'04 Honda VTX1300 V-Twin Motorcycle

[ccr0ss]

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?

[AndreyB]

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?

[ccr0ss]

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.

[AndreyB]

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.

[ccr0ss]

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