Forget watching porn and whoring around on MySpace, we've found a much more productive use for the Internet: Helping us to buy, build, install and tune MegaSquirt's Do-It-Yourself (DIY) engine management. Yes, you read that right: homemade stand-alone engine management. We're going to build an ECU that can do anything the high-end, high-dollar ECUs can do-at a fraction of the cost. It'll just take a little bit of gusto and the ability to do some research on the Internet to make it work. So, fire up your browser, put on your safety glasses and grab your lab coat, because we're building and installing our own fully programmable, fully capable ECU.
Sold for around $200 as an "experimental Do-It-Yourself universal programmable electronic fuel injection controller," MegaSquirt is a powerful and inexpensive engine management system (EMS) that can be programmed/configured to work with just about any car (usually with the stock sensors) to control fuel, spark, accessories, nitrous, water injection, boost control, knock control, idle and just about anything else you can think of (as long as it can be controlled by an ECU). It's flexibility allows it to be used as a stand-alone ECU in place of the stock unit, or as a piggyback to control fuel, spark-leaving the other, more mundane calculations to the stock ECU. But nothing in life is free, and in the case of this particular engine management, you might spend a lot less dough than with other engine management options, but you'll have to work a little harder (ok, maybe a lot harder).
The MegaSquirt ECU is sold for about $330 assembled or for $200 as a kit that includes a case, a motherboard, and a jumble of resistors, diodes, MOSFETS, LEDs, and all kinds of other fun stuff. Don't know what those things are? Even more reason to assemble it yourself. The choice to assemble it or not isn't merely an economic one. We regularly get letters here at 2nr with readers asking how they can learn to tune engines. Well kids, this is an excellent way to start. Even if it is never installed on a car, just putting it together will teach VOLUMES about how fuel injected cars work. It's kind of like those 100-in-1 electronics kits some of us built as kids-only a hell of a lot cooler and more useful. But be warned: even buying the pre-assembled version may not prevent you from having to make mods to the ECU itself (soldiering required) to work with your specific application. Some vendors on the Internet assemble and sell MegaSquirts that are configured for specific applications, however.
The ECU is sold as an "experimental" ECU, which means the user needs to figure out how to make it work for their car. In other words, it doesn't come with instructions on how to make it work with any specific vehicle. In fact, the ECU doesn't come with anything other than a box and a receipt. But don't fret, that's where your Internet browser comes in.
Everything other than the actual ECU is downloaded from the Internet. The manuals, firmware for the ECU, tuning software, data logging software, etc. are all open-source shareware that can be downloaded free of charge (until cable and phone companies start charging extra for downloads). What is great about this is the programs are constantly being improved and updated by the users who are both electrical and automotive gurus. The people who write the code that the ECU operates on are actually using it on their own cars and making real-world improvements to the software as they go. And these electrical wizards are only a few clicks of the mouse away in case you have problems or questions.
Additionally, the MegaSquirt website is chock full of information on tuning in general, and just about everything you could ever know about the MegaSquirt. But that's nothing compared to the wealth of collective knowledge on the MegaSquirt forum. Here, the programmers, users and perspective users share experiences and help each other set up their hard/software. In fact, almost any popular tuner car you can think of has probably been MegaSquirted before. Chances are high that someone else has done all the footwork for you and posted step-by-step instructions on the MegaSquirt forum. Even if your application is unique or custom, with the combined knowledge of thousands of other helpful "squirters," it's shouldn't be too difficult to get your rod up and squirting.
Getting ready with A little Pre-Squirt foreplayIs there any better way to test out a DIY engine management system than in a car equipped with DIY turbo system? We didn't think so. We found a Mazda Miata with a freshly installed turbo that was in need of some type of fuel and spark management. The owner is a cheapskate who's always looking to save a buck and lives on a shoestring budget, making his car a perfect candidate for a MegaSquirt install. With a guinea-pig car secured, we planted ourselves in front of the computer and started doing our homework.
The first step is to go to the MegaSquirt website and download and print the MegaSquirt manual and assembly instructions. After doing that, it's a good idea to search the forum to see if there are instructions and info for installing it on your application. There are dozens of different soft/firmware options for the MegaSquirt ECU, meaning that there are lots of different programs that may or may not work with your car. Out of the slew of programs that people use, there are three popular ones that are used almost exclusively. They are the standard V3.000 code that comes loaded on the chip when you buy the MS-I ECU, MSnS-E code, and MegaSquirt-II code. Additionally, there are two different ECUs processors available: MegaSquirt-I and MegaSquirt-II. The V3.000 and MegaSquirt-II (MS-II) code will work with both the MS-I and MS-II ECUs, but the MSnS-E code will only work with the MS-I ECU.
All these codes and acronyms may sound a little overwhelming, but it's really not that complicated. Just do a little research and purchase the version of the MegaSquirt ECU that will work best for your application: MS-I or MS-II. The different codes all have very different features and options, so pick wisely. The easiest way to make sure you get the best one is to visit the MegaSquirt forum to look around, ask questions, and find others who have already done what you plan on doing. We did just that and logged on before making any purchases. Much to our pleasure, we found that several other people had already MegaSquirted several Miatas and mapped it all out. They were even nice enough to provide step-by-step instructions on how to modify the ECU and actually install it in the car.
As it turns out, because of the type of ignition system the Miata uses (wasted spark), it is much easier to use the MS-I ECU with the MSnS-E firmware in our application. Using the MS-II would require additional hardware, modification and trailblazing, none of which we were willing to pursue. With the decision made on which ECU version to buy, we ordered up our unassembled MS-I, and then downloaded all the appropriate software and manuals. This is a good time to locate a complete set of wiring diagrams. They aren't all that hard to use and will help immensely. They may look intimidating at first, but automotive wiring diagrams are fairly easy to read and it's often simply a matter of identifying a wire by its color and tracing it to the ECU or sensor. Properly schooled and outfitted, we began the assembly.
We initially planned on building, installing and tuning the MegaSquirt in one installment (and we could have), but the tuning Gods weren't shining on us this month. The victim Miata suffered an electrical snafu while we were prepping the car for the install that wiped at a sensor and an igniter before we could even get the ECU in. The problem was our fault and had nothing to do with the MegaSquirt. We've ordered replacement parts, but unfortunately we'll have to wait until next month to get it installed and tuned.
Unable to actually install it, the last thing we could do was download the firmware onto the ECU. It took only a few minutes and gave us no problems. The MSnS-E code that we are running is highly developed and regarded by those who use it. It has many advanced features and has more being added all the time. It is a stable firmware and there are hundreds of people that are running this code on their daily drivers. With its excellent track record and lots of real-time support from true enthusiasts, we're excited to see how this $200 stand-alone will pan out. We'll be back next month to get this thing to the dyno for tuning, and see how well it plays with our homebrew turbo Mazda.