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m20 maf conversion?

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    #16
    Originally posted by nando View Post
    the only dyno of a MAF conversion I've ever seen is Miller's own which claims a 20whp increase. I'm still skeptical.

    as far as what the restriction is (re: jlevie), yeah it's the head.. and intake manifold, and throttle body, and AFM, and airbox, and exhaust, and cam, etc. etc. The engine was put together with everything sized "just right" for everything else. you can't really upgrade one thing and expect a huge increase with everything else left stock.
    The ONLY way to do that would be if he is doing what they did (maybe still do?) to the Ricer crowd.

    "This header makes 15whp on your Civic over stock!!!!!"

    What they didn't tell you was that it was a built motor with high comp pistons, headwork, cams etc, so yes in that case the stock header is the restriction, but on a stock motor? Not much to be gained.
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      #17
      Originally posted by Curt Hayes View Post
      Not sure you could get a MAF to function with a stock chip. I read a write-up by a guy that made his own conversion, and he said the issue is two-fold: the MAF puts out a different range of signal for the same flow, and he found that there are resonances that the MAF will measure that the AFM will filter out due to the mass of the door limiting the response rate. The resonance causes the MAF to measure the air flowing both directions, leading to rich running because the DME thinks there is more air going in than really is.
      So, you might be able to find a MAF with some sort of conversion chip onboard, but the DME will get confused by the double-measurement of the air. This guy's conclusion was that you need a chip with a special map to take care of both of these problems.
      Caveat: I don't know the guy, and can't find the write-up, so I can't vouch for the science involved. From what I can remember, it looked pretty solid, though.
      the real reason it can't be a direct plug in without software changes is a MAF measures air mass, while an AFM measures pressure and calculates mass based on other assumptions and factors.
      Build thread

      Bimmerlabs

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        #18
        Just out of curiosity: Isn't the output from the AFM a resistance value and the output from the MAF a voltage value? Not that it matters for anything, im not going to do a MAF conversion. Instead I will show all the suckers how its done and route my intake straight to the A/C vents, that way I can have 40F-50F air going into the engine even in the dead of summer (sarcasm meter asplode)

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          #19
          they both output voltage but the relationship of the voltage curve to air flow is completely different.
          Build thread

          Bimmerlabs

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            #20
            Originally posted by nando View Post
            the only dyno of a MAF conversion I've ever seen is Miller's own which claims a 20whp increase. I'm still skeptical.

            as far as what the restriction is (re: jlevie), yeah it's the head.. and intake manifold, and throttle body, and AFM, and airbox, and exhaust, and cam, etc. etc. The engine was put together with everything sized "just right" for everything else. you can't really upgrade one thing and expect a huge increase with everything else left stock.
            The castros had a graph for their airbox/maf conversion as well. I was the main shit talker in that thread since they were also claiming like 20whp gains. People even said the cars felt like M50 swap cars.

            Either it's a massive conspiracy or maf conversions really do net you some noticeable power gains.

            Matt
            Matt

            Originally posted by slammin.e28guy
            I pack my CD player with asbestos. Those mother fuckers pay dearly for stealing my shit.
            Originally posted by kronus
            try whacking parts of the motor with a wrench while yelling "YOU WANT SUMMA DIS? HUH?"
            Originally posted by chadthestampede
            This is like a reverse build thread; it starts out nice and gets shitty.

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              #21
              Originally posted by E30Nova View Post
              Either it's a massive conspiracy or maf conversions really do net you some noticeable power gains.

              Matt
              Could be the throttle-response thing referred to earlier. "Snappy" is going to feel like "more".
              S52-Powered 1987
              sigpic

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                #22
                This is true.

                I know my car has massive lag when blipping the throttle, either due to the afm or a worn throttle cable.

                Even my friends that have test drove my car have been like "wtf is wrong with your shit?!" :(

                Matt
                Matt

                Originally posted by slammin.e28guy
                I pack my CD player with asbestos. Those mother fuckers pay dearly for stealing my shit.
                Originally posted by kronus
                try whacking parts of the motor with a wrench while yelling "YOU WANT SUMMA DIS? HUH?"
                Originally posted by chadthestampede
                This is like a reverse build thread; it starts out nice and gets shitty.

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                  #23
                  Originally posted by E30Nova View Post
                  The castros had a graph for their airbox/maf conversion as well. I was the main shit talker in that thread since they were also claiming like 20whp gains. People even said the cars felt like M50 swap cars.

                  Either it's a massive conspiracy or maf conversions really do net you some noticeable power gains.

                  Matt
                  I'm not saying there is no gain, I'm skeptical of a 20whp power increase.
                  Build thread

                  Bimmerlabs

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                    #24
                    As am I, but I figure if it helps with the throttle response and maybe gets me a bit more mpg along with a slight power boost, it's worth it.

                    Matt
                    Matt

                    Originally posted by slammin.e28guy
                    I pack my CD player with asbestos. Those mother fuckers pay dearly for stealing my shit.
                    Originally posted by kronus
                    try whacking parts of the motor with a wrench while yelling "YOU WANT SUMMA DIS? HUH?"
                    Originally posted by chadthestampede
                    This is like a reverse build thread; it starts out nice and gets shitty.

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                      #25
                      Sure does sound enticing: nice idle, real throttle response, plus some power. Hell, even no power gain, if you got the other two, would sound nice.
                      S52-Powered 1987
                      sigpic

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                        #26
                        I think it's priced pretty agressive as well. I don't think it's an unreasonable mod, I just think the performance gains are perhaps a bit overstated. Or at least I haven't seen any customers independently dyno theirs before/after..
                        Build thread

                        Bimmerlabs

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                          #27
                          Has anybody done this AFM conversion with a 91 325is m20 using 272 cam / bavauto chip / ram air box w/k&n filter / shorty highflow cat running 2 1/2 inch exhaust (single in single out)/ 4:10 lsd OH ........................with an automatic but yet with results & hp#'s ? ;) And dont HATE on the auto (daily driver)
                          Last edited by QUKBMER; 07-15-2010, 01:01 PM.
                          Your signature picture has been removed since it contained the Photobucket "upgrade your account" image.

                          garage queen 91 bmw 325is / 1972 Chevy El Camino 355 sbc 450hp

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                            #28
                            I've got a 2.5 with head work, cam and headers. Planning on buying the MAF kit within a month. I will let you guys know how it goes.
                            BimmerHeads
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                              #29
                              Sweetness.Six years deep, no where near a swap yet..but hell still curisoue to see the digits.

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                                #30
                                I love the MAF conversion, it frees up about 2" of room in the intake tract, sounds amazing, and gives the car a much more responsive/modern car feel.


                                7speedshop.com

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