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EFI Intake plenum volume

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  • EFI Intake plenum volume

    OK before you look and get wigged out, this should show you more than plenum volume to think about.





    http://www.youtube.com/watch?v=Ujrdq...eature=related
    2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
    First to run in the .90s .80s and .70's in SBN/A
    2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
    2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

  • #2

    Re: EFI Intake plenum volume

    Way cool!
    Escaped on a technicality.

    Comment


    • #3

      Re: EFI Intake plenum volume

      haha.
      could pretend individual throttle bodies too I guess.

      what measurement is getting lost taking the cover off?

      seems to be none.

      I run back to 20 inches Hg of atomizer now..
      Previously boxer3main
      the death rate and fairy tales cannot kill the nature left behind.

      Comment


      • #4

        Re: EFI Intake plenum volume

        Plenum volume and the pressure wave VE should be down.

        See the top moving around even with his hand on it thats the pressure waves hitting it.

        Also see the reversion coming up the runners

        I would change the plenum the rear right has to have issues being that close to the radius of the port
        2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
        First to run in the .90s .80s and .70's in SBN/A
        2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
        2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

        Comment


        • #5

          Re: EFI Intake plenum volume

          I would call that a verrry slow throttle response...
          www.BigBlockMopar.com

          Comment


          • #6

            Re: EFI Intake plenum volume

            LOL loads will do that. The long pulls on a dyno I just turn my head and cross my fingers.
            2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
            First to run in the .90s .80s and .70's in SBN/A
            2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
            2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

            Comment


            • #7

              Re: EFI Intake plenum volume

              Too bad there's no with / without dyno graphs in the video.

              Comment


              • #8

                Re: EFI Intake plenum volume

                LOL loads will do that. The long pulls on a dyno I just turn my head and cross my fingers.
                If you think that's bad, you should observe some of the steady-state testing that goes on. "Please hold my SuperStock Hemi at 9500rpm long enough to get a snapshot of combustion pressure" the cringe factor is huge.
                www.realtuners.com - catch the RealTuners Radio Podcast on Youtube, Facebook, iTunes, and anywhere else podcasts are distributed!

                Comment


                • #9

                  Re: EFI Intake plenum volume

                  I was thinking just that as we where talking Scott, the Wheeeewww Factor of ok thats over lets not do it again.

                  I want a dyno! To abuse my junk on, no car needed
                  2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
                  First to run in the .90s .80s and .70's in SBN/A
                  2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
                  2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

                  Comment


                  • #10

                    Re: EFI Intake plenum volume

                    Too bad there's no with / without dyno graphs in the video.
                    I agree but would think it would have to be lower, with the top off and Slower to get there too. I look at that as much as anything.
                    2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
                    First to run in the .90s .80s and .70's in SBN/A
                    2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
                    2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

                    Comment


                    • #11

                      Re: EFI Intake plenum volume

                      That's a big vacuum leak right there!

                      HA. I'm guessing that all started with a couple guys arguing about plenum volume.
                      There's always something new to learn.

                      Comment


                      • #12

                        Re: EFI Intake plenum volume

                        Suffice it to say, the throttle body is not the restriction to that intake.
                        Why think when you can be doing something fruitful?

                        Comment


                        • #13

                          Re: EFI Intake plenum volume

                          I agree but would think it would have to be lower, with the top off and Slower to get there too. I look at that as much as anything.
                          Thats interesting; I would love to see a comparison too.

                          We did lots of work with airbox volume when I was building motorcycles (Same as plenum volume in car language).
                          Motorcycles have butterflies at each intake runner (even with carbs), and cars typically have them before the air plenum. Probably for simplicity sake, but at WOT it all the same.

                          Changing Airbox volume and intake runner length were one of the most interesting experiments I have ever done on a dyno.

                          More airbox/plenum volume from what I saw on my projects was always better through the entire rpm range, but the biggest gains were in the midrange. The trick was finding more volume in the confined space of a motorcycle chassis.

                          You called it pressure waves and reversions; we called it intake resonance, and found that certain frequencies could actually disrupt power significantly at a certain rpm range.
                          Last edited by mike343sharpstick; April 4th, 2012, 10:01 AM.

                          Comment


                          • #14

                            Re: EFI Intake plenum volume

                            Yeah, I have always been told, keep stacking spacers on the Plenum till the power drops on the dyno, then at the track keep taking them off till it slows down.

                            Mine has a Reversion "Hole" at about 2500 to 2800 then its back on like a light switch. In that range it mixes up cylinders some not a true miss just sounds weird and power drops off. I just use the converter to drive past it.
                            2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
                            First to run in the .90s .80s and .70's in SBN/A
                            2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
                            2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!

                            Comment


                            • #15

                              Re: EFI Intake plenum volume

                              Hmmm, reversion hole. I have a similar deal at a similar RPM in street driving. Talking with Scott there may be an interplay between the interpolation function as it edges to next pair of bins on the VE table along with some errant TPS based Accel enrichment. I get a fat miss across some cylinders for a few seconds and I see the the AFR guages dip into the 11's. Much more work to do but I'm generally pleased with the real world drivability given the 4400+ cfm of the dual TB's.

                              No doubt the high stall converter masks a lot of what would otherwise be annoying stuff at low rpm load with the stick.

                              We are truly in a wonderful age being able to drive around with these kinds of HP/cu.in. NA and live to tell about it.
                              Drag Week 2006 & 2012 - Winner Street Race Big Block Naturally Aspirated - R/U 2007 Broke DW '05 and Drag Weekend '15 Coincidence?

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