSEPOWER JUNKIE 9secZO6's Avatar
    Join Date
    Jun 2007
    Location
    Belle Chasse, La.
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    2,006
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    We call it density altitude (DA) and u can see 400-plus rpm change from one day to the next if we go from hot, sticky air to cold dry air such as a cold front having just moved in bringing high barometric pressure as well. A lot of testing results are off because this very important data is ignored during testing. Someone here sent a text my way last Wed to tell me we had great DA at the track that night. Around here we pray for #s like -2500ft or even lower (-3500 = lower)

    Engine dyno computations account for DA, but your speeds on the water and times on the track do not.......

  10. #10
    Hydrotoys's Avatar
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    Jul 2005
    Location
    Mesa, AZ
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    85
    2000ft for my normal riding area is a dream. I actually had a sub-500 day in the middle of winter one year when I hit a high, with a low temp, and nearly 10% humidity. Pretty sure I stuck a piston that day.

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