Announcement

Collapse
No announcement yet.

ForcedFirebird's m20 dyno thread.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    #46
    Originally posted by jeffnhiscars View Post
    Could the extruded intake have made that much difference and if I may ask what that costs ?

    I have a feeling the diff is causing parasitic loss. Going to pull it out tomorrow anc check it out.


    Originally posted by digger View Post
    It's amazing that both graphs are basically identical upto 5000rpm.

    So the first has
    - standalone ecu
    - header
    - exrtrude hone
    - bbtb and fine style inlet
    - tighter squish clearance

    But the second has a IE 272, is it regrind or Schrick knock off ?

    New cam.





    Two other differences are the first one has 3.73 final drive, second has 4.10 with oil pressure relief blocked (~80ish psi oil pressure max), and first had 10w40 conventional, second had 10w60 (~65 max oil pressure) - but don't believe the oil made the difference as they both were hot enough.
    john@m20guru.com
    Links:
    Transaction feedback: Here, here and here. Thanks :D

    Comment


      #47
      my guess is the differences are mostly breathing mods
      89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

      new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

      Comment


        #48
        looks like that cam isn't doing shit

        Comment


          #49
          Originally posted by digger View Post
          my guess is the differences are mostly breathing mods
          Originally posted by LowR3V'in View Post
          looks like that cam isn't doing shit

          I just pushed the car into a spot to pull the diff, and something is dragging pretty hard. It's very easy to push backwards, but going forward is 2x the effort.



          As far as the 2 engines and the cam, one added lift/duration for more flow with nothing upstream, and the stock cam car increased flow before/after combustion. I have dyno tested headers similar to these and they are worth 5-8whp/tq - but we are missing closer to 10.
          Last edited by ForcedFirebird; 02-01-2019, 11:58 AM.
          john@m20guru.com
          Links:
          Transaction feedback: Here, here and here. Thanks :D

          Comment


            #50
            How is an "extrude hone" done in a curving intake runner like that? I'm trying to picture the hardware that does this. Is it just smoothing, or removing metal to enlarge the diameter?

            Thanks -

            Comment


              #51
              Originally posted by LateFan View Post
              How is an "extrude hone" done in a curving intake runner like that? I'm trying to picture the hardware that does this. Is it just smoothing, or removing metal to enlarge the diameter?

              Thanks -



              https://www.youtube.com/watch?v=2QBc59YZYxA
              john@m20guru.com
              Links:
              Transaction feedback: Here, here and here. Thanks :D

              Comment


                #52
                How much of a difference do you think it is with and without that 2mm off the deck? Im guessing that bumps the CR from ~8.5:1 to ~9.5:1
                Simon
                Current Car:
                -2003 Mini Cooper
                -1968 Datsun Roadster 2000
                Previous Car Count : 23 ... and climbing...

                Make R3V Great Again -2020

                Comment


                  #53
                  Originally posted by 2mAn View Post
                  How much of a difference do you think it is with and without that 2mm off the deck? Im guessing that bumps the CR from ~8.5:1 to ~9.5:1

                  The added stroke is what bumps the compression - swept volume. The 2mm off the deck is because the crank is 6mm more (3mm up, 3mm down strokes), but the rods are 5mm shorter than b25. Taking the 2mm puts the pistons back up close to the head. If you didn't shave them, you would have an extremely large quench/squish (distance between the head and pistons at TDC).
                  john@m20guru.com
                  Links:
                  Transaction feedback: Here, here and here. Thanks :D

                  Comment


                    #54
                    on that extrude vid u linked
                    i don't really know what those numbers really mean but just notice
                    the very even distribution of the runners.
                    Seems like a good thing but based on the number differences before/after
                    is it worth the money vs power you are seeing? Would it matter as much on an FI engine?
                    Last edited by LowR3V'in; 02-01-2019, 05:29 PM.

