Megasquirt Info and Install

Builds
1

For those who don’t know; Megasquirt is a DYI standalone management computer that can be used with virtually with any car. When it first came out it was only used as a fuel computer. Over the years megasquirt has evolved into a complete standalone system that rivals the expensive aftermarket standalones that we see today. Heres a quick list of features megasquirt can control: fuel, ignition, iac, tps, fan, water/meth injection, nitrous injection, propane injection, boost control, Flex fuel, Knock settings, extra injectors, wideband auto-tuning, launch control, extra injector/s,datalogging, and much more.

There are so many possibilities with megasquirt so I’m just going to get into the basic info. Megasquirt uses a speed-density based system. In order to run properly, megasquirt will need to know coolant temperature, air temperature, throttle position, exhaust output (o2), manifold pressure, and ignition trigger. Megasquirt uses a built-in MAP sensor that can read up to 21psi. (You can easily switch upto a 4-bar MAP if needed). Megasquirt can use your stock sensors stock along with IAT and CLT GM sensors. These 2 sensors are very common and inexpensive. You can probably get away with using your own IAT and CLT sensors, but extra conversions have to be made etc…

There are several versions that support several options for megasquirt. The hardest part is figuring out what’s best for your setup. Depending on your needs, you can start out with a Megasquirt I processor w/PCB2.2 for about $140 unassembled /$240 assembled or go with the most recent Megasquirt II processor w/PCB3.0 for about $250-$300unassembled/$400 assembled. It is also able to mix and match (ex> MegasquirtI on a V3 board) to save money when you don’t need the added features.

Megasquirt connects to your PC or laptop via DB-9 serial cable. It uses open-source software called Megatune that can be downloaded off the internet. Megatune for allows you to setup VE, Spark Advance, and AFR tables. MegasquirtI will allow for a 64 point map (8x8) for each of these tables. MegasquirtII will allow for 144 point map (12x12). The V3 board allows for both low and high impedance injectors. Megasquirt supports/can control the following ignition modules: GM HEI, GM DIS, Ford EDIS, Bosch 0 227 100 124, MSD 6A, and Direct Coil.

This is about as far into megasquirt knowledge as I’m about to go.

Any more info on megasquirt can be found:
http://www.megasquirt.info/
http://www.bgsoflex.com/megasquirt.html
http://www.msefi.com/
http://www.diyautotune.com/

2

Project preparation

Due to lack of aftermarket support, this has been THE standalone solution for probe owners. There is a huge amount of knowledge and support on the probe forums (not to mention bulk buys on assembled units every now and then). Some members had a lot to do with the development of megasquirt into a full standalone management system – particularly with the wheel decoder software which paved the way for ignition control.

I had plenty of things to consider when ordering megasquirt for my turbocharged probe. I have the mazda 2.0 FS02 (same motor found in the mx6 and mazda protégés). It uses fords EEC-IV management system w/TFI ignition. Back in the day when I was all about budget turbo systems I used an upgraded pump, larger supra injectors, and safc for fuel control. For timing, I simply clocked the ditsy back to retard timing a slight bit to avoid detonation. This was a very conservative setup that obviously held bottlenecks. I came to learn that the SAFC did very little for my car. The stock ecu would “learn” it which disabled any real tuning. It was pretty much only getting the 440cc injectors to idle. Another bottleneck was the stock MAF sensor (http://www.njsr.org/pics/albums/userpics/10705/normal_100_1665.jpg). Now that I have a built motor and upgraded to a bigger turbo system, its time to move on. After researching custom standalone systems and failed attempts on getting EEC tuner programs to work on my car, I finally decided to go megasquirt.

Figuring out what setup to get was the hardest part. I started with my basic requirements of a standalone and worked from there.

Fuel options were easy simply because megasquirt (PCBv3) can control pretty much any type of injectors.

