Diary of an ECU and Electronics Rookie

This thread is just my thoughts so far. This is my first year in FSAE.

The engine we're using is a 2008 Yamaha R6. The engine runs with the stock ECU and aftermarket fuel pump. We revved the engine up to only 8000 rpm since we only had the primary fuel rail connected. We have a Land&Sea engine dyno.

This is where I come in. I'm brand new to ECUs and was basically handed the Motec M84 to make it work. We've got the wiring diagram done, DTM connectors, and the injector and coil sub harnesses completed.

By the end of the week we should have the ECU connected to the engine and will start off with calibration. I'm writing all this since I haven't seen a thread that documents a rookie's experience in FSAE. Thoughts and suggestions?

Ref/sync calibration can be taken care of in <10minutes. I recorded a video for my team to on how to take care of it quickly, including a simple CRIP calibration, and I can post it later. It's a bit poor because it was ~3AM and I never had a chance to redo it. But it should definitely help you.

I also have a few documents that should be able to help you (warning: requires reading). I'm putting together a large document for my team on simple ECU stuff and wiring, and once I finish that I'll probably post that on the forums. Once I finish that...

And if you have any questions regarding the wiring, feel free to ask.

Final note, you should be able to do most of the wiring without the components you listed. Personally, I'd start from the AMP Superseal connectors on the M84 and branch out from there. So cut all of your wires first. Always cut long. You should have a general idea where the sensors on your intake are going, so if you leave a little extra length you should be able to get most of the wiring done now, and terminate the ends later.

Thanks Dylan. The wire we've cut to length are the ones assigned to a sensor or cylinder. We're leaving (until the car is running) the input/output wires in loops in case we want to integrate things in the future. Is this recommended or would you just build a new wiring harness for a new car? We thought about doing this but it seems expensive and time consuming.

It is strongly recommended to wire in extra inputs/outputs for future expansion. +1 for modularity. However, be careful with how many you wire in and how long the loom is. If you only use one aux output, there may not be a need for you to wire in the remaining seven. Unless you have plans to use that many in the near future. Now, if you wire in a few, plan for where they are going to run to to keep things neat and logical. For example, if PWMing your fuel pump is an idea you guys came up with, run an aux output near the area you would put your relay. Or if you have an extra AV input for your ECU harness, the logical place (in my opinion) to run it is by the intake being that that's where most of the sensors are already and is a likely place for future expansion.

Doing this, I also create extensions to avoid having a 3' long coil of wire. So I just run a DTM-P to a DTM-S for a few feet so I can simply expand the length if where I need it to go to is simply not long enough (this would be the case for a potted sensor or sensor with flying leads).

Another thing that can be done is to run extra inputs/outputs to a single large connector that you use to plugin an extra expansion harness to. What I did last year was ran 6 AVs, ground, and +5V into an 8 pin DTM connector. From there I created a simple plugin harness with long extensions, that way you can plugin sensors into the harness where ever they are on the car. The only purpose of this harness was to be used for testing when we ran tyre temperature sensors, strain gauges, etc... sensors that we would not normally run at comp. Doing this allowed me to eliminated a lot of extra wiring (the 8 pin connector was zip tied cleanly to a tube) and only took a few minutes to plug it in and get it hooked up and ready for testing.

As far as documentation goes, start off with this:
http://www.motec.com/filedownload.ph...pdf?docid=2708

MoTeC has a lot of great documentation (more can be found on their website) and they even have a lot of webinars that should further explain some of the setup and tuning details. As far as the video goes that I mentioned I have, I will have to get to that tomorrow.

And if any of my explanations are a bit confusing, just point them out and I can make some drawings, explain them more clearly, or take pictures of my harness (being removed from the 2013 car tomorrow as it will also be used on the 2014 car).

http://www.youtube.com/watch?v=E4mBO...ature=youtu.be

I'm hoping to have better information presented than that soon. Taking 2.5 labs was not a good idea in my interest of time. So forgive my delay in getting this upload. I'll have other stuff for you soon.

Hey Dylan, sorry for the late reply. Like you said, performing the ref/sync capture was simple. Took us about 15 minutes. Your video was also a big help in understanding how to set everything up and interpreting the ref/sync capture data. Hope you're able to make some more very soon.

For the Hall effect sensor, you said that you can select which one is the rising or falling edge. Do I choose the edge that lines up with the zero on the ref signal?

Also, the start file I downloaded has a lofted map. Is there an advantage to using this map over the flat map you started with in the video?

We tested our ecu last week with the new intake. We were delayed a bit due to fuel leaking from the rail. We didn't get the engine to run yet but found out some things. We forgot to set the firing order in the Motec software. The lambda seems to work (I'm getting about 1.4+ with the engine off) but when I try to set it up for Quick Lambda mode it starts kicking out errors C-5 or C-6. Gotta double check the wiring there. Ignition timing might be off as well, since we just guessed at our calculations with the crip.

Quick lambda is a nice feature in theory, but rarely as useful as you might imagine. The only time I've found it very useful is on a load dyno where you can very tightly control the rpm and load on the engine. Transients or not being fairly close to dead center on a cell will not generally yield you great results. Get used to downloading the logs and looking at what was happening in i2. This is where the magic happens.

If setting the CRIP was easy for you, then so should checking the timing with a timing light. Use the "test advance" feature in the ignition portion of the software to lock in the advance (follow the instructions). It's the last step in setting up the ref/sync stuff, and shouldn't be avoided. Also, it's wise to double check it any time you rebuild and/or swap engines. Variations can either point to assembly errors or other mechanical issues. Never assume it's correct, it only takes a few seconds to confirm! Happy timing!

I second what Kirk says about quick lambda. Even though we had an engine load dyno that was able to control RPM, we didn't think it safe to have it sitting at certain load points for extended periods (over boosting etc.). Even if you are N/A, transients and throttle response are where it's at, and for that you want i2.

Been a while since my last update. We started the engine and the idling is rough.