Announcement

Collapse
No announcement yet.

DIY - M20 throttle body vacuum fittings

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

    #16
    Originally posted by modernist View Post
    Elbow
    Hose barb

    I bought the set screw at my local hardware store. The only thing that's really crucial is the 7/16-20 thread going into the throttle body itself -- what you choose to screw into the holes is totally up to you!
    Link for the elbow doesn't appear to work anymore.
    1991 325i - "Scambles" The Daily Driven lightly modded.
    1988 Mazda RX-7 TII "Mako" The Free Dorito
    bacon by Jared Laabs, on Flickr

    Comment


      #17
      New link

      Link updated elsewhere as well

      1986 327i
      transaction feedback
      DIY thing
      meh

      Comment


        #18
        I would like to do this on my M20, however I have an '87 325is that was originally automatic so it has the two hoses and a connection to the intake boot.

        I like the simplicity of this and realized I can order a later model intake boot which doesn't have the port so I'm good there.

        I have two questions:

        First, what is that valve you have in the middle of your vacuum hose? The only valve I can find on RealOEM is the complex little check valve that is used with the two hose design.

        Second, why is that little brass pipe at the back of your throttle body plugged? Mine has a line leading to a valve/plug (I believe its the Evap Purge Valve) which then leads to the charcoal canister. Are you just not running a charcoal canister so you deleted the whole system?

        Thanks


        --Roundie Revival 2.0 - 1973 BMW 2002 Build Thread--
        --Golden Boy E30 Build Thread-- (sold)

        Comment


          #19
          Ok since I posted my last comment I did a bit of research and think I have this figured out. If someone with experience could confirm this that would awesome.

          The late model single vacuum hose design doesn't show up on RealOEM, but I found another thread where a guy posted this picture and said this:

          "Old hose on the left has what looks like an in-line check valve with OEM clamps. The fitting at the booster is just an elbow.

          The new part from Blunt is a check valve in the 90 degree fitting, plus new grommet."



          Apparently this 90 degree check valve is now superceded according to a few sites but I found that ECS carries it for $5



          What I want to confirm is that if I bought this 90 degree check valve and put it in the place of the elbow fitting on the brake booster, I could then run a straight vacuum line from the brake booster to the throttle body correct?

          Another option that I found is by using an E21 vacuum check valve (part number 34331151533A), which is only $8, also available on ECS. With this you would run the original elbow fitting on the brake booster and then run the E21 check valve in line to the throttle body. It seems like these two options achieve the exact same results.



          Anyone know why the 90 degree check valve is superceded? Did they fail a lot or something? Or did they just realize that selling the complex 4 way check valve would be much more profitable?

          I just want to simplify my setup as much as possible. Any input would be appreciated. Thanks


          --Roundie Revival 2.0 - 1973 BMW 2002 Build Thread--
          --Golden Boy E30 Build Thread-- (sold)

          Comment


            #20
            Who knows but my eta had the single like the pic you posted. Then when I converted to 325i motor I got the double check valve.

            Comment


              #21
              Hey sorry for the late reply. The valve is the original check valve from when this car was from an eta. 90 degree or straight doesn't matter as long as it's put in the right way around. The brass pipe on the throttle body is plugged because I vented the charcoal cylinder directly to the air. My evap valve was faulty and I couldn't afford a new one. Hope this helps!

              1986 327i
              transaction feedback
              DIY thing
              meh

              Comment


                #22
                This is exactly what I needed to see because my 90 525i throttle body has no part number for the elbow fitting and I cannot find the part ANYWHERE. Thank you so much for this. I made an account just to thank you and I am extremely new to this whole forum thing.

                Comment


                  #23
                  For anyone doing this mod, it is also helpful to know what to purchase to simplify your vacuum routing as well going to the brake booster. What you'll need for that (via chubby chowder's thread):

                  Intake boot without vacuum port (part number 13711726325):


                  90 degree check valve (part number 34331156703):


                  Brake Booster grommit for check valve (34331158929):


                  And then just one hose going from the 90* check valve in the booster to the throttle body barb.

