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    #46
    so cut the throttle wire on the car, comes up on the revvs now. but i have a boost leak now, some how :/ take everything off tonight make bracket stronger. should have boost hopefully :)
    sigpicDiRTYE30-RALLYE30

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      #47
      Out of curiousity how did you run your piping? Positive Displacement blowers don't really like being far away from the intake ports, and long tubing runs can really hurt their efficiency. This could be part of your issues with not building boost. Also, how did you seal your tubing flanges to the supercharger. If your still using that thin gauge metal for the flange that will easily bend away under pressure and cause a huge leak. Your going to want AT LEAST 1/4" metal for that, but I would play it safe and go with 3/8" so you know it won't be flexing anymore.

      Oh, and what is the diameter of your crank pulley vs. charger pulley? That should tell you what boost you could expect, so you know how much your missing.
      Tinker Engineering - 2014

      Mica - 2000 BMW 323i - The one that started it all
      Fiona - 1975 BMW 2002 - The Definition of Project Creep
      Heidi - 1988 BMW M5 - The piece of BMW history
      Silvia - 2013 Subaru WRX - Stock, for now

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        #48
        Fuck yeah, Eatons. Loving this thread. I want to see the issues resolved.
        RIP: Delphin '89 E30 with S50 swap and lots of goodies :'(

        Then: '04 Evo 8 RS, 500 whp/420 wtq 2900 lb E85 AWD turbo shits 'n giggles

        Now: 2003 BMW M5 in Sterling Gray

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          #49
          I said this before. Supercharging is another ballgame on petrols, oldskool diesel is easy.
          Theres NO way miller this and that would do it.. You would need a standalone EMM.

          Oh, and.. If were following the 1bar boost = twice the power. Remember, the blower is stealing 30 hp.
          And then there is the heat..
          Last edited by Kvasi; 08-10-2012, 08:04 PM.

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            #50
            got any pics of how you have done the fmic piping? interesting build. good on ya

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              #51
              Well everytime i try to give it throttle it will revv up but then it will stop at 4800. I dont know how big the pulleys are i will measure them today. Im going to redo my my flange and bracket today with my buddy Kamotors, who has been helping this whole time. But he says that when i get boost my flange might be ballooning out causing the boost to go into the intake side of the blower causing that stutter.i did use the stock gasket and chrysler RTV to seal it. We also think that i could have a intake manifold leak and all my boost goes away. But that's kinda rare right? I have to reconnect the exhaust on the e so i can go get my tools but either today or tomorrow i will let you know whats going on.
              sigpicDiRTYE30-RALLYE30

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                #52
                its not uncommon for an intake mani leak. have you replaced the gaskets? if not they might be brittle and the added pressure can effect them alot.

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                  #53
                  OK. So. took everything off this morning, meaning bracket and manifold. might have had a small leak into the next chamber over, but not into the intake side. I reinforced the bracket a bunch so i could tighten and not have it bend. Put all of that back together, manifold with much more RTV this time. We did a boost leak check, and my blow off valve was leaking really badly. Took that out, one its not to good for the blower i read, or something and two it was leaking like crazy. Took that out and the car was running better, took it down the street and the outlet came off lol. Fixed that with a better clamp, took it on another test drive and still no boost, it needs a tune job. Anyways measured the pulleys they are kinda really small. 2.795in.. on the blower and 4 1/2 or 3/4 on the crank pulley i might only be getting 3 psi, because im barely reaching 0 vacuum. Does any one know of a crank pulley that could fit that's like 8in with the same or close bolt pattern, or even what pulleys i should be running? Another thing. Cannot take off blower pulley because its welded on. Thanks for the help so far
                  Last edited by TheBlik; 08-11-2012, 09:07 PM. Reason: ..
                  sigpicDiRTYE30-RALLYE30

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                    #54
                    Originally posted by e30leigh View Post
                    its not uncommon for an intake mani leak. have you replaced the gaskets? if not they might be brittle and the added pressure can effect them alot.
                    i have not replaced intake mani gask. but i sprayed carb cleaner on every fitting and the car didn't bog sown so im assuming that its fine.
                    sigpicDiRTYE30-RALLYE30

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                      #55
                      so here is how to calculate boost

                      "Boost (psi) = (PR x 14.7 x V / C/2 ) - 14.7 - I

                      PR is pulley ratio, crank pulley diameter divided by drive pulley diameter. e.g. The stock Jaguar M112 pulley is 3 inches in diameter, therefore 5.5/3= 1.83

                      14.7 is the pressure of the air we live in, we don't live in a vacuum, we live in 14.7 psi.

                      V is the volume of the Eaton blower for one rotation. The M90 is 90 cubic inches or 1475 cc. The Eaton M112 is 112 cubic inches or 1835cc. Turn it once and it pumps out 1.835 litres of air.

