Interested in HID's and Options

[cyb593]

I was looking at ddmhid and i see on the site they have like 5 different kits. I was thinking about the bixenon kit. Is this the right kit or does it matter? Which number for color is the brightest or does it not matter? Should i upgrade to 55w? What about the relay harness/LBF modules? Also can i use the same balasts for high beams too? Sorry i am new to HID's and anything you can tell me will help me lots.

[Galcobar]

Some good information and some not necessarily accurate information in this thread.

Start with the basics: types of housings and reflectors.

There is your basic parabolic reflector (smooth reflective surface, often hemispherical). These are typically paired with a glass lens which shapes the reflected light. This is the oldest and cheapest design to produce. Poor quality or throwaway designs use thicker glass for the lens, which leads to less light on the road. This is the source of much of the improvement people report when switching from sealed beam headlights to permanent housings.

Then you have the complex reflector. In this design, which is what many people refer to as "crystal clear," the glass front is clear and plays no role in shaping the beam pattern. In this case the interior reflector is multi-faceted, thus the term "complex" reflector. Without computers these reflectors were too difficult to design, so they are notably newer but can fit into smaller spaces than the older parabolic design. These are vulnerable to poor reflector design. However, the clear front glass allows more light to pass through, so when properly executed they are more efficient than the parabolic design.

The best option, so far, is a projector module design. These modules use the thinnest front glass and capture more of the light produced by the bulb, making them the most efficient design. This is why many HID systems use projector modules.

To be clear, not all HID systems use projectors, and not all cars with projectors have HID. The Nissan Altima 2.5 SE used a complex reflector housing with HID bulbs, for example, and projector headlights were commercially available in the 1960s, long before HID was developed. They are typically used together for the premium look and superior performance of each system.

Something else to keep in mind is that the design of the housing depends on the bulb type. A different reflector shape, even if the same basic type of housing is used, applies to each bulb. Halogen bulbs have glowing filaments, HID have no filaments at all. You cannot properly use a housing meant for a halogen bulb to hold an HID system. This is a primary reason why conversions are illegal.

Now, specific to this thread: most of the people here are dealing with North American cars. These cars came with headlights which adhered to America's DOT regulations. DOT rules were written in the 1950s, for parabolic reflectors and cities with minimal lighting. The DOT beam pattern is designed to illuminate overhead signs. In short, they are obsolete. Moving from a headlight which uses the DOT-mandated beam pattern to one which uses the European-spec beam pattern is a vast improvement, even when they are the same basic parabolic design. The lenses are an upgrade.

This is the balance. Complex reflectors may give you more light output over an older parabolic design. But the beam pattern is what determines how much of that light is useful. Pulling numbers from the air, let's say from the same bulb a complex reflector outputs 2000 lumens, while a parabolic reflector allows 1800. However, the complex reflector is a DOT design which only puts 50% of that light on the road. The parabolic housing puts 65% of the light on the road. Useful light is 1000 lumens for the complex versus 1170 for the parabolic. Quality old tech usually wins over poorly executed new tech.

A key point for North Americans is that Japanese, UK and several other countries' beam patterns are reversed and using their projectors will blind incoming drivers. The modern beam pattern has a flat cutoff with an kink up to illuminate signs at the side of the road, like so: ____/. Drive on the wrong side and that kink is now illuminating oncoming drivers. E-code lenses use the same sharp cutoff, but are meant for driving on the right side of the road, as we do in North America. JDM projectors might give you a sharp cutoff, but it's still not a suitable beam pattern.

The glare seen with factory HID systems is rarely the factory's fault. The sharp cutoff required to make these bright lights safe for road use demands a different procedure to correctly aim them. A lot of people, mechanics included, don't realize this and aim the headlights after bulb replacements the same way they aim halogen headlights which conform to the DOT beam pattern, which is to say they aim them too high.

Sylvania Silverstars are a tinted lightbulb. This means they produce less useful light than their non-tinted counterparts. The source of the Sylvania Silverstar is the Osram Silverstar (Osram is Sylvania's European parent company). The Silverstars and their Philips VisionPlus counterparts are ultra-high efficiency bulbs, producing 50 per cent more light at the cost of durability -- standard halogens last for about 850 hours, ultra-high efficiency bulbs are expected to last about 150 hours. The tint on the Sylvania Silverstars cuts the light output from 150 per cent of a standard halogen to 110 per cent.

There are bulbs which produce even more light, but with decreasing bulb life. Going the other direction, high efficiency bulbs such as the Osram Super, Sylvania XV or Philips Premium produce 30 per cent more light than a standard halogen and last as long or longer.

That blue tint also decreases visibility in other ways. Lower colour temperatures (measured in Kelvins) are better for night driving. Our eyes use two different types of light sensors, colour-sensitive cones for bright situations and rods for low light situations. There are 120 million rods compared to 7 million cones, and rods are about 1000 times as sensitive as cones.

If our eyes have adapted to the dark and are relying on the rods to see, blue light is glaring. If our eyes then adjust to the blue light, we switch from rods to cones and lose night vision, producing a tunnel effect where you can't see outside of your headlights' direct illumination. Peripheral vision and motion detection is far better with rods activated. Red and yellow light, unless it's quite bright, don't activate the cones.

Atmospheric conditions are another consideration with high colour temperatures. The sky is blue and opaque because blue light is scattered by water. In rain, fog or snow, blue headlights will bounce back, creating a blinding wall of light ahead of you. Red and yellow light, because of their longer wavelengths, penetrate the water or mist and let you see the road ahead. This is why fog lights are often yellow.

My advice: get a good-quality housing with a proper E-code lens. Cibie is the best. Then pair it with a high efficiency bulb. You'll get more light, properly shaped.

This post has been edited by Galcobar: Aug 31, 2012 - 5:04 PM

[Syaoran]

My advice: get a good-quality housing with a proper E-code lens. Cibie is the best. Then pair it with a high efficiency bulb. You'll get more light, properly shaped.

Sadly Cibie makes nothing for the Celica.