Input Section Construction & Testing
***Before Starting this section of assembly, REMOVE the processor from the 40-pin socket - use a thin screwdriver and pry it from the socket, first one end, then the other - place it back on the foam pad it was shipped with.***
***Be sure to observe the correct orientation of all diodes and capacitors. Unless you are blind or stupid, there really isn't a way to screw up as long as you pay attention. The proper direction is clearly explained in each step that involves requires soldering one to the board, and the silkscreen on the board shows the "+" for capacitors, and "stripe" for diodes.***
Complete steps 43-49.
Now comes a decision. Megasquirt allows you to choose how you want to setup your "tach" (rpm) signal to megasquirt, via either a “Hall” sensor, or “VR” sensor. The one you want is “VR” sensor, as this is what the factory turbo distributor uses. However, Megasquirt does recommend installing both circuits and selecting either/or by “jumpers”, but you don’t necessarily need to install both.
If you want to install both circuits, complete steps 50 ( “a” only) & 51.
If you only want what you need, complete step 51 ONLY.
I installed only the “VR” circuit (step 51), as this is the only input i'll personally ever use. If you THINK the possiblility of ever having to sell your megasquirt, you may want to go ahead and install the Hall sensor circuit as the future potential buyer may need that type of input. You arent loosing or gaining anything by installing it, as you already have the components in the kit...will only cost you a few minutes of soldering.
Here are some things to pay attention to under step 51 for installing the VR sensor input circuit.
“g”à Install the “trimmer potentiometers” with the adjustment screw pointing towards the heatsink. Turn the screw on “R52” and "R56"
all the way counter-clockwise until you hear a "click"
.
“k” à Use CAUTION when soldering these, as the “leads” are very thin and you can accidentally “bridge” these by using too much solder. Clean your tip before installing, and use the solder sparingly.
Complete Step 52 by installing the following jumpers for the “VR” circuit.
*Jumper
VRIN to
TACHSELECT on the bottom side of the PCB (near the DB37, opposite the heat sink.)
*Jumper
TSEL to
VROUT on the bottom side of the PCB, near the center.
Complete step 53 by installing the map sensor. This mounts from the bottom of the board.
Finish assembly of this section by completing step 54, then we move on to testing.
Re-install your processor (40-pin), DB-9 cable, and stimulator. Open Megatune and select Real-time display (same as from “Clock Circuit” testing).
You can now turn the adjustment knobs on your stimulator. You should see the values on the screen change as you turn the knobs.
Follow step 55 for testing each value (RPM, EGO, Map, etc.).
If everything tests fine and all values respond, unplug the stimulator and DB-9 cable and move on to the next steps.
If not,
STOP, go back and assure all components are installed and properly orientated.
Output Section Construction & Testing
***Be sure to observe the correct orientation of all diodes and capacitors. Unless you are blind or stupid, there really isn't a way to screw up as long as you pay attention. The proper direction is clearly explained in each step that involves requires soldering one to the board, and the silkscreen on the board shows the "+" for capacitors, and "stripe" for diodes.***
Complete steps 56-64.
Step 65-
The only thing to solder on from the component list is “Q16”. DO NOT install R43 OR R57. R43 and R57 are NOT needed when running a single coil from the megasquirt. For more details on this, refer to the MSnS hardware manual by clicking the link below.
MSnS Extra Ignition Hardware Manual
Be sure that you are using the mica-insulators and heat-sink grease when installing Q16.
Install a “jumper” where “R43” would normally sit. Use some decent gauge wire (nothing very thin).
Install a “jumper” between IGBTOUT and IGN. This is located on the bottom of the board between where R43 would sit and the DB39 connector. You can use a snipped lead from a resistor or other electrical component.
We now want to install a “jumper” between IGBTIN and the top of “R26”, but with a 330Ohm resistor between them. You can find a resistor at your local radio shack for a few cents. You want a 330-Ohm, ¼ watt resistor.
First, solder one end of the 330 Ohm resistor to the top leg of “R26”, which is located right beside the “proto area” on the board, and beside the “D14” LED light. You can locate the resistor in the “proto area”
Next, place the other leg of the resistor through a hole in the proto area. On the bottom of the board, solder one end of a piece of wire to the end of the 330Ohm resistor. If you purchased a “kit”, then you should have a piece of jumper wire just the right length. If not, find a small piece.
Solder the other end of the wire to IGBTIN. This is located right beside where we just soldered a jumper for “IGBTOUT & IGN”.
Complete steps 66-68.
Complete step 69 & 70.
Megasquirt recommends installing BOTH PWR circuits.
NOTE: When installing “Q9” and “Q12” under step 69, make sure that the metal tab of each does not touch the heatsink. Use the special plastic protectors and washers when installing these. You can use an ohmmeter to verify that there is proper resistance between the two.
Complete step 71.
Note” Megasquirt states to mount these on the heatsink, but from my experience it’s nearly impossible to bend the leads in order to do this. They break VERY easily when you try to bend them. I installed mine “straight up” with no issues. The choice is yours…
Complete steps 72-80 (skip 78-79 if you bought a kit that includes the case).
Install the LED’s and bend them to match the holes on the case end.
Congratulations!!! YOU JUST BUILT YOUR MEGASQUIRT!!!
You can now fully test your megasquirt by following the paragraph after step 80. If all tests ok, we can move on! If not, STOP, go back and assure all connections are good, all components are in and positioned in the correct orientation.
Before continuing to wiring and tuning, we must first install the MSnS code so we can control both fuel and spark. To do this, we must visit the MSnS website at:
www.msextra.com
Scroll down the page and find the link that says “ How to load the MS-1 Extra code to the MS ECU”.
The page is very detailed on how to download the code, so I won’t go into detail. Just be sure to read the directions and follow them. The “boot loader" is located right beside the main 40-pin chip and right above the “proto area”
Once you have successfully loaded the new code, continue to “Wiring Megasquirt”.
