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IGNITION: What does ignition timing really mean?

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    #16
    Looks about right Denis. Now show us 5500 RPM

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      #17
      HAH! 20 degrees on the limp fisted pixie dust that we call petrol?! The highest we get here is 91 octane and I dont know how accurate that is.
      Going any bit above 17 will get knock, Using a det can you can hear it.. If you can hear detonation in the car that is REALLY BAD detonation.
      You could run 20 but the car would have to be pig rich. Having a richer mixture slows the burn down enough to stop detonation. If you retard the timing too much you will have very high egts and basically melt the side off one of your valves. A guy I know burnt a valve out of his engine like that, I checked his fuel map in his Megasquirt and he was running 8.. Count em.. EIGHT degrees timing under full load at 17 psi. .If your going below 15 degrees then your getting too low. Bring the timing back up and add some fuel to slow the burn down.

      More timing isnt always a good thing either. It was generally thought that the more timing you add the more power youll make. This might be true under full boost since its unlikely youll be running gas with a high enough octane to reach its best possible torque but when it comes to an off boost situation or a N/A car as you add timing you will get a torque increase and then it will reach a peak and then start to go back down way before you even reach the knock threshold. This is why a dyno is so important because you cant figure out what point your car is making its best torque at on the street.

      Arent engines intresting?
      93 MX-3
      BP, Wiseco Pistons, Pauter Rods, Haltech E6X, Turbonetics T3/T4 Ball Bearing, 3 inch turbo back exhaust, Bully Six puck clutch

      "Jesus, its raining out! I cant get traction in this!!!"

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        #18
        if you're knocking above 17 degrees advance, then your problem is probably no not spark advance. I haven't yet seen any reason to go beneath 20 degrees on properly tuned and engineered normally aspirated OR boosted cars. Even on 91 octane, you really shouldn't have to go beneath that.

        Most likely if you're experiencing knock at that little advance, you should be backing off the boost a little, or getting down and dirty with some cylinder head work.
        Ask me about engine management!

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          #19
          I think I mentioned earlier than an EVO runs stock 21-23 degrees advance at max boost and I think the boost is in the 20psi range.

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            #20
            Just changed my advance to 14 from 10. It makes a big difference ( at least in my car) No more hesitation in the lower rpm range like it was.
            Mx3 RS,BP-turbo
            http://www.cardomain.com/ride/2628805

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              #21
              14° is wonderful isn't it
              ---Has ClubProtege helped you in someway? show your support by Contributing--- Click Here---

              1992- project FE3..... 313 WHP @ 9.3psi




              I pet my dash when I get into the car..."good car"
              he actually has a mazda tree, parts grow on it

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                #22
                I might have to back it down. It will detonates when engine is cold. It only knocks once but its enough for me to back it down to 12. So Ill see what that feels like. Ill never run at 10 again, runs like a turd at 10.
                Mx3 RS,BP-turbo
                http://www.cardomain.com/ride/2628805

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                  #23
                  what cams do you have?
                  ---Has ClubProtege helped you in someway? show your support by Contributing--- Click Here---

                  1992- project FE3..... 313 WHP @ 9.3psi




                  I pet my dash when I get into the car..."good car"
                  he actually has a mazda tree, parts grow on it

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                    #24
                    I have the turbo cams from the BPT
                    Mx3 RS,BP-turbo
                    http://www.cardomain.com/ride/2628805

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