rusefi.com

Hello everyone!

I have been thinking about implementing a standalone ECU solution on an ICE for years now, but never grew enough courage to actually try it out. Well, I have now decided to take the first step by using rusEFI with the Core8 board to run my '04 Honda VTX1300C motorcycle. It has 52 degrees V-Twin engine with an uneven firing pattern (308 & 412 degrees) recently converted to EFI using some donor parts from a newer motorcycle and a custom wiring harness.

My goal is to run this engine on a sequential fuel injection/ignition. My starting point is figuring out trigger patterns in order to understand what I mechanical additions/modification may be needed on the bike. And on that note, I have a few questions I hope you guys can help me figure out.

1. What trigger setup do I need to run sequential injection/ignition on this particular engine layout? Do I need one crank wheel and one cam wheel per cylinder head? Or would one crank wheel and one cam wheel suffice?
2. How do I determine the optimal teeth count for the crank and/or camshaft(s) trigger wheels?
3. Does the diameter of the trigger wheels matter? And if so, what information do I need to make an informed decision?

One crank and one cam would do

MAP sensor could be used as cam on v-twin engines

Please consider donor parts for trigger wheel as well?

Please help me understand your suggestions. How would the MAP sensor be used instead of the cam trigger? Would the system look at a drop in pressure and conclude the engine is in the intake stroke? I think this is how the original Honda system works on the original VT1300 , and how it is actually working on mine. I wasn't sure I could replicate that with the rusEFI.

On the subject of crank trigger, how would I go about going getting a donor part? I have no idea whether I should go for a 36-1, 36-2, 62-1, or a 61-2 pattern, and more importantly, I do not know what information I need to make the right decision. How do I go about making a choice about trigger wheel size and tooth count?

Also, there is a matter of packing. I have two options at the moment: 1) modify the magneto (which has 12 teeth and is missing 3, I believe) to accommodate for a supported trigger wheel and use the original Honda sensor, 2) place a trigger wheel on the opposite side of the crank, on the timing cover side, and add a sensor there. Option 2 seems like the cheapest route to go at the moment.

Yes, that's how MAP is used for phase detection - your asymmetrical engine produces asymmetrical vacuum.

36-2 or 60-2 would be slight better than 36-1 or 60-1. Either would work just fine. As long as you use wheel from any vehicle you would be fine, just please do not attempt making your own.

Why would making a custom 60-2 wheel be a problem?