Guest ZmeFly Posted November 26, 2003 Share Posted November 26, 2003 Well I went on and decided to take a look at the boost controller, its a Hallman, well anyway pulled the thing apart and didnt find anything out of the ordinary, but the spring seemed worn so I found one at the hardware store and replaced it. Well heres where it gets a little crazy, first run out at the same place it was at before I watched my gauge hit 20psi Glad I had a dead eye on it as I let off the fuel rather quickly. Well to make a long story short, with either the old spring or new spring in the MBC, no matter what the setting it just lets loose. There is no adjustment at all. What the hell happened anyone know Maybe its time for a real boost controller. Quote Link to comment Share on other sites More sharing options...
vashonz Posted November 26, 2003 Share Posted November 26, 2003 Put the old spring back in? It sounds like you got a much higher rate spring. Quote Link to comment Share on other sites More sharing options...
Guest ZmeFly Posted November 26, 2003 Share Posted November 26, 2003 The old spring is back in, the thing is it wasnt letting me boost past 12 psi not its wide open, no matter what the setting is on the MBC, it goes till it cant. No tuning of the MBC what so ever. I dont know what gives. Quote Link to comment Share on other sites More sharing options...
Len Posted November 26, 2003 Share Posted November 26, 2003 You might try pulling your stock spring a bit. So it will provide a bit more back pressure to allow for a bit more boost. That's what I did with my Dawes MBC I was running 18 psi during the summer. During the winter I turned it down to around 15 psi. Quote Link to comment Share on other sites More sharing options...
Guest ZmeFly Posted November 26, 2003 Share Posted November 26, 2003 Before I put the spring back in, pulling it a little bit to give it some more tension. It did or didnt work I dont know. The begining problem was it was dropping boost. I removed the MBC, and put a new spring in and couldnt get an adjustment. Now with the original spring in the MBC, I still get no adjustment at all. Its at 20+ psi no matter where it is adjusted, its a older style Hallman. I dont get it, first it wasnt giving me the boost, now its giving me more then what I need. Quote Link to comment Share on other sites More sharing options...
Len Posted November 26, 2003 Share Posted November 26, 2003 Hmmmmm don't know what to say, Except try to bypass your MBC althgether and see if you get your stock boost. If so start from there. Could be a worn or cruded up MBC(you know they are not a quality made high ticket item ). Now to long of lines from your MBC to turbo and intake will cause a spiking (running high then going low boost). Might look and shorten your lines? Good luck Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted November 26, 2003 Share Posted November 26, 2003 I like the Turbo X/S dual boost controller...... Quote Link to comment Share on other sites More sharing options...
Guest ZmeFly Posted November 26, 2003 Share Posted November 26, 2003 Well when pulling it apart it didnt seem dirty at all rather clean actually. The MBC isnt hooked up to the intake at all. It has one hose going to the waste gate, then the other hose goes to a T and to two connections on the turbo. Is this right? Quote Link to comment Share on other sites More sharing options...
Len Posted November 26, 2003 Share Posted November 26, 2003 I've sept since I checked but I believe one of those lines from your "T" comes off of the underside of your intake for vac press. indexing. I'd make sure all your lines are air tight (no leaks for false readings), try squezing your spring. Could be too long/strong. But I'd still remove the MBC and see if you have stock boost as a reference point. If you have your MBC screwed all the way as far out as it can go; its gotta be to stiff a spring; air leak; or plugged to cause you to boost 20psi. Maybe your waste gate is frozen shut? I've run out of ideas, wish I could help. Quote Link to comment Share on other sites More sharing options...
Guest 81na ZX Posted November 26, 2003 Share Posted November 26, 2003 I've built quite a few ball-and-spring MBCs. What it sounds like from your original post is the new spring has too high a rate and/or is too long. Cut a couple coils off the spring and try it again. I've had this happen on all the MBC's I've made For me, I put it in, and boost way too much, 20+ like you, the reasoning is that the spring is too long and being compressed too much at the "lowest" setting. By cutting off a few coils, you allow for more slack area, for lack of a better term. And thus more room for adjustment. However, if you started with a 1.5" spring, and you cut it down to 0.75" and it still isn't working, the rate is too high. In that case, buy a new spring Quote Link to comment Share on other sites More sharing options...
Guest ZmeFly Posted November 27, 2003 Share Posted November 27, 2003 You guys were right, hehe I was just going to do an update and well thats exactly what it was. When I stretched the old spring I gave it to much strength. I have since mushed it for a lack of a better word and now its working properly again. Thanks for all the help. hehe Quote Link to comment Share on other sites More sharing options...
Dacelooper Posted January 7, 2004 Share Posted January 7, 2004 hi, i'm new to the turbo world and have a few questions. well after lots and lots of tinkering i think i got my 280zt running ok. Q1 - i finally got a Boost guage and found under WOT i start to build boost at about 3500rpm and peak at 5lbs at around 4500-5000... is that normal? Q2 - i want to install some of my new toy and raise the boost. i've had this granger valve for about 6months now and haven't put it in yet. i know you from reading forum that you run the line from your intake to the valve to the wastegate acculator. my question is where to the other two lines go that are attached to that same line go? shouldi just plug them? or run them together? any input is greatly appreciated. thanks. Quote Link to comment Share on other sites More sharing options...
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