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  1. #1
    Live Fast wave15stx's Avatar
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    differnce in speed with timing?

    Over the years I've ran several vtech tunes right now I'm running a tune with 32 degrees of timing im wondering what kind of speed differences any of you saw from let's say 32 degrees timing to 36 degrees if any.


  2. #2
    Branden's Avatar
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    i run my ski at 33 degrees and saw very little increase when i bumped it to 34 so i put it back to 33. What i have learned over the years is this, the motor will tell you when its happy or not, if you add a degree of timing and it picks up a bit of MPH the motor liked the increase, if no speed is picked up or a loss the motor is pissed off. The objective should be to run the least amount of timing as possible to make the motor happy. It is trial and error to see what your individual setup likes. Just my .02

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    JT jpt7779's Avatar
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    We have several guys running turbos in the mid to high 80's with 29-30* timing. What does that tell ya?

  5. #4
    Live Fast wave15stx's Avatar
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    Quote Originally Posted by jpt7779 View Post
    We have several guys running turbos in the mid to high 80's with 29-30* timing. What does that tell ya?
    perfect example of what I was lookin for thanks man

  6. #5
    its not a perfect example and i try to explain why.
    To make it simple, the more you boost the more you need to retard the ignition.

    In a turbo setup you can turn up the boost and then you need less ign to make the same rpms.

    If you got a compressor setup you are usually stuck with the same boost level depending on you wheel.
    So you usually got less boost on the same rpms as a turbo would have.

    So a bit harder to compare.

    But we did a test.
    Customer with a 137+4 wheel , we started on 33 degree of ignition and for every ignition degree we added we got 100 rpms more.
    With the data logger we could see where it was safe to stop.
    In this ski we set the ignition angle to 35 degrees.

    If you raise the ignition angle to much , the ecu will start to reduce it automatically, and you get no further gains.

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    JT jpt7779's Avatar
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    And this is exactly why there have so many people destroying engines cranking up the timing not knowing WTF they are doing by not data logging and understanding the consequences. We all think, "more is better", well in this case that is not necessarily true.

    Yes you can go from 32 to 36* timing, but you better be paying attention to Knock signals, data logging numerous channels, and understand what you are doing.
    Last edited by jpt7779; 05-19-2015 at 09:05 PM.

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    Branden's Avatar
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    or learn how to read a spark plug like this idiot

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    jim

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    Quote Originally Posted by jpt7779 View Post
    We have several guys running turbos in the mid to high 80's with 29-30* timing. What does that tell ya?
    higher the boost, the lower the timing to run a certain octane safely?

    AND "these" turbo skis are running boost higher than 15 psi on pump fuel?

  11. #9
    boost junkie skidoochris's Avatar
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    over 15 at wot is not a problem (I have run 18 )
    its the 15 ish in the lower rpms (about 7000) that is where the best area for knock

  12. #10
    Bob 1tommygunner1927's Avatar
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    Quote Originally Posted by wave15stx View Post
    Over the years I've ran several vtech tunes right now I'm running a tune with 32 degrees of timing im wondering what kind of speed differences any of you saw from let's say 32 degrees timing to 36 degrees if any.
    In addition to the other points made, the limiting factor for ignition timing is the fuel, and also the retail point of sale. 32 degrees of timing is a good safe level of timing for old gas, or wrong octane gas. The higher the timing the less room for error.

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