Ignition control was a different story. I wanted full control over ignition as well as a stronger spark. My first option was to convert ford’s EDIS4. EDIS is very popular due to the fact that its one of the easiest universal ignition control methods for megasquirt. In order to run edis you will need an edis module, coil pack, crank position sensor, and 36-1 tooth wheel. All these parts can be obtained from the junkyard pretty cheap. In my case, edis4 would completely replace the stock disty – a freeze plug would have to be put in place of the disty hole.
(http://www.we-todd-did-racing.com/wetoddimage.wtdr/wODcwNjE4NnM0MTNkZmQzMXk1NDE%3D.jpg) EDIS4 uses a wasted spark method. It lacks features such as rev limiting, launch control, etc. After some thought, I decided to go with a Direct Coil or MSD6A setup. This would give me the same advantages as EDIS4 with the addition of having rev limiting and launch control with less work involved.

At this point with the given requirements figured out, I decided to go with the Megasquirt I processor with PCBv3. The next question was if I wanted to ditch the stock ecu and let megasquirt control everything. I figured since the stock ecu does a good job at controlling fans, idle, accessories, and emissions Id just leave it in. This gives me less things to worry about as well as more freed up programmable outputs from megasquirt.

3

Starting the project

Here are some pics of my assembled megasquirt w/ wiring harness:

http://www.njsr.org/pics/albums/userpics/10705/normal_ms1%20005.jpg

This pic shows the wiring harness, connector, and built in MAP sensor.

http://www.njsr.org/pics/albums/userpics/10705/normal_ms1%20006.jpg

Here’s a pic of the serial data cable that connects to the laptop as well as the LEDs for Inj, Warmup, and Accel status.

Figuring out the wiring wasn’t too bad. This is a generic wiring diagram off of megasquirt’s website:

http://www.megamanual.com/v22manual/extwir.gif
extwir.gif796×662

Going from there, you can start labeling your wires:

http://www.njsr.org/pics/albums/userpics/10705/normal_ms1%20008.jpg

Next, you need to figure out what wires need to be spliced, cut, etc. It’s always nice having a pin out of your stock ecu for this reason:

http://www.njsr.org/pics/albums/userpics/10705/normal_ms.jpg

Lastly, here’s the final wiring table:

http://www.njsr.org/pics/albums/userpics/10705/normal_ms1.jpg

This is as far as I’m going to get for now. Unfortunately my car was hit by a county vehicle a few months ago. My car will be going away soon for body work as well as a new paint job. I’m going to wait to get the car back before proceeding with anything else.

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Reserved 1

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Reserved 4

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how much for the assambled v3

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Is this the new release that allows for coil on plug or still the one that doesn’t support it…unless u want to convert to plug wires

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v2.2 CAN do COP, but v3 does it easily. On 2.2 you need to make some sort of circuit, and it also needs a seperate circuit to run VR sensors. V3 essentially has VR sensor capability built in. All you have to do is jumper a terminal or 2.

I’m running VR and COP wasted spark on my GTI right now, it works awesome, but it took some messing around to figure out how to trigger the coils as mine are 300000x more retarded than any other car.

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LOL…cause i know its uber cheap compared to others and just as powerful…the only thing stopping me was the PITA for coil on plug

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ive been really developing an interest in megasquirt, but no one has tried it on the focus because they claim the SCT software to be the “end all be all” way to tune.

cant wait to see the progress darryl :tup:

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There is a reputable dealer selling it for $333 for the v3.0 and $30 for the enclosure.

NeonGLH is running it. I might be blowing up his spot but, link removed at request of owner

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I have used this system 2 times, and it works 100%. Very straight forward, inexpensive and a nice project if you like to solder

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WORD…a f-ing Apexi AFC Nano is more expensive…can the v3.0 control like v-tec or variable manifold switch over points

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maybe a little :gay:

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If anyone has any questions about megasquirt, feel free to contact me. I have been using it for a year now, and I absoltuely love it. I tune my own car, and since I know the software, i am tuning at least 2 other people’s cars’s this coming year.

Also check out www.msefi.com. It is the best resource for the hardware/software.

If you want the hardware, the best place to get it is from www.rs-autosport.com.

–mark

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megasquirt is for the hard core people.

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0H noes! I has betrayed t3h secret neon broverhood! How shall I ever live with this shame on me?!

In all seriousness, NeonGLH has had some notable results with it.

I wouldn’t say hard core, but it’s not for the feeble minded.

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