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    Originally posted by wazzu70 View Post
    This is true of atmo cams. If you want it to be perfect it needs to be custom ground for your specific application. Even then, you can buy sport, rally, ect cams.

    The VAC turbo grinds are a great all around grind that will work with most setups. Like all turbo cams you need a free flowing exhaust to really make them shine (no log mani, no rediculiously small turbine housing). The grinds aren't 100% perfect for all applications but its still leauges ahead of using stock garbage :)
    I agree, but it seems like it's not quite as simple as choosing N/A cams. It's more or less making a cam for the motor as apposed to building a motor around a cam.

    Also another really good article to read...




    Does anyone have a cam card for the VAC turbo cams? Seems like that would be some good info for the tread since it's not stated on the site. Also MFDOOM when you contacted VAC were they suggesting custom cams or just giving you the option?

    And if your wondering why I am bothering to post here, my next e30 IS going to be a turbo'ed m10 or m42... Was looking at buying buttchugz 84 318i awhile back, but slacked on it and it sold.
    sigpic

    A man chooses, a slave obeys... Would you kindly?

    Comment


      Go to www.catcams.be and you can find the specs.

      Choosing a cam for FI really isn't any different than atmo. Atmo cams also work great for FI if you have an efficient hotside. Turbo cams are usually just a hot intake lobe paired with a mild exhaust lobe and an advanced intake centerline to reduce overlap.

      Obviously there are variations that could be better, but the gains are relatively minor compared to the jump from factory cams to a turbo specific grind.

      A lot of the turbo cam info out there is from the early 80s when turbos were more exhaust restrictions than power adders. The old stock cams are best for boost assums you have a log manifold and a restrictive turbo with tons of backpressure.

      Some turbo cam info on BF.c http://forums.bimmerforums.com/forum...ht=Turbo%20cam
      Last edited by wazzu70; 10-16-2013, 07:18 PM.
      -Nick

      M42 on VEMS

      Comment


        Originally posted by pantelones View Post
        I agree, but it seems like it's not quite as simple as choosing N/A cams. It's more or less making a cam for the motor as apposed to building a motor around a cam.

        Also another really good article to read...




        Does anyone have a cam card for the VAC turbo cams? Seems like that would be some good info for the tread since it's not stated on the site. Also MFDOOM when you contacted VAC were they suggesting custom cams or just giving you the option?

        And if your wondering why I am bothering to post here, my next e30 IS going to be a turbo'ed m10 or m42... Was looking at buying buttchugz 84 318i awhile back, but slacked on it and it sold.
        I called and asked for specs and the guy told me about them and said theyd be good for about 14psi and then we chatted about custom grinds. I was talking to Jim at MM during the time about cams, lifters and about a full head. The deeper I get into school the more I think Im going to have to wait on cams.. Itll probably be 4+ years before I do anything else to the engine but when i do ill probably go with a full MM head. For now its tune and drive.

        Comment


          wow I guess I sparked a lot of conversation lol. Which is awesome for me! thanks for all the input! So from what I've been reading custom grind cams are probably the best thing to do but since I'm super in experienced with turbocharging a motor and understanding how the cams should be ground I'm probably just going to go with the VAC turbo grind cams for no and maybe later in life when I know more about it I'll go for the custom ones lol.

          So from what you all said the arrow rods are basically pointless for me to buy? I know the M42 internals are all forged and super strong but I figured I'll already be neck deep might as well get new rods since the rest of the motor is going to be basically new as well! I'm still up in the air about it so I don't know what I'm going to be doing as far as rods go =/ ....Honestly I still need to finish tearing my motor down and get it to the machine shop hopefully by the end of this month or early next month. That was over my winter break I can focus on getting that together :nice:

          The more I get into this the more and more excited I'm getting about it!!! I also believe I'm most likely going with a garrett gt28rs or a gt2871r for my turbo because that's what my friends 240 with his sr20det has and it responds extremely well!

          Thank you all again for the help and much needed input! Happy to know the boosted M42 community is a bunch of good people who pretty knowledgeable!
          -Dee
          5-lugged turbo 318is Barn car
          IG: @deebelmont

          Comment


            Originally posted by wazzu70 View Post
            A lot of the turbo cam info out there is from the early 80s when turbos were more exhaust restrictions than power adders. The old stock cams are best for boost assums you have a log manifold and a restrictive turbo with tons of backpressure.

            Some turbo cam info on BF.c http://forums.bimmerforums.com/forum...ht=Turbo%20cam

            Basically the moral of the story in the last article I posted.

            And good links/thread you started! QFT...

            There are basics to follow which are addressed in much of the reading material out there however it is up to the end user/builder to refine, thats where the experience comes in.
            Basically my dilemma at the moment... I don't have the funds to start playing around and actually working with engine builders yet. In time, in time.

