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Highest HP Stock bottom end m20

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    #16
    93 octane. Stock compression ratio.

    IG @turbovarg
    '91 318is, M20 turbo
    [CoTM: 4-18]
    '94 525iT slicktop, M50B30 + S362SX-E, 600WHP DD or bust
    - updated 1-26

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      #17
      Originally posted by varg View Post
      93 octane. Stock compression ratio.
      Well there is your answer. I can run much higher timing because of E85. usually 6-8* more then gas. I am probably little lower cr due to the 2.7/885 combo.
      - AXIS POWERS - 2JZ E30 Build
      Current Project - 87 325is 2JZ Swapped with M4 DCT

      Comment


        #18
        Yes, you mentioned that earlier in the thread. The reason I replied it's a good amount of advance is because you said "not as much you'd think." It was right in line with what I'd expect. The lower compression ratio 2.7/885 combo may require more advance to make power, but due to the poor interface of the piston and combustion chamber it may be simultaneously more prone to detonation due to poor quench.
        Last edited by varg; 11-28-2018, 04:03 PM.

        IG @turbovarg
        '91 318is, M20 turbo
        [CoTM: 4-18]
        '94 525iT slicktop, M50B30 + S362SX-E, 600WHP DD or bust
        - updated 1-26

        Comment


          #19
          Originally posted by varg View Post
          Yes, you mentioned that earlier in the thread. The reason I replied it's a good amount of advance is because you said "not as much you'd think." It was right in line with what I'd expect. The lower compression ratio 2.7/885 combo may require more advance to make power, but due to the poor interface of the piston and combustion chamber it may be simultaneously more prone to detonation due to poor quench.
          Right. Flame propagation is trash compared to the normal 2.5 setup. I used to run much higher timing, and didn't see any issues with it, and only recently dropped my timing down for drifting purposes to conserve. I have seen some m20 maps with a lot higher timing and made great power on a similar setup. I have also read some discussions about how with m20s you can almost not run enough timing, especially lower compression and shit quench. Haven't heard of it being more prone to detonation though?
          - AXIS POWERS - 2JZ E30 Build
          Current Project - 87 325is 2JZ Swapped with M4 DCT

          Comment


            #20
            With poor flame propagation you can reach the detonation limit of timing advance more quickly than you would with an equivalent engine that has the proper piston design to work with the head.

            IG @turbovarg
            '91 318is, M20 turbo
            [CoTM: 4-18]
            '94 525iT slicktop, M50B30 + S362SX-E, 600WHP DD or bust
            - updated 1-26

            Comment


              #21
              Originally posted by SLEEPYDUB View Post
              Ms2


              Have any dyno sheets at 550?


              Sent from my iPhone using Tapatalk

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                #22
                Originally posted by cream_e30 View Post
                Have any dyno sheets at 550?


                Sent from my iPhone using Tapatalk
                I don't. The 550 estimate was based off of fuel injector calculations. I can tell you that at 30psi it felt just as fast as my 550whp 2JZ E30 at at 22psi. Again, that was just an estimate. I will have some true figures soon enough, but it will be on a built 2.9
                - AXIS POWERS - 2JZ E30 Build
                Current Project - 87 325is 2JZ Swapped with M4 DCT

                Comment


                  #23
                  Originally posted by varg View Post
                  With poor flame propagation you can reach the detonation limit of timing advance more quickly than you would with an equivalent engine that has the proper piston design to work with the head.
                  What would you consider too much advance on the 2.7/885 combo?
                  Say, 1 bar and E85?
                  - AXIS POWERS - 2JZ E30 Build
                  Current Project - 87 325is 2JZ Swapped with M4 DCT

                  Comment


                    #24
                    Naturally aspirated, MBT is about 27°.
                    john@m20guru.com
                    Links:
                    Transaction feedback: Here, here and here. Thanks :D

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                      #25
                      Originally posted by ForcedFirebird View Post
                      Naturally aspirated, MBT is about 27°.
                      Thats about what I run at 100kpa, 27* at 5500rpm and goes up to 28 by redline. In boost, at 1 bar, I run about 18* at 3500 and slowly tapers up to 20* by redline.

                      For a boosted engine, E85, 2.7 bottom/885 head, what would you consider safe timing? What would you consider too much timing? Where would MBT sit at under boost?
                      - AXIS POWERS - 2JZ E30 Build
                      Current Project - 87 325is 2JZ Swapped with M4 DCT

                      Comment


                        #26
                        Originally posted by cream_e30 View Post



                        Have any dyno sheets at 550?


                        Sent from my iPhone using Tapatalk
                        I did dyno my stock 2.7 bottom with 885 head before I pulled it out to go 2JZ + DCT swap. Head used a 280/274 bimmerheads cam.

                        21psi on E85, made 522whp


                        Sent from my SM-N986U using Tapatalk

                        Attached Files
                        - AXIS POWERS - 2JZ E30 Build
                        Current Project - 87 325is 2JZ Swapped with M4 DCT

                        Comment


                          #27
                          Big power. That was with the 6266? Where was full boost, 5,000rpm?

                          IG @turbovarg
                          '91 318is, M20 turbo
                          [CoTM: 4-18]
                          '94 525iT slicktop, M50B30 + S362SX-E, 600WHP DD or bust
                          - updated 1-26

                          Comment


                            #28
                            Great numbers .. I’d like to also know where the powerband was
                            sigpic

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                              #29
                              Originally posted by varg View Post
                              Big power. That was with the 6266? Where was full boost, 5,000rpm?
                              Sorry for late reply, I rarely get on here. I just finished up my 2JZ with M4 DCT swap and am about to post a build thread on it.
                              This was a 0.81ar T4 6266. Full boost on the log was around 4500rpm.
                              - AXIS POWERS - 2JZ E30 Build
                              Current Project - 87 325is 2JZ Swapped with M4 DCT

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