|Project Audi S4: Euro HID Headlight Housings
Not all upgrades have to be buried under the hood or the fenders to be effective. It's always nice when you find one that is as good looking as it is practical, and that is certainly the case with the European specification (also known as E-Code) S4 headlight upgrade.
Consistent with its European high performance automobile peers, the S4 comes with stock xenon headlights. These lights, sometimes referred to as HIDs (high intensity discharge), utilize a gas-discharge lamp which is electronically controlled. The arc unit in an HID contains a gas (mostly xenon, which is inert) that is ignited by high-voltage. The resulting arc produces about twice as much light as a comparable halogen headlight, making it ideal for roadway illumination. The spectrum of xenon light is also much closer to daylight than conventional halogen, giving it that sought-after light blue/white color.
While clearly high performing, the stock headlights in our Project S4 had serious drawbacks relative to their European counterparts. First, there is a difference between the North American and the Euro low beam projector lenses. The North American version uses a stepped lens which diffuses the light output, while the Euro lens is smooth and generates a sharper output. The North American unit also includes a restricting bulb "shade" behind the lens, limiting low beam output. Last but not least the North American headlights have orange corners which tend to ruin the clean, sleek line of the car when viewing the exterior from the front and side. Euro headlights, of course, utilize clear corners.
The justification for the upgrade, then, was twofold: 1) Safer, less tiring driving conditions based on the larger, brighter beam output and pattern; and 2) A clean, clear-corner look.
The Valeo Euro headlight upgrades sold by AWE Tuning smartly re-use the car's existing HID/Xenon bulbs and ballasts and all harnesses plug right in. This is a much cheaper solution than going with brand new HID bulbs, H7 bulbs, leveling motors/seals and ballast units - a cost savings of about $470.
Installation is definitely a DIY affair so long as you have the right tools, or more specifically tool. Even folks with comprehensive tool sets are probably going to need a trip to the hardware or locksmith/key store to buy a TORX T20 security bit which looks like most TORX bits only with small hole in the end. These types of bolts are used in so called "tamper proof" applications.
After removing the bolts which secure the headlight the next step is to slide the unit out and unclip the wiring connectors. The headlight can now be removed to a more suitable work location where it will be disassembled in order to move the required internal parts to the E-Codes.
The bulbs, ballast and aiming motor will all be removed from the North American spec headlight. This is a straightforward operation, requiring some attention not to touch the HID bulb and to not break anything as you take it out.
At this point attention is focused on the Euro headlights and repeating the same steps in reverse in order to install all of the components. The trickiest re-installation procedure is finessing the aiming motor stalk back into place, but with a little patience it will eventually snap in.
If you have chosen the city lighting option then there is a bit more additional wiring required in order to power the low intensity bulb. AWE includes all the required wires and splicing connector to tap into the existing power - a quick 5 minute operation.
After reinstalling the now Euro spec headlights into the car the only step that remains is to check and adjust the headlight aiming. Because the Euro lights are so much brighter it is recommended to aim them approximately 1.5" lower than the stock lights. The installation instructions include full details on both marking the height before starting the upgrade and then aligning the new E-Codes.
As stated in the introduction, the Euro headlight upgrade serves the dual purpose of being a safety and a cosmetic upgrade. With the easy-to-follow installation instructions it is also a very simple, do-it-yourself upgrade. The only drawback is the well-documented propensity for the stock Audi HID headlights to be stolen (or E-Codes - it would be very hard for a thief to tell the difference). For obvious reasons we recommend common sense about where and when the vehicle is left unattended, particularly if you've invested hard earned cash in the form of upgrades.
Up Next . . .
One more major upgrade for Project S4 and then coverage on the new B6 S4 project cars begins in earnest.