                      C is capacity of the engine in cc : 4000 cc for the 1UZ-FE. The C/2 is C divided by 2 - because for one rotation, a four stroke engine is only half way through a complete cycle. When the piston is up the top and starts going down, air and fuel go in, then it gets to the bottom and goes back up and compresses the mixture. That's one rotation. Then the spark plug ignites the mixture and it starts to go down again, it gets to the bottom and then goes back up again pushing the burnt mixture out the exhaust valve and returns to the top to start over again. That's two rotations.

                      I (capital "i") is an allowance for boost lost due to valve overlap. All engines have valve overlap; the intake valve opens before the exhaust valve closes - the incoming fresh air and fuel pushes out the last of the burnt exhaust gases. The 1UZ-FE has a small overlap of only 9 degrees. Nissan's RB26DETT has 14 degrees, Subaru EJ20 has 16 degrees and the turbo EJ20 has 14 degrees. The allowance is quoted as 5% boost lost for every 10 degrees of overlap. So for the 1UZ-FE at 6 psi boost, perhaps boost loss is 0.05 x 9/10 x 6psi = 0.27 psi lost - it's not much."


                      7speedshop.com

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                        #56
                        uh oh.....calculations say your only getting 1.007psi:( that would explain a lot.


                        7speedshop.com

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                          #57
                          can you have the blower pullie machined off or down and a new one welded on? or you could get a custom crank pullie? get it in alloy to counter the added rotation with less weight

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                            #58
                            Originally posted by kamotors View Post
                            uh oh.....calculations say your only getting 1.007psi:( that would explain a lot.
                            Really? I'm getting 5.6 psi before subtracting the overlap allowance.


                            Boost (psi) = (PR x 14.7 x V / C/2 ) - 14.7 - I

                            PR = 4.75 in / 2.795 in = 1.699

                            V = 62 in^3 (Eaton M62)

                            C/2 = 2.5L/2 = 1250 cc = 76.27 in^3

                            Boost = (1.699 x 14.7 x 62 / 76.27) - 14.7 = ~5.6 psi


                            This seems more in the ballpark just because the stock crank pulley is probably close (possibly a little smaller, but not drastically) to the original diameter of what drove the charger in it's original application.
                            Tinker Engineering - 2014

                            Mica - 2000 BMW 323i - The one that started it all
                            Fiona - 1975 BMW 2002 - The Definition of Project Creep
                            Heidi - 1988 BMW M5 - The piece of BMW history
                            Silvia - 2013 Subaru WRX - Stock, for now

                            Comment


                              #59
                              So i need a new pulley regardless. Also i didn't do research i'm retarded, the blower came out of a Benz c230, and apparently those are 1.8 liters so the small pulley works. Also their crank pulley is 7 and something inches so they can get 12 psi stock. So since I have more displacement therefore i need larger pulley, like 10-12in. to even get some boost to over come valve junk and the 30hp the blower is stealing away. What i figured, and i assumed, it always gets you in trouble, that its like a motor cycle chain and sprockets, the bigger crank pulley gives you more speed and then the small rear would give you more speed. But now math is involved :( hahaha. So any suggestions on what the dimensions are on an 12in crank pulley or how i could get those measurements?
                              sigpicDiRTYE30-RALLYE30

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                                #60
                                Originally posted by TheBlik View Post
                                So i need a new pulley regardless. Also i didn't do research i'm retarded, the blower came out of a Benz c230, and apparently those are 1.8 liters so the small pulley works. Also their crank pulley is 7 and something inches so they can get 12 psi stock. So since I have more displacement therefore i need larger pulley, like 10-12in. to even get some boost to over come valve junk and the 30hp the blower is stealing away. What i figured, and i assumed, it always gets you in trouble, that its like a motor cycle chain and sprockets, the bigger crank pulley gives you more speed and then the small rear would give you more speed. But now math is involved :( hahaha. So any suggestions on what the dimensions are on an 12in crank pulley or how i could get those measurements?
                                Damn dude! all the info is out there ...you dont take the time to read, plan and thats why you end up with this epic fail! I even posted on your thread and was completly ignored. read my blog...read the supercharged! book by corky bell....do you damn research.... why do people think adding roots type charger on a M20 is a piece of cake!!?? Its a LOT more work then adding a turbo if you do it right.

                                One more thing for it to be done right the throttle body needs to be located before the charger...(ask me how I know) of course dont listen to me what do I know about Supercharging the M20..how are you going to do that now?!? now that u located the roots charger under the exhaust which is just rediculous for a lot of reasons how are you going to relocate the throttle body? Why do you think you need a 3.5MAF? why cut the throttle wire? why use weak ass small gauge metal for mounts or sc output? I could go on and on...
                                Last edited by Denny; 08-12-2012, 08:00 AM.
                                Denny
                                ___________
                                1990 BMW red 325IC M30B35 all stock Girlfriends ride
                                1991 BMW black 318IC (M62b44 Megasquirt 2 ver 3.57)

                                Blogs:
                                http://bmw325e30.blogspot.com/ (restoration)
                                http://bmw325e30turbo.blogspot.com (Twincharge M20)
                                http://bmw325e30m62b44.blogspot.ca/

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