So, after trying out a LED headlight bulb that will work with the weak light coil in the HPI CDI it was bright but only glowed bright because the light went straight out the front and not into the reflector.
This is a stock headlight at night-
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=DSCF0620.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/DSCF0620.jpg" border="0" alt="Pinto Headlight at night"></a>!
This is what a 5W LED looks like at night-
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=DSCF0623.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/DSCF0623.jpg" border="0" alt="LED Headlight at night"></a>!
As you can see the LED is bright but no beam, and the stock light is dim but all beam.
Side by side durring the day they look like this-
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=DSCF0618-2.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/DSCF0618-2.jpg" border="0" alt="Headlights - led vs bulb"></a>!
I found a wedge base bulb that has 15 LEDs that are arranged to throw light radially as opposed to straight out the front (3 at the tip + 3 X 4 sides).
I used a burnt out LED bulb for the 1158 socket base and the old material from the dead bulb to fit the wegde base bulb into the 1158 base and soldered the contacts and glued the bulb into place.
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=newbulb.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/newbulb.jpg" border="0" alt="New LED Bulb"></a>!
It worked, but flickered really bad. That was because the new bulb is only an array of LEDs and DC by nature, and magneto coil systems produce AC current. So I added a full-wave bridge rectifier to it. That made it twice as bright but the flicker was twice as fast. I added a 100uf capacitor and that took the flicker out and it works awesome.
Here are the components-
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=components.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/components.jpg" border="0" alt="Headlight components"></a>!
The capacitor is on the left, the bulb in the center, above and below the bulb are the wires that make a splice connection for the capacitor, and on the right is the rectifier. The rectifier converts the AC current generated by the coil into DC current. The capacitor is a filter that smoothes out the fluctuation of the current (the flicker in the light). I used barrel connectors on the capacitor so I could try out different capacitor values. I found that 100uf gives the fastest response with the least drain on the circuit.
Here's what the mess looks like hooked up-
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=allconnected.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/allconnected.jpg" border="0" alt="Headlight all connected"></a>!
I'll get a pic of the beam it throws at night when I can, but these should give you an idea. The first one is of the bulb and stuff installed in the headlight bucket. The other two are of it running from two different angles.
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=Headlighoff.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/Headlighoff.jpg" border="0" alt="Headlight off"></a>!
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=Headlighton.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/Headlighton.jpg" border="0" alt="Headlight on"></a>!
!<a href="http://s651.photobucket.com/albums/uu237/samsporter/?action=view¤t=Headlightonfromabove.jpg" target="_blank"><img src="http://i651.photobucket.com/albums/uu237/samsporter/Headlightonfromabove.jpg" border="0" alt="Headlight on from above"></a>!
When I first put it together and tried it out, the bulb was protruding (sticking out) badly and made a dark spot in the center of the beam.
It wasn't easy but I moved the bulb deeper into the socket and that focused it perfectly.
This new design is really impressive at night. The light is a cold white light but it lights up the road incredibly.
I used the idea that a regular bulb isn't really that bright, but it emits light all around it that is captured and focused by the parabolic mirror of the headlight. So I went with an LED bulb that does the same and the results are even better.