                  Total costs (with shipping because it's a killer on all of these fittings):

                  -Intake Elbow, check valve, and grommit from ECS: $39.02
                  -7/16-20 tap and 25/64 drill bit (amazon): $16.36
                  -Brass Hose Barb: $8.61
                  -Socket Set Screw Cup Point 304 SS - 7/16"-20 x 3/4" (Albany County Fasteners): $8.34
                  -NPT Elbow (BuyFittingsOnline): $23.61

                  Total: $95.94
                  1990 Brilliantrot 325iS Build Thread
                  1989 Zinnoberrot M3 Build Thread

                  Comment


                    #24
                    Originally posted by AWDBOB View Post
                    For anyone doing this mod, it is also helpful to know what to purchase to simplify your vacuum routing as well going to the brake booster. What you'll need for that (via chubby chowder's thread):

                    Intake boot without vacuum port (part number 13711726325):


                    90 degree check valve (part number 34331156703):


                    Brake Booster grommit for check valve (34331158929):


                    And then just one hose going from the 90* check valve in the booster to the throttle body barb.

                    Total costs (with shipping because it's a killer on all of these fittings):

                    -Intake Elbow, check valve, and grommit from ECS: $39.02
                    -7/16-20 tap and 25/64 drill bit (amazon): $16.36
                    -Brass Hose Barb: $8.61
                    -Socket Set Screw Cup Point 304 SS - 7/16"-20 x 3/4" (Albany County Fasteners): $8.34
                    -NPT Elbow (BuyFittingsOnline): $23.61

                    Total: $95.94
                    If your goal is to just simplify the booster lines...

                    I just used a silicone plug on the extra TB elbow, then bought a generic check valve to put in-line. I coupled that with one of those silicone vacuum line kits for the lines. With the new intake boot. This is what mine looks like.



                    Pretty sure I had the check valve the wrong way in this pic, lol. You could couple it with the tapped holes in the TB also, I would presume, to get a better seal at the TB. Obviously my method is much more half assed, but it got the job done.
                    '86 Burgundrot 325 2.8 stroker.

                    Build thread

                    Other cars:
                    2000 Porsche Boxster
                    2006 Subaru Outback XT 5MT
                    1972 Porsche 914

                    Comment


                      #25
                      Does anyone have a similar repair for the ICV connection on the other side of throttle?

                      Comment


                        #26
                        Originally posted by ncjunglist View Post
                        Does anyone have a similar repair for the ICV connection on the other side of throttle?


                        wake up!


                        Sent from my iPhone using Tapatalk Pro

                        Comment


                          #27
                          Nice write up! I really like the idea of threading the holes. Its definitely a sound way to make sure they don't wiggle loose.



                          My idea for improving the reliability of the vacuum hoses would be to solder the aluminum elbows directly to the throttle body. It could be the cheapest way to do ensure they don't wiggle loose. You could also fill the unused elbow with solder to act as a plug. Just my idea. I'll post pics if I go this route. I really like the silicone vacuum hoses that were posted by betz. I will definitely be going that route.
                          - 1982 528e e28 m20b27, e2i, schrick 272

                          Comment


                            #28
                            That's not going to be easy to solder, the throttle body is a pretty big mass of aluminum, you're going to have to remove all the decades of oxidation on it too.

                            Comment


                              #29
                              Sorry to add to a very old thread but just thought I would add for anyone who might not be able to figure out what to use for the ICV side, I bought a 21/32 drill bit, m18x1.5 tap and m18x1.5 male to 19an male fittings with a female 10an to whatever barb size you desire, I picked 5/8 as the hose ID was about .68in I believe.

                              Comment


                                #30
                                I'll just leave this here:

                                Your resource to do-it-yourself and interesting bmw and e30 stuff: www.rtsauto.com

                                Your resource to tools and tips: www.rtstools.com

                                Comment

                                Working...
                                X