Announcement

Collapse
No announcement yet.

Holset H1C with 9cm housing?

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

    #16
    What have you gapped your plugs to? That's the most likely issue if it's missing in boost. My stock (single) fuel pump was at its limits running ~15psi or so with my M42, when I replaced it I had to completely retune in boost because my pulsewidths were artificially large thanks to dropping fuel pressure.

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

    Comment


      #17
      Originally posted by varg View Post
      What have you gapped your plugs to? That's the most likely issue if it's missing in boost. My stock (single) fuel pump was at its limits running ~15psi or so with my M42, when I replaced it I had to completely retune in boost because my pulsewidths were artificially large thanks to dropping fuel pressure.
      They are completely stock plugs gapped to stock oem setting (forget what that is).

      Plan was to get the car running and tuned at low boost (6-7 psi) then throw the colder ones in but I'm up to 10-11 psi. Only happens in higher rpms and at full boost and isn't like a harsh jutter is just a sputtering misfire so hoping and thinking that the colder plugs will fix that. Also hoping to not have to go wasted spark right now, could be an issue with the oem single coil set up.

      Will be swapping them out this week and doing more driving, my tuner guy is away again for 10 days so won't be able to data log or tune much without him here.
      2016 F-150
      1987 Royalblau 325es B25 turbocharged

      Build thread here: http://www.r3vlimited.com/board/showthread.php?t=405594

      Comment


        #18
        The stock gap is too large for boost, it will cause a miss and rich AFRs will make it worse. Reduce the gap to 0.022"/0.56mm and it will probably fix the problem. BTDT.

        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
          The stock gap is too large for boost, it will cause a miss and rich AFRs will make it worse. Reduce the gap to 0.022"/0.56mm and it will probably fix the problem. BTDT.
          Gapped one step colder plugs and installed them tonight. Ran at 11 psi all night with no issues, so much fun and seems to run excellent. Thanks man!
          2016 F-150
          1987 Royalblau 325es B25 turbocharged

          Build thread here: http://www.r3vlimited.com/board/showthread.php?t=405594

          Comment


            #20
            Originally posted by Dgerry View Post
            Hello all,

            A 9cm2 housing equates to a .65 A/R ratio, a .70 A/R converted to CM2 would be (roughly) a 9.5 CM2. My feeling is that no place other than a dyno would you notice the difference of 0.05 A/R ratio on the same turbo. So, if/when you did get your new housing that you ordered, again it would be a good choice for the street and depending on the compressor wheel that you have you should be able to turn it up as well. Currently I have a .63 A/R Garrett turbine housing on my 2.7 stroker running 12 psi at 3300rpm I have full boost. My comressor wheel is a custom Billet T04E 50 trim (you probably have a larger wheel than I do), at the 12 psi I am getting just over 300whp. Just giving you that info for a comparison once you get everything going. Hope this helps. Thanks,

            Dgerry
            Hey Dgerry how did you do that A/R to cm^2 conversion? I am curious because people generally tell m20 guys to avoid mitshibish turbos for being too small, but a mitsu evo turbo has a nozzle area of 10.5 cm^2 or so... 9.5 cm2 number seems too small.

            Comment


              #21
              Originally posted by grifle View Post
              Hey Dgerry how did you do that A/R to cm^2 conversion? I am curious because people generally tell m20 guys to avoid mitshibish turbos for being too small, but a mitsu evo turbo has a nozzle area of 10.5 cm^2 or so... 9.5 cm2 number seems too small.
              a while ago i got this table from other forum and i saved for me. i hope it help you.

              6 cm2 = 0.41 A/R
              7 cm2 = 0.49 A/R
              8 cm2 = 0.57 A/R
              9 cm2 = 0.65 A/R
              10 cm2 = 0.73 A/R
              11 cm2 = 0.81 A/R
              12 cm2 = 0.89 A/R
              14 cm2 = 0.97 A/R
              15 cm2 = 1.05 A/R
              16 cm2 = 1.13 A/R
              17 cm2 = 1.29 A/R
              19 cm2 = 1.37 A/R

              Comment


                #22
                ^^ Nice! That's helpful.
                2016 F-150
                1987 Royalblau 325es B25 turbocharged

                Build thread here: http://www.r3vlimited.com/board/showthread.php?t=405594

                Comment


                  #23
                  I'm running a similar setup to OP, stock M20B25, WH1C with the 9cm housing.

                  the car makes boost down low which is nice. You can definitely build boost as low as 2200 rpm if you lug the motor along, otherwise 3000 rpm and WOT results in boost within a second. Boost hits really hard but around 5k rpm you can really feel the power level off and fade as it cant move enough exhaust.

                  i took my 89 325ix to the dragstrip and managed a 13.9 @ 105 with a baby soft launch since I didnt want to bust the front diff. 105 with a weight of about 3000 says its making 260hp. Not sure if thats wheel or crank equivalent though.

                  I'm currently looking for a replacement thats in the 12cm range but with a vband exit, not the stock funky wastegate version.
                  325IX Build Thread
                  RX7 Build Thread

                  Comment


                    #24
                    is this specific to the hx35 or is cm just cm like

                    a 16cm is the same even on a hx55.


                    Originally posted by matias9 View Post
                    a while ago i got this table from other forum and i saved for me. i hope it help you.

                    6 cm2 = 0.41 A/R
                    7 cm2 = 0.49 A/R
                    8 cm2 = 0.57 A/R
                    9 cm2 = 0.65 A/R
                    10 cm2 = 0.73 A/R
                    11 cm2 = 0.81 A/R
                    12 cm2 = 0.89 A/R
                    14 cm2 = 0.97 A/R
                    15 cm2 = 1.05 A/R
                    16 cm2 = 1.13 A/R
                    17 cm2 = 1.29 A/R
                    19 cm2 = 1.37 A/R

                    Comment


                      #25
                      It is specific to what brand and frame/model size you are comparing it to. So, for example, HX35/40 stuff yes, the cm2 crosses over. An HX35 and a HX55, no, you can't compare them as the HX55 has such a large turbine wheel. Just as a rule of thumb, if the turbine wheel exducer size is the same or pretty close, you can use the cm2 to A/R as a comparison. An example of this would be an HX35 and a GT35R. I am sure that this is confusing, but I don't really know a better way to explaining this.

                      Holset makes a 12cm2 non wastegated housing, part # 3524123H or 3524123, you might also be able to find an aftermarket source for this as well. Hope this helps, thanks.

                      Comment


                        #26
                        i see. hx35 and hx40 would not be the same either then because one is t3 and the other is t4.

                        Comment


                          #27
                          Well, actually it would be, again it is the turbine wheel exducer size that you would go off of and not the flange size of the turbo. When you are referring to T3 and T4 flange sizes, that does not change the turbine wheel size. And, to add to the confusion, there are actually HX40 turbos with T3 flanges. Flange sizes are determined by the application. There are also T25 turbos with T3 flanges, T3 turbos with T25 flanges, and T4 turbos with T3 flanges. For the most part in sizing a turbo the flange does't matter, unless you have a specific one on your header or manifold and you need one to fit that. There is a lot of stuff to keep up with on turbos, ebay, forums and turbo shops in general have tried to "simplify" it to flange size, compressor size etc.... The parts of the turbo that tell you how much HP you can make and it it is a good match for you application are the compessor wheel sizes, turbine wheel sizes and turbine housing size, everything else is trivial for most applications and won't make much of a difference in the grand scheme of things.

                          Comment

                          Working...
                          X