| Author | Message | ||
     Wolffone2000 |
Has anyone considered installing the MSD (or similar) dual coil setup? I have been informed by some old-school Harley guys the dual coils will produce much more power and smooth the idle out much more. The single coil design was cost driven in origin. | ||
| Thunderbox |
The voltage with dual coils will not be any higher than with a single coil. The reason for this is the voltage created in the secondary windings of the coil will only go as high as it needs to go to jump the gap at the plug and then it jumps. If everything else remains the same the spark will not be any hotter or of a higher voltage even if they say it can produce 2000000v. Thats just the potential. I guarantee you will not notice any difference. If you had an engine running at 15000rpm and you could feed the 2 coils separately you would be able to increase the dwell time and it may be of benifit in that case at very high RPMs. If Buell could lower emmissions and make their engine run better by adding dual coils the would. Forget the dual coil senario. Wasted money. | ||
| Bomber |
on the other hand, wiht Dual Coils, both you and a buddy would be able to walk ten paces, and throw em at each other | ||
| Lorazepam |
You could also say "my coil's bigger than yours." | ||
| Wolffone2000 |
Actually, the point I was making, and didn't really clarify, is the timing of the spark, not so much as the intensity. If the coil is firing for both cylinders at the same time, then ignition is happening when it isn't necessary on the other cylinder. Maybe I misunderstood, but it seemed to make sense. | ||
| Bomber |
there was a write up of single fire vs dual fire ignitions in the KV -- not much measurable performance difference, if I'm remembering correctly | ||
| Lorazepam |
wasted spark ignition is what that is called. Doesnt make much difference, really. | ||
| Thunderbox |
That is correct wasted spark. Has been in use since at least 1966 as I had a 1966 Honda CB160 used wasted spark ignition. But yes there is a dyno chart on this site in the Knowledge vault. Shows no difference in Torque or HP of any significance. | ||
| Opto |
I think the XB's already have dual coils with non-wasted spark, both coils built into the same housing. | ||
| Firemanjim |
The dual coils comes in play with a single fire ignition set-up.I don't believe the XB's can do this as your ecm is the ignition box where the tuber/carbed bikes could swap module easily. There may be no dyno improvement but I can say from first hand experience on multiple Buells and HDs that it does smooth out the idle and low speed running.It eliminated the low speed spit/surge on my S-2. Run it on the racebike also as the new Dyna set-up is programmable and has a ignition retard feature for nitrous/turbo set-ups. |