                    Comment


                      #55
                      50% more flow from making it a poofteenth bigger? yeah righto....they are also doing it wrong as you need a piece at the end to stop the edges of the exit being rounded over and screwing up the matching of the interface to the head

                      i had a manifold treated with a similar process (but not EH) the flow numbers improved and so did the balance but it made noticeably less power by 9whp...i got a spare one treated so it wasn't the same manifold. if it made the same power then i could say maybe th operator didn't pump enough shit down its throat, but to go backward maybe the polish isn't so good? the AFR were identical within 0.2AFR the entire run with no tune changes so probably moving the same amount of air but not making power from it so combustion efficiency and BSFC down the toilet. after that i got the MM pulse tune manifold and did a cam swap
                      Last edited by digger; 02-01-2019, 06:38 PM.
                      89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

                      new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

                      Comment


                        #56
                        Originally posted by LowR3V'in View Post
                        Would it matter as much on an FI engine?

                        That's a whole 'nother conversation. When you pressurize a system, you are no longer relying on the atmosphere to "allow" the air charge to enter an engine, you are "forcing" it in.



                        I actually prefer to make an engine as strong as I can BEFORE adding above atmo. The old saying "lower the compression, add more boost" is moot in modern days - when generally, if you have a strong engine and add boost, the strong engine will always out perform a low compression over all - just keep in mind when you have a lot of added static compression and add boost, your tuning window gets extremely small - low compression/high boost engines are very forgiving on timing and fuel delivery, and fuel type becomes critical on high comp.

                        I am not afraid to boost 10:1 engines. The low compression gig is a fallacy IMO.


                        I like to say N/A all the way! Anyone can throw a big turbo on a car, not many people can pull big numbers from an N/A engine.
                        john@m20guru.com
                        Links:
                        Transaction feedback: Here, here and here. Thanks :D

                        Comment


                          #57
                          Originally posted by ForcedFirebird View Post
                          The added stroke is what bumps the compression - swept volume. The 2mm off the deck is because the crank is 6mm more (3mm up, 3mm down strokes), but the rods are 5mm shorter than b25. Taking the 2mm puts the pistons back up close to the head. If you didn't shave them, you would have an extremely large quench/squish (distance between the head and pistons at TDC).
                          Oh yea thats right.

                          I was thinking about my SuperETA block...

                          Im really curious what mine will make with the package I am expecting in a week ;)
                          Simon
                          Current Car:
                          -2003 Mini Cooper
                          -1968 Datsun Roadster 2000
                          Previous Car Count : 23 ... and climbing...

                          Make R3V Great Again -2020

                          Comment


                            #58
                            Originally posted by 2mAn View Post
                            Oh yea thats right.

                            I was thinking about my SuperETA block...

                            Im really curious what mine will make with the package I am expecting in a week ;)
                            What will your setup be?

                            Comment


                              #59
                              Originally posted by ForcedFirebird View Post
                              Honestly I have not done much with the adjustable gears on the dyno.


                              Here's the graphs from Sat.



                              81mm crank, 130mm rods, b25 pistons, .080" (2.03mm) off the deck, stock cam (and cam gear), in house rebuilt head, .035 quench, bored throttle body, extrude manifold, eBay headers, single 2.5" exhaust through 2 mufflers. MS1 with a smooth elbow pipe, cone filter.


                              [ATTACH]125591[/ATTACH]


                              81mm crank, 130mm rods, b25 pistons, .080" (2.03mm) off the deck, IE 272 cam (stock cam gear), in house rebuilt head, .050" quench, stock intake/TB, stock exhaust manifolds, single 2.5" exhaust with a single resonator. Stock ECU re-mapped at the dyno.


                              I believe this car "should" have made more power, was actually a little disappointed. Later after watching a video sent by a friend, I can hear a lot of diff noise that was impossible for me to hear in the car while tuning (one car bay with a dyno in it). Doubt we will bring it back to the dyno, just rebuild the diff and send it racing.



                              [ATTACH]125592[/ATTACH]
                              Nice Dyno #'s! I recently purchased a set of 12:1 85mm Vac 885 head pistons for a 89.6 and 135mm stroker build but the m54 block I had in mind was thrown away before I got to it.

                              So I found a set of 138mm rods that I'll use with a 81mm eta crank to build my 2.7i. I'mm just have to deck the block 1mm and put a thicker 0.100" gasket to lower compression to 11.5:1.

                              I'll be using my stock 885 head and 284/272 schrick which made my stock b25 anemic down low.

                              Looking forward to end results.

                              Comment


                                #60
                                Why not use 84mm stroke as that works almost spot on or get another 89.6 crank they aren't expensive in the grand scheme of the overall build process
                                89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

                                new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

                                Comment

                                Working...
                                X