The MegaSquirt Thread

I've had a fair few people ask me questions about MegaSquirt ECU, so I thought I'd share some of my knowledge and experience. The focus of this thread will be mainly on the MegaSquirt 2 product and the MegaSquirt Extra (MSExtra) firmware (Fuel + Spark) instead of the older MegaSquirt 1 product and fuel only firmware.

Introduction - What is a MegaSquirt?
Megasquirt is a range of standalone engine management systems. All systems are intended for DIY install and most installs are self tuned. With Megasquirt you get the opportunity to learn how engine management works and gain full tuneability of your engine. Be sure to read the documentation here and on vendors' sites to see which of the product range is right for you to get the best results.

MegaSquirt can pretty much run on any motor, 1 cylinder through to 12 cylinders, powering cars, bikes, boats and even jetskis!



What features does the MegaSquirt have?
# Speed Density, Alpha-N and Hybrid Alpha-N (both SD and A-N algorithms hybridized) Supported
# 2 Ignition Inputs (for dual wheel ignitions)
# 4 Spark Outputs (Up to 4 Cylinder Coil On Plug, up to 8 Cylinder Wasted Spark)
# Rotary Ignition Support
# Enhanced Acceleration Enrichment (EAE)
# Boost Control
# Knock Control
# Launch Control
# Flat Shift
# Tachometer Output
# Fully Adjustable Rev Limiter
# Table Switching
# 4 General PurposeOutputs
# 4 General Purpose Inputs (2 analog, 2 digital)
# Support for Flex Fuel
# Optional Realtime Baro Correction
# Closed Loop O2 Correction
# Plenty of Proto Area, add your own customizations!

Check out more features here: http://www.msextra.com/doc/ms2extra/MS2-Extra_general.htm#features

Where can I buy a MegaSquirt?
I personally bought my MegaSquirt unit from DIYAutoTune, and I recommend them to anyone else looking at getting a MegaSquirt in either kit or assembled form. Check out http://www.diyautotune.com

Where can I find MegaSquirt Documentation?
You can find all the information you will ever need in the MSExtra Manuals, located here: http://www.msextra.com/doc/ms2extra/
Some fore warning, the manuals contain massive amounts of information and at times it gets really daunting. However, 99% of the time, if you read the manuals and follow them correctly, you will be fine.

Should I buy MegaSquirt as a kit to save some money?
This depends on how much you like soldering and electronics in general. I believe if you can wire up a car stereo correctly and can read/follow an instruction manual, you should be capable of building a MegaSquirt. I bought the MS2 kit with a pigtail connector for $425 shipped (from DIYAutoTune), the preassembled kit was $600+ at the time, so I opted for the DIY approach since I'm familiar with electronics and I'm a tight ass ($200 saving bought me a wideband!).

It took me 4 hours of soldering and double checking components along the way, I then spend 2 hours testing various power plans on the board while supplying power from a bunch of AA's (If you've soldered something wrong, AA's dont have the oomph to blow things up epically) before powering it up on a proper power supply. If your not big on soldering or you just want to save time, buy the prebuilt, the great AUD at the moment makes them a steal.

What software do I need to tune the MegaSquirt, and how much does it cost?
I personally use TunerStudio by Phil Toban, it's free, it's customisable and most of all, it's easy to use! You can check out TunerStudio here: http://www.efianalytics.com/TunerStudio/



Is there any thing else I should know?
Yes, you should be aware that once you have installed a MegaSquirt and learnt enough to tune it to drive around, you will be addicted to tuning! This is just like modifying the rest of cars, you will find yourself wanting to try something else, or experimenting with maps or spark advance or rev limiter types. I get odd looks as people see a serial cable running from the boot and in through the sunroof or passenger window [:P]

Bottom line, these things are addictive! You HAVE BEEN WARNED!





I'm slowly working on a write up on how to install the MegaSquirt into an 4AGE AW11, and eventually, 1MZ AW11. So I'll post them here when they are completed.

This post will be edited as I have time to add more information or answer questions

14/12/2009 - Added to Intro, Kit Vs Assembled, Addiction warning.
15/12/2009 - Added Features list

Nice one, Aaron. I for one will be very interested - I've had MegaSquirt on my project list for a few years, just waiting for some spare time to do something about it.

quote:

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Originally posted by fredhoon
I'm keen to hear more about how you have it running on your car:
batch or sequential fire, all stock sensors & dizzy? wide or narrow band o2, controlling tVIS using an aux output?

