For those sporting JDM headlights I thought I'd show a comparison of different bulb options available. The normal bulb for the JDM headlight is a halogen 3ZC bulb. A very short stubby one at that. For the last bunch of years those that decided to install a rebased HID kit opted to use an H3 HID kit. The H3 HID bulb is considerably longer than the halogen but was the closest thing available (at the time) that would fit into the base of the JDM headlight projector. I use that term "fit" loosely as it wasn't the most perfect fit. The base of the H3C Halogen bulb has two cut-aways to the base of it. One is square and the other rounded. The H3 HID bulb has the same cut-aways but not done well enough for the bulb to "easily" sit flush within the base of the projector. I'm not sure if others have experienced this, but getting an H3 HID bulb to sit square and flush in the projector base was a chore. VVME now have an H3C HID kit intended for use in headlights. In the pics below is the VVME 55W AC H3C 4300k HID Kit. From left to right; Halogen H3C | HID H3C | HID H3 Although it's hard to show in the pics, the H3C HID is ~ 1mm to 2mm shorter from base to top of bulb than the H3 HID bulb. On closer inspection, the base cut-aways for the H3C HID is more pronounced than the H3 HID and for the most part a perfect match to the base of the Halogen H3C. As well, there is an obvious ceramic mount between the bulb and base of the H3C HID. I can only assume that there's a ceramic base for the H3 HID but it's enclosed withing the black plastic below the mounting base. There's a noticeable thickness difference to the black plastic below the mounting bses of those 2 HID bulbs. I anticipate that fitting this H3C HID bulb will be much easier than the H3 HID bulb. I also anticipate (hoping) that since the glass globe portion of the H3C HID bulb is stubbier than that of the H3 HID bulb, it may also deliver a better beam pattern. I believe that those of us who already use H3 HID bulbs have observed that there's an extra amount of light/beam bleed-through than using halogen bulbs. I can only surmize it's due to the positioning and size of the H3 HID bulb in relation to the optics within the projector itself. The H3C's smaller glass globe part should reduce that bleed-through being that it's glass globe part is closer in size to that of the oem H3 halogen bulb. I'll post up my results on this after install.
You can also buy these globe types in adjustable form. Allowing you to fine tune the focal point of where the light emits from the different bulbs types, against the reflector. This will stop the light show for oncoming traffic which is common for hid installs where the headlights haven't been readjusted to compensate, and will allow you to maximize the projector better with the better quality light.
not sure about the HID's but the standard filament on a normal globe is the critical point to measure, not the overall globe length, assuming that the case is similar with the HID physical size is not as important as the location of the filament in respect to the reflector of the light housing. this gives the light beam its spread and angle, if you look at an old dual filament headlight globe you will see the 2 filaments at different locations this is what changes the angle of your hi/low beams the same happens when you change globe types with different filament locations. As stated earlier the globes location needs to be adjusted if its not correct for your head light to stop oncoming cars from being blinded.
Pretty much what I was getting at. However you've explained it better. Thankyou. iPhones suck for writing novels. I usually draw pictures for my customers when explaining this.