            Originally posted by MF DOOM View Post
            I called and asked for specs and the guy told me about them and said theyd be good for about 14psi and then we chatted about custom grinds. I was talking to Jim at MM during the time about cams, lifters and about a full head. The deeper I get into school the more I think Im going to have to wait on cams.. Itll probably be 4+ years before I do anything else to the engine but when i do ill probably go with a full MM head. For now its tune and drive.
            Ahh I see, yeah this stuff isn't cheap... Again, funds are really the only thing holding me back. A manifold and intake would be a great project for me next year in my welding classes. ;D

            Originally posted by ccsdo5 View Post
            wow I guess I sparked a lot of conversation lol. Which is awesome for me! thanks for all the input! So from what I've been reading custom grind cams are probably the best thing to do but since I'm super in experienced with turbocharging a motor and understanding how the cams should be ground I'm probably just going to go with the VAC turbo grind cams for no and maybe later in life when I know more about it I'll go for the custom ones lol.
            Usually the company you work with can help you pick a cam, whether it be custom or cataloged. As stated before the VAC grind is much better than the stock cam, but it is not going to be perfect. There are fundamental differences between the N/A and turbo cam profile and just switching to that profile will help out a lot. Though, when you start upping the PSI and making a more efficient system, you can net greater gains, and reduce lag with a correctly designed cam for your specific set up. Personally though, I would go with a custom cam even for a low PSI set up as I would be the one making the manifold, and intake...
            sigpic

            A man chooses, a slave obeys... Would you kindly?

            Comment


              Originally posted by ccsdo5 View Post
              wow I guess I sparked a lot of conversation lol. Which is awesome for me! thanks for all the input! So from what I've been reading custom grind cams are probably the best thing to do but since I'm super in experienced with turbocharging a motor and understanding how the cams should be ground I'm probably just going to go with the VAC turbo grind cams for no and maybe later in life when I know more about it I'll go for the custom ones lol.

              So from what you all said the arrow rods are basically pointless for me to buy? I know the M42 internals are all forged and super strong but I figured I'll already be neck deep might as well get new rods since the rest of the motor is going to be basically new as well! I'm still up in the air about it so I don't know what I'm going to be doing as far as rods go =/ ....Honestly I still need to finish tearing my motor down and get it to the machine shop hopefully by the end of this month or early next month. That was over my winter break I can focus on getting that together :nice:

              The more I get into this the more and more excited I'm getting about it!!! I also believe I'm most likely going with a garrett gt28rs or a gt2871r for my turbo because that's what my friends 240 with his sr20det has and it responds extremely well!

              Thank you all again for the help and much needed input! Happy to know the boosted M42 community is a bunch of good people who pretty knowledgeable!
              http://www.full-race.com/articles/bo...fr-turbos.html :up:

              Comment


                Whether or not you should think about replacing the rods depends on the amount of torque you intend to make. Around 350wtq is when I would really start thinking.
                -Nick

                M42 on VEMS

                Comment


                  The oil tap on the back of the block is 1.5 pitch, but what size bolt? M12?

                  EDIT: Yes it is m12x1.5 for those wondering.
                  Last edited by jntar; 11-02-2013, 05:37 PM.


                  M42 turbo build.
                  http://www.r3vlimited.com/board/showthread.php?t=301330

                  Comment


                    Okay people I have more dumbish question for you all!
                    So I was talking to a machine shop today and asking what I should look doing for this engine. So this is what I think I'm getting done.
                    Block:
                    - Hot Bath
                    - 85mm over bore and hone

                    Head:
                    - hot tank
                    - 5 angle valve job
                    - deck

                    Then also get the crank polished.

                    My question is, is it worth it to get the head port and polished? He also said the price to port and polish can range from $500-$5000 so what exactly should I do in this situation? HALP!!!!!
                    -Dee
                    5-lugged turbo 318is Barn car
                    IG: @deebelmont

                    Comment


                      With the head you either do nothing or everything with regards to porting. I have dropped in a set of Catcams from VAC and their springs/retainers. Nothing more and there isn't alot stopping me from going 400hp at the wheels (probably will the next time I am at the dyno).

                      Porting the head will make it much more efficient and is only a necessity if you want to drastically change the engine operating rpm, i.e. shooting for 8000+ rpm's with valve train to match or if you are really trying to squeeze every last hp out of it.

                      I would stick to a deck and valve job for a mild to fairly wild build in all other respects. If you are going full wild, oversize valves, solid lifters, springs and cams to match. This should be backed up with ARP hardware everywhere, Forged Pistons and Lightweight rods.

                      The later model BMW heads don't benefit (AS MUCH) from minor head work like older engines because the casting is of reasonably good quality.

                      That is my opinion anyway
                      - Chris
                      Project M42 - 255 @ 19 psi

                      Comment


                        Lets talk colder plug options.

                        I have found that a gapable one step closer plug option is the NGK R5671A-7 (Part#4091). What other options are you guys going high boost going with?


                        M42 turbo build.
                        http://www.r3vlimited.com/board/showthread.php?t=301330

                        Comment


                          Hi, I'm sorry to throw this into the cold plug question but what's the easiest liquid source for watercoold turbos on the m42. I read some stuff in the e36 m42 forum about taking the heat exchanger plate out behind the throttle body. Makes some sense to me.

                          What setup do you guys have? Where does the water go back into the regular cycle?
                          Any recommendations?

                          I hope this wasn't discussed 10000 times before.

                          Comment


                            I am running NGK BCPR7ES sparkplugs without issues. Cheap as too.

                            I have essentially used the throttle body heater as my turbo cooling lines (it's all custom). I also have a bleed line from the front of the head into the top radiator hose.
                            - Chris
                            Project M42 - 255 @ 19 psi

                            Comment


                              NOOB question here, but where are you guys relocating your windshield fluid reservoir to? Sorry if it's been asked already.


                              ( . )( . )
                              fried chicken

                              Comment


                                Garbage can.

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