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Injectors are currently batch fire, I'm using all stock sensors, I still have the AFM just for the IAT sensor. The stock dizzy and igniter are used, however I've bypassed the igniter output and I'm driving the coil directly. Using an Innovate LC1 Wideband in the stock O2 sensor location. TVIS I haven't got off my ass to do yet, it's a case of wiring up a transistor to one of the spare I/O pins and setting an event trigger for turning it on and off based on RPM.

quote:

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Originally posted by fredhoon
Also waiting for a writeup/worklog of you installing an eePC & 7" touchscreen mounted in the dash for realtime info and tuning!!

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Once the 1MZ is in the AW11 and laying rubber, I'll get started on the EEE PC thing, maybe they will be cheap enough for me then

quote:

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Originally posted by dylmrt

oooh maybe we should get one for the aw11 20v :)

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That's why I bought one, just never got as fas as putting the 20v in the car [:p]

I might take a few videos tomorrow of the MegaSquirt running in my AW11. Gotta do a video of the spark cut limiter

quote:

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Originally posted by Knightrous (in the photography thread)

I've also been considering on getting some xbee wireless serial modules to make communication from the laptop to the megasquirt wireless

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I thought about this too but the electrical environment in a car is an EMI nightmare, and there's a couple of substantial shields between the boot and cabin. I fitted an LC-1 module near the AFM with the main wiring into the boot and the serial cables into the cabin, and routed a twin audio coax at the same time for the ECU serial data. I put a 2.5mm stereo line socket on the cabin end of this cable and use the LC-1 data cable to connect it to the laptop.

Aaron

This is awsome thread.. will will be looking into this for next year as a deffiniant!!! the more info the better... thanks mate.. this is a good idea..

DOM

The MegaSquirt can do Alpha N (running on TPS alone), how ever with a small vacuum tank in line with the MAP sensor, I think you will be able to run it as normal Speed Density without any problems. However, I could be wrong.

At least I know that I can have something to fall back on if I can't get it to run on the map sensor.

Yes, full standard loom and sensors. I ended up running 1 new wire seperate to the standard loom to drive the coil. The reason I did this is because I wanted to use spark cut for rev limiter, using the standard ignition system, the igniter is a smart unit, if it detects loss of signal from the ecu, it will continue to do the spark itself, but at 10' of timing. This basically overrides the spark cut, I planned to just by pass the igniter right up close to the unit but due to wiring diagrams of the igniter not making sense, I just ran a new wire.


So if I understand this correctly you did not use the standard toyota ignitor to run the coil. Does this mean that you can run the coil directly from the Megasquirt? Does it have an inbuilt ignition module?


Now, one thing to remember is that the MegaSquirt isn't a plug n play unit. There is a steep learning curve to them and there is a lot of documentation that can really overwhelm you when your new to it all. The MegaSquirt is cheap because it requires the user to do a lot more work, and sometimes you have to try things out for yourself as there isn't an ABC guide to doing it. I'd advise you buy a pre-assembled[url='http://www.diyautotune.com/catalog/megasquirtii-engine-management-system-wpcb3-assembled-unit-p-65.html?osCsid=e8da6b263be77a5437a8b9a1cbb4037f']MegaSquirt2 on v3.0 PCB[/url] and a [url='http://www.diyautotune.com/catalog/megasquirt-pigtail-harness-p-114.html?osCsid=e8da6b263be77a5437a8b9a1cbb4037f']18" pigtail loom[/url] from DIYAutoTune. If you ask nicely, they will probably even install the MSExtra firmware for you .

I don't think i'll have a problem getting my head around it. I have wired up quite a few Haltech's before. The hardest part might be entering the settings into the ecu to get the correct trigger angles to fire the injectors and ignition

There is also a new option from DIYAutoTune, it's there own rolled version of the MicroSquirt but in a form factor for PlugNPlay (PNP) applications. They have one for the Toyota based on the 52-pin ecu's located [url='http://www.diyautotune.com/catalog/diypnp-nippon-denso-52pin-unassembled-kit-p-390.html?osCsid=e8da6b263be77a5437a8b9a1cbb4037f']here[/url]. I've no experience with these unfortunately, so you'll be pioneering it yourself

This sounds pretty good too, I would presume that all the ECU's with this plug run all the same wiring pins or either you have to wire them up to suit your wiring loom. Now that you have thrown this into the mix I am liking the idea of a plug in ecu, so that if ever the cops defected me I could just swap the factory one in and away you go!

If you still have your stock motor in the car, buy the megasquirt and get it running on the stock motor first, this gives you a chance to work on an easy, already running motor that is problem free. Once you've had a few weeks of tuning and setup up the stock motor, you should be clued up enough to tackle an exotic balls out 4AGE

Yes this is exactly what I intend to do!