stanton
09-14-2003, 05:57 PM
As headlights are more sophisticated now than the blob of light they used to be, designers are able to direct light on the road and sides without blinding oncoming drivers. Since traffic in Japan is on the left side of the road, the beam pattern used there is directed low directly in front and to the right of the car, and allowed to raise a bit to the left of the car, where traffic shouldn’t be. Without “intelligent” headlights, this is about as good as you get from a static light pattern.
When one brings lights from Australia, Asia, UK to Europe or the Americas, the beam pattern is opposite of desired for the traffic on the other side of the road. Cars designed to drive on the right side of the road are called “left-hand-drive” (LHD) because of where the driver sits. Below are some details on what I did to convert JDM STi HID headlights from RHD to LHD. I believe it’s the same for JDM, Australia, UK halogen lights. Comments are surely welcome.
The 2001/2002 STi headlights from Europe and Japan markets use a “projector” lens for low-beam light. The bulb (capsule if HID) is placed “outside” the focal point of a parabolic reflector. Instead of parallel light rays from the parabolic reflector, the light is focused onto a mask used to determine where the shadows should be. A convex lens is then used to focus the light to a more coherent beam. The resultant light is an evenly distributed flood effect with dark areas designated by the mask shape.
http://faq.auto.light.tripod.com/projector-unit.htm
The mask used in JDM lights masks light more on the right, with a rising cut-off to the left. To use these lights in a LHD car would mean either aiming the headlights very low or blinding oncoming drivers.
To convert these JDM lights to LHD, one has to open the headlight and replace the mask with the appropriate one. Since I didn’t have a LHD mask with me, and didn’t know where to get one, I reshaped the RHD mask to have a rising cut-off to the right.
*NOTE* - I only noticed this after the light was all assembled and installed, but there is noticeable glare from light reflecting off the bottom of the chrome bezel in front of the lens. It’s noticeable from a distance while standing in front of the car and doesn’t really provide useful light, but would annoy oncoming traffic. I don’t know if this is related to the modification, or if it’s common with JDM HIDs. I haven’t confirmed this with any owners yet. If you know what I’m talking about I’d like to hear from you. For now have a small piece of tape on the outside front lens of the headlight over the lowest part of the bezel.
The headlight is held together with black rubbery adhesive, plastic locking clips, and a few screws. There instruction around on boards for more details about splitting the USDM headlight to removed the orange blinker cover, or paint chrome inside. These open the same way. The light must be placed in an oven to soften the adhesive before it can be split open. First, I didn’t want to damage any more of the light than I had to, so I removed all the light bulbs and sockets (this also lets oven heat get into the light faster). Remember to not touch halogen or HID bulbs.
I removed the 2 screws helping hold the light together. Work on one light at a time. Be prepared to work on the light after removing it from the oven. The work area and your hands should be very clean. Have a heat-resistant place to set it down. Have a screwdriver handy for separating it, and a utility knife to cut strings of rubber adhesive while separating the shell.
I used 200 F and 20 minutes to heat the headlight. Others have used higher temperatures and shorter time, but I wanted to be “safer”. Oven mitts are a must when handling the hot light. Immediately after removing the light from the oven, work with the screwdriver to “unclip” the little plastic locks and slowly separate the shell. As you separate the halves, the rubber adhesive will be stringy. Use the knife to cut the strings while they’re short, and avoid letting any adhesive getting on the reflectors, lens, or trim inside the light.
When one brings lights from Australia, Asia, UK to Europe or the Americas, the beam pattern is opposite of desired for the traffic on the other side of the road. Cars designed to drive on the right side of the road are called “left-hand-drive” (LHD) because of where the driver sits. Below are some details on what I did to convert JDM STi HID headlights from RHD to LHD. I believe it’s the same for JDM, Australia, UK halogen lights. Comments are surely welcome.
The 2001/2002 STi headlights from Europe and Japan markets use a “projector” lens for low-beam light. The bulb (capsule if HID) is placed “outside” the focal point of a parabolic reflector. Instead of parallel light rays from the parabolic reflector, the light is focused onto a mask used to determine where the shadows should be. A convex lens is then used to focus the light to a more coherent beam. The resultant light is an evenly distributed flood effect with dark areas designated by the mask shape.
http://faq.auto.light.tripod.com/projector-unit.htm
The mask used in JDM lights masks light more on the right, with a rising cut-off to the left. To use these lights in a LHD car would mean either aiming the headlights very low or blinding oncoming drivers.
To convert these JDM lights to LHD, one has to open the headlight and replace the mask with the appropriate one. Since I didn’t have a LHD mask with me, and didn’t know where to get one, I reshaped the RHD mask to have a rising cut-off to the right.
*NOTE* - I only noticed this after the light was all assembled and installed, but there is noticeable glare from light reflecting off the bottom of the chrome bezel in front of the lens. It’s noticeable from a distance while standing in front of the car and doesn’t really provide useful light, but would annoy oncoming traffic. I don’t know if this is related to the modification, or if it’s common with JDM HIDs. I haven’t confirmed this with any owners yet. If you know what I’m talking about I’d like to hear from you. For now have a small piece of tape on the outside front lens of the headlight over the lowest part of the bezel.
The headlight is held together with black rubbery adhesive, plastic locking clips, and a few screws. There instruction around on boards for more details about splitting the USDM headlight to removed the orange blinker cover, or paint chrome inside. These open the same way. The light must be placed in an oven to soften the adhesive before it can be split open. First, I didn’t want to damage any more of the light than I had to, so I removed all the light bulbs and sockets (this also lets oven heat get into the light faster). Remember to not touch halogen or HID bulbs.
I removed the 2 screws helping hold the light together. Work on one light at a time. Be prepared to work on the light after removing it from the oven. The work area and your hands should be very clean. Have a heat-resistant place to set it down. Have a screwdriver handy for separating it, and a utility knife to cut strings of rubber adhesive while separating the shell.
I used 200 F and 20 minutes to heat the headlight. Others have used higher temperatures and shorter time, but I wanted to be “safer”. Oven mitts are a must when handling the hot light. Immediately after removing the light from the oven, work with the screwdriver to “unclip” the little plastic locks and slowly separate the shell. As you separate the halves, the rubber adhesive will be stringy. Use the knife to cut the strings while they’re short, and avoid letting any adhesive getting on the reflectors, lens, or trim inside the light.