Hello and thanks! Think I have this figured out but wish to verify. Application is a 2-cyl. Triumph motorcycle, 750 cc and max. rpm 7200 or so.... The bike has a 360 degree crank, IE: both pistons move together (like a single) but one on compression, other on exhaust. Currently running a Boyer-Brandson analog ignition. Basically, it's a little box w/ fixed advance curve and triggers by cam mounted rotor with 2 pick-ups. Coils wired in series so fires both plugs every revolution (wasted spark.) I wish to MegaJolt-E this thing!
So, can I just use "coil-a" output so MJ would only fire on 360 degree intervals where I need it? Leave the other one unhooked ok?
If so, what are the odds I can use existing coils on bike? They are 2, dual tower coils (dual plug head) 2.2 ohm primary, 14K secondary resistance. Should I parallel them to give me 1.1 Ohm? Close enough to .5 Ohm? This means like 11 amps... Also of note is I run total loss battery, so high amps gives me worry. If I left in series, would EDIS mind the 4.4 Ohms? I would think there is plenty of time to charge coils with the relatively low rpm ceiling.
Your time and thoughts greatly appreciated!
Cheers, Jason
Twin Cylinder Motorcycle Application- Questions....
Moderators: JeffC, rdoherty, stieg, brentp
Hi, Thanks for the inquiry.
Remember the number of amps is a function of RPM and duty cycle of the coil. The coil isn't 'on' all the time, but only during the dwell period. the total current draw will probably be close to what you have right now.
For single cylinder applications like you describe you would just ignore one of the outputs, yes.
Would have to learn more about your coils before we can comment on them. how many leads drive the coil? what's the wiring like?
Remember the number of amps is a function of RPM and duty cycle of the coil. The coil isn't 'on' all the time, but only during the dwell period. the total current draw will probably be close to what you have right now.
For single cylinder applications like you describe you would just ignore one of the outputs, yes.
Would have to learn more about your coils before we can comment on them. how many leads drive the coil? what's the wiring like?
Thanks Brent!
See: http://www.dynaonline.com/skins/product ... yna_Coils/
for information on the coils (can't load picture.) These are DC4-1 units. Coils have an in and out for 12 vt(+) and (-) and two towers (HT) for the plugs. That's it! The primary resistance is 2.2 Ohm, secondary 12-14K Ohm. 12 volts from the Boyer ignition is sent to one pole on a coil (doesn't really matter which one), and returns to Boyer from the other. In my case, it goes through a second coil serially, then back to ignition. Just a simple coil really. Using just half the coil outputs from the edis, I thought to wire from pin 8 in connector, through both my coils, and back to pin 10. Pin 12 not used.
I'm sorry, I'll learn how to post a picture of my diagram soon. What I don't know is how the edis will like "seeing" either 4.4 or 1.1 ohms, as it's used to seeing only 0.5...
More to ponder....I have a toothed belt primary drive that 'lo and behold' has 36 teeth on the crank pully! Now I don't have to make a wheel! So, I purchased a tiny Red Lion VR sensor to suit. The idea is that a grind a short section of one tooth off the end. Think of your trigger wheel only 2" thick. So, how much clearance should I give the VR sensor you think? 3x's diameter of sensor enough?
Thanks again for your efforts and assistance-[/img]
See: http://www.dynaonline.com/skins/product ... yna_Coils/
for information on the coils (can't load picture.) These are DC4-1 units. Coils have an in and out for 12 vt(+) and (-) and two towers (HT) for the plugs. That's it! The primary resistance is 2.2 Ohm, secondary 12-14K Ohm. 12 volts from the Boyer ignition is sent to one pole on a coil (doesn't really matter which one), and returns to Boyer from the other. In my case, it goes through a second coil serially, then back to ignition. Just a simple coil really. Using just half the coil outputs from the edis, I thought to wire from pin 8 in connector, through both my coils, and back to pin 10. Pin 12 not used.
I'm sorry, I'll learn how to post a picture of my diagram soon. What I don't know is how the edis will like "seeing" either 4.4 or 1.1 ohms, as it's used to seeing only 0.5...
More to ponder....I have a toothed belt primary drive that 'lo and behold' has 36 teeth on the crank pully! Now I don't have to make a wheel! So, I purchased a tiny Red Lion VR sensor to suit. The idea is that a grind a short section of one tooth off the end. Think of your trigger wheel only 2" thick. So, how much clearance should I give the VR sensor you think? 3x's diameter of sensor enough?
Thanks again for your efforts and assistance-[/img]
I've researched quite a bit concerning the VR sensor (Bowling - Grippo, et Al.) Sensor tip size relative to tooth width/length/depth, etc.. Also rotational speed is very important. Forgot the box at home today but will post model specifics. Close to sensor! Yes.... now another potential problem. These old Brit-bikes (no offense lads) weren't made with the tightest tolerances. I think run-out of the crank might be quite a few thou! Just going to have to try it out.
Thanks Toenee, yes- head has dual plugs. Standard ignition timing, full advance is 38 degress. I run around 31/32 degress with the extra plug. Does make a difference!
Thanks Toenee, yes- head has dual plugs. Standard ignition timing, full advance is 38 degress. I run around 31/32 degress with the extra plug. Does make a difference!
http://www.redlion.net/Products/Digital ... ckups.html
See above link for sensor info. Good for all to see as this may give other choices in difficult applications. I selected the MP37TA00.
Cheers!
See above link for sensor info. Good for all to see as this may give other choices in difficult applications. I selected the MP37TA00.
Cheers!