HID kits- in depth...

[TheMAN]

better yes, but still BAD

to get safe results, you must replace the housings completely with the j-spec HID ones

oh ok. so would my headlight be better for a HID upgrade compaired to the DOT beam pattern???

 

[TheMAN]

here's a pic of what a real HID beam pattern should look like... from a European spec 2000 Audi S4 housing (UNECE r98 right hand traffic compliant) using D2S balasts:

very even light distribution, not big blobs of light

and the US-spec DOT VOL HID beam pattern of a 2000 Audi S4:

much weaker lighting

pics found from this Audi world how-to:
http://www.audiworld.com/tech/ext30.shtml



and for the non-believers of why j-spec headlights shouldn't be used and think all headlights emit a symetrical "blob" of light:

picture from PS13 Silvia with reflector type housing with HID "retrofit"

 

[twilightprotege]

good comparison, thanks

 

[kcbhiw]

Excellent article. Having personally studied lighting and its associated attributes, Edwin is absolutely correct.

As an informational post:

Just a couple notes, the "ballast" is actually the control module, a solid state electronic device in the case of automotive HID lighting.

We know halogen bulbs uses a filament. We also know xenon bulbs have no filaments are filled with as the name implies, xenon and other trace gases. Ok, so when a xenon bulb is turned "on", the gas gets electrically charged, but based on phsyics (which I basically know nothing about), the electrically excited xenon gases want to move away. This is stopped by the glass balast. So the effect that we get is an arc that starts from one end of the balast, curves upward, then back down at the other end.

The "glass ballast" that is referenced here is known as the "arc tube". As accurately described here, the arc tube is essentially a quartz tube (pea sized) with an electrode at either end. An electric arc, once established, excites the gasses within (typically comprised of xenon, mercury, halide salts, and other inert gasses).

The technology of the automotive HID lighting is nearly identical to that used in street lights, sports arena lighting, parking lot lighting, and similar to fluoresecnt lighting; all gas/arc discharge lighting. (metal halide, mercury vapor, high pressure sodium)

A halogen bulb just glows in a cylindrical shape due to the filament and depending on how the filament is placed in the balast determines the geometric position/"center" of the light.

Correct. Not only is the LCL (light center length) different between the halogen and HID lamps, but the orientation of the actual light source is different resulting in a misalignment with the reflective surfaces/elements within the headlight housing.

 

[tttP5]

very good job !
u make it easy to understand

 

[andyfatsax]

Can't wait to install my HID kit. Should be here Friday!

 

[murda79]

Don't know if this helps but I did a retrofit from an Audi A4 and are using d2r bulbs which are designed for reflective housings. The beam pattern is the same as it was with my halogens, just much brighter. The strip on the bulbs really is effective in reducing glare being thrown upwards.

 

[changedman]

back from october!

 

[Brian MP5T]

Great Write Up!

 

[THEGOLDPRO]

Great Write Up!

almost there man

 

[Brian MP5T]

3,984!

 

[pb4ugoout]

well, i've had people drive my car behind me and in the other lane past me while driving their car so that i could see if my lights were too bright or if they glared. and i really don't give a s*** about those laws. in the 10 or so different ways i looked at the lights i never once saw them as being too bright or had to look away. i've also gotten other peoples opinions and no one has said anything bad. so i'm not gonna worry or change anything.