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T.J.
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« on: April 23, 2008, 01:02:03 PM » |
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I am going to build and install a Megajolt system and get rid of distributor. This way I will be able to adjust my timing on a 3D map instead of just based on whatever curve my dizzy has in it. I have the megajolt kit - I got the unassembled version, so I have a box, a circuit board, and a few bags of electrical components (IC chips, resistors, capsdiodes, etc.) that all need soldered to the board.
I also need to pick up a few Ford Escort pieces from a junkyard (coil pack, sensor, and EDIS module). Then the hard part will be to modify my crankshaht vibration damper to have a 36-1 tooth wheel on it and fit the sensor somewhere close by. This shouldn't be too hard, but if I can, I will try to get it fitted without pulling the engine - so that will up the difficulty level.
I may get a few HP out of the engine over my dizzy, and I certainly wont have to replace/adjust points anymore. Other than that I am just doing this for a fun project and the idea of plugging a laptop into my Mini to tune it just cracks me up.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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BabyBMW
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« Reply #1 on: April 23, 2008, 07:51:58 PM » |
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My son just put together 3 units and installed one in his buddy's race car. We took it to the dyno last Saturday nite and got 5 more hp by tuning the box on the lap top. I'm looking at putting one in my FSP wagon.
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GWR #92 Keep the Shiny side up.  |
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T.J.
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« Reply #2 on: April 23, 2008, 10:27:29 PM » |
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Steve,
Chuck was my inspiration for this. I had heard of Megasquirt, but not Megajolt, he showed me his trigger wheels and talked it up. I may need to go see Chuck for trigger wheel help when the time comes.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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T.J.
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« Reply #4 on: April 24, 2008, 12:01:10 PM » |
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http://www.autosportlabs.net/index.php?title=MegaJolt_Lite_Jr._Users_WelcomeAll it really does is replace your distrubutor with an electronic programmable ignition. So, instead of relying on the springs and weights inside your dizzy and your vacuum advance unit to provide just the right amount of timing advance for your engine, this allows you full control of how much advance at different engine operating points. I currently have a dizzy without a vacuum advance so I just have a 2D advance curve. With megajolt you can choose to go with a throttle position sensor or a manifold absolute pressure sensor to determine engine load, so you end up with a 10x10 map of advance values that the processor uses to figure out what ignition advance to use. Sunday, as I was buzzing down I-264 in a deluge my dizzy didn't really like the rain so much...that should go away with MJ.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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BabyBMW
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« Reply #5 on: April 24, 2008, 06:47:50 PM » |
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TJ, I'll get you in touch with Chuck when you need him.
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GWR #92 Keep the Shiny side up. |
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T.J.
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« Reply #6 on: April 24, 2008, 08:26:09 PM » |
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I know where he works, but if our schedules don't mesh up I'll be glad for the help.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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Cuchulainn
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« Reply #7 on: April 26, 2008, 11:29:46 AM » |
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I'd be really interested in knowing how this works out for ya. I seem to be constantly adjusting my timing, working on it today as a matter of fact.  |
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T.J.
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« Reply #8 on: April 26, 2008, 08:17:37 PM » |
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I'll post updates on this thread. I am soldering components onto the board now...doing it a few joints at a time since I am doing at work and worried about setting off the smoke detectors.
Not sure when I'll try the install, but it will be a little while. I still have to source some junkyard parts and then the fun part will be sorting out the mounting of the trigger wheel onto my crank pulley...hopefully I can get that done without pulling the engine.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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T.J.
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« Reply #9 on: April 27, 2008, 01:05:28 AM » |
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Soldering complete, I now have a fully assembled Megajolt box.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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MD_IN_UK
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« Reply #10 on: April 27, 2008, 08:41:07 PM » |
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Sounds good TJ. I still am out in left field though trying to understand how this system works. Maybe if you could try phrasing it all in simpler terms, so a numb nutz like myself could better understand?
Thanx
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T.J.
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« Reply #11 on: April 30, 2008, 08:06:01 AM » |
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The system replaces the distributor - does the same exact job though. It uses the coil pack and ignition module from a ford escort (EDIS-4). The way the ford system is set up this ignition module gets told by the ECU how much advance to use based on engine load and RPM. The megajolt system, essentially acts in place of the ford ECU in that it tells the ignition module how much advance to use. It uses engine RPM and either manifold absolute pressure or a throttle position sensor to determine engine load.
To figure out RPM and timing, a toothed wheel is fitted to the crankshaft pulley and a variable reluctance sensor counts the teeth as they go by. The toothed wheel is known as a 36-1 wheel. If you imagine w wheel with 36 evenly spaced teeth with one tooth missing that's what the wheel looks like. The missing tooth is used for the system to figure out where TDC for cyinder #1 is so it has a reference point to go on.
It essentially makes for a modern electronic ignition that is fully user programmable via a 10x10 matrix of RPM versus engine load.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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T.J.
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« Reply #13 on: April 30, 2008, 02:58:04 PM » |
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You only rebuilt the carb right? Didn't open up the engine?
Maybe your carb is set too rich and is making black smoke...oil smoke is more bluish...is your tailpipe covered in soot?
You can buy an assembled megajolt box if you don't want to solder it together...I am cheap though.
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Nothing is so bad that you can't make it worse by doing something rash or going berserk.
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