| Cytherea | |
|---|---|
 | |
| Participants | |
| Skills | Mechanics, Electronics, Soldering, megasquirt |
| Status | Active |
| Niche | Electronics |
| Purpose | Fun |
| Tool | No |
| Location | Nurdspace |
| Cost | Priceless |
| Tool category | |
Cytherea Property "Tool Image" (as page type) with input value "File:" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process.
{{#if:No | [[Tool Owner::{{{ProjectParticipants}}} | }} {{#if:No | [[Tool Cost::Priceless | }}
Interoduction
With this project I'm converting my '96 Suzuki Bandit from a carburetted motor bike to a fuel injected one. The engine of said motorbike needs an ideal mixture of gasoline and air to make the cilinders go boom. On the bandit, this is done by means of carburettors. This roughly boils down to the following principle. Engine sucks in air, carbuterror does some mechanical thingy to allow the right amount of fuel to get sucked in with the air. Ideal mixture reaches engine, stroky, sparky, boom. Ofcourse this is all very cool if you like easy stuff, but I like hard stuff. So, out with the easy, in with the hard.
Hard stuff
Of course, we still need the ideal mixture, because to much fuel per air makes for a smelly motorbike and you will visit the pumpingstation more often than you'd care for. Too little fuel per air makes your engine burn up. Yes ladies and gentlemen, fuel cools your engines. Bet you didn't know that. Anyway, we still pretty much want the same thing, ideal mixture, we just want it to be delivered in a way that's challenging for a nurd. So, the alternative is fuel injection. With fuel injection, an injector is mounted directly in front of the air intake port of your engine and blasts the engine with heavy loads of fuel as air gets sucked in. The engine swallows this mixture whole and starts revving up, begging for more. As the engine revs up, it sucks in more air, and now we have problem. More air, means more fuel, otherwize the engine will burn. We gotta cool that engine. So, how do we know how much fuel to give it to the engine? And how do we drive the injectors in the first place? The answer to the first question is not that easy (hard remember) so I'll save that for later. The answer to the second one is: We need an Engine Control Unit, or in american: ECU. The ECU is the device that determines what the engines needs, and gives it to her.
Challenges
To the readers that are still with me after this introduction, I salute you. In order to make everything work, I had quite some obstacles to overcome. Both mechanical and electrical in nature. In the past, I tried to build the ECU myself, but having not enough skills or education, I gave up on that path. However, for people like me, some guys with the proper skills and education developed a kit called MegaSquirt. When I jumped in in 2009 we were at Rev II, so that's the one I got. The cool thing is that I had to solder it myself, and it came with at least 100 components, so I had a lot of fun assembling it. The build guide was complete and very thorough and allowed for different hardware features depending on your requirements. (more about this later.)
- Assembling the ECU
- Fitting the fuel tank with a fuel pump
- Building the cable loom that ties the whole thing together
- Aquiring, calibrating and fitting various sensors
- Aquiring and mounting the trigger wheel
- Machining a custom fuel rail out of aluminium extrusion
- Removing the carburettors
- Mountin throttlebodies from a different bike
- 3D print a prototype of a simple mountpoint for the trottle cables
- Having said design machined by a friend
- Having said design laser cut by profzon (y)
- And probably some more
Assembling the ECU
Assembling the ECU wasn't that hard. I ordered a kit off of https://www.diyautotune.com/ which included the PCB, all the components and the casing. I also orderd to stimboard, used to simulate different sensors, and actuators. Assembly was pretty straight-forward, as the instructions were very clear (steps) and it would have you test the board at different stages of assembly. I took particular care in soldering everything, as it's supposed to last and I dread the idea of having to find a cold joint on the ECU.