twinturbowagon

This thread is going to be split up into 2 sections. This first post will be a general headlight maintenance guide and the second will be a small build log on a headlight project I am working on which can be used as a reference for all maintenance items I discuss here.
The 996 chassis is on the doorstep of becoming 20 years old and as I am sure most of you know being enthusiasts that it is critical to properly maintain your 996 to keep it performing at it's best, the same thing can be applied to the headlights.

HEADLIGHT MAINTENANCE
Before getting into the specifics of this particular build I would like to cover some basic headlight maintenance items as it pertains to the 996 so you know what to expect, know what to look for, and know how to keep the headlights performing well. This is tailored around the facelifted xenon 996 headlights but the general concepts apply to most HID/Xenon headlights.

HOUSINGS: This is a "if it ain't broke don't fix it" item. If the housings are structurally sound with no holes, missing mounts, or major damages there is nothing to be worried about. Porsche headlights have a rather ingenious mounting solution where the headlight is slide into the fender and then small mounting pegs on the housing are locked into position with a clamping mechanism. These small mounting pegs on the housing can break off from the plastic becoming brittle and/or improper installation/removal. 3 of the 4 pegs are molded into the housing and the 4th by the washer nozzle can be replaced. In general if one peg is broken off the headlight can still be mounted securely since you still have 75% clamping power, if you are missing 2 then double check that the headlight doesn't wiggle when installed, if you are missing 3 or more seriously reflect on why this has happened.

LENSES: I see many 996 lenses suffering from haze and yellowing. This UV damage the 996s headlights are particularly vulnerable to it given how flat the lenses sit, they are essentially sunbathing all the time. One thing which is nice about this raked lens position is the lenses are less likely to take as many hard impacts from road debris and consequently should suffer less from pitting and rock chips. This combination of high UV damage and low lens abrasion means chances are good the lenses can be restored with great success. A proper lens restoration includes multi-stage sanding prior to polishing so a lot of the light surface blemishes (UV damage) will be removed, it is the deep chips and rouges from debris detailers can't remove. So chances are your lenses can look brand new or close to it with a proper multi-stage sanding + compounding + polishing restoration. Expect to pay $100-$150 to have the headlights lenses restored by a professional.

After you have the lenses looking like new it is time to protect them. There are 2 things to protect against: the sun (UV) and abrasion. There are some UV sealants like Opti-Lens which is great for UV but doesn't really address abrasion. Paint Protection Films (PPF) are continually evolving and the current offerings are really good with "self-healing" properties and UV protection so a quality PPF is what I recommend to keep your refreshed headlights looking sharp for a long time. The 996 lenses have rubber gaskets which wrap around the perimeter of the lens and seal against the fender when the lights are installed, they have some areas there the gasket is very thin and depending on their condition they can become brittle and break so if you have the headlights out of the car it is good just to visually inspect these to confirm their condition.

WIRING: The HID ballasts are mounted on the back of the headlight and there is some wiring running to them from the housing, this coating of these wires can become brittle and flake off over time so another item to visually inspect if given the opportunity, same goes for the wiring inside the headlight if you have the rear housing cover off and are replacing a bulb.

HID BULBS: Bulbs are a wear item and have a finite lifespan. Most HID bulbs are rated for ~2,000 hours and in many cases the bulbs will outlast the life of the car or at least the term an owner has it but it is important to understand the difference between "failure" and "sub optimal performance." The moment after a brand new bulb is ignited for the first time it slowly starts to fade, the more it's used the more it fades. Since bulbs use hours as a measure and cars use miles it can be hard to keep track of how much use your bulbs have received but if your headlights are seeing semi-frequent use a good rule of thumb is to replace the bulbs ~3 years. If you can't recall the last time yoru HID bulbs were replaced then chances are it has been 5+ years and if that's the case it is likely you can get a nice bump in light output (~+30%) by simply replacing your bulbs, if you are still on the factory supplied bulbs the it could be as much as 50%. Adding fresh HID bulbs is the most cost effective way to improve your headlight output. Spend the money on quality OEM bulbs from Philips and Osram, they will run $100-$200/pr which isn't cheap but it is money well spent as they perform better, last longer, and are more reliable than aftermarket options. Buy from a reliable source like The Retrofit Source. If you see $100 Philips bulbs for $20 on eBay they are fakes. The Osram CBIs are the best bang for your buck and my go-to.

HID BALLASTS: The big metal boxes mounted to the back of your headlights, these are what ignite and power the HID bulbs. The 996 comes equipped with Hella Gen 3 ballasts which are regarded as the best ever since they have a fast warm up time and are extremely reliable. OEM ballasts don't fade over time like a bulb, in rare cases a ballast might flicker or have sporadic function as it's dying but 90% of the time they either work or they don't and in most cases these built-like-a-tank ballasts work! These ballasts to have a trick up their sleeve, they can be "boosted." By swapping some internal components the output can be raised from 35w to 41w, 43w, 46w, 48, 50w, or 55w and the best part is the ballasts are not simply over driven but their efficiency is also increased so they can better handle the power. Think of this as turbocharging your ballast and not simply extracting power with an overly aggressive tune.

See attached for a guide I made on the process.

What's unique about this is 99% of OEM ballasts are 35w and there are 45w-55w HID ballasts available but they are aftermarket and will not offer the same reliability so these Hellas are very unique since you can get OEM quality/reliability with uprated power levels usually reserved for aftermarket, it's a win-win.

PROJECTORS: Arguably the most critical component of the headlights which can make the most dramatic impact on the light you see on the road. Even with the best HID bulb and the most powerful ballast, if your projector has a poor optical design it will be all for not. Thankfully the stock 996 projectors are "good" when in pristine condition but the chrome on the inside of the bowls (which reflect the light emitted from the bulb) can deteriorate over time. HID bulbs emit UV light as well as heat which can turn the chrome from a mirror-like finish into a hazey, blistered, or cracked finish. These blemishes rob light output and intensity takes takes a big hit. Most HID projectors are designed to have an intense pocket of light (the "hotspot") right in the middle at the top of the beam pattern which helps you see better down the road. Projectors which have a compromised chrome finish on their bowls will lose this intense hotspot and the light output is general will be "softer." I will have some pictures later in the thread showing this.

Once the chrome of the projector bowl is compromised the projector must be replaced to restore proper performance. This involved removing the headlight lens to gain access to the projector mounted inside, where opening the headlight is a labor intensive process which will cost you either time or money depending if you do it yourself or outsource it to a professional, with the headlight open this also opens the doors of opportunity to not only replace the projector but upgrade the unit. This is something I demonstrate below.

HEADLIGHT AIM: Last but certainly not least: the most critical, easiest to resolve, and most commonly overlooked element of headlight performance. Headlights aimed too high will be blinding oncoming traffic and headlights aimed too low will not be underperforming. Attached is a guide I made for the Tesla Model S but the method and concepts are applicable to the 996, 996 specific procedures are also below. Most of the general headlight aiming guides online recommend a 2" drop but given the lower ride height of the 996 compared to say a truck, crossover, or large sedan a 1" drop will allow slightly better light "throw" down the road without impeding oncoming traffic. Even if you think your headlights are aimed properly it is good to check, sometimes they can wander out of alignment, and you would be surprised how many headlights leave the factory improperly aimed.

Hopefully this guide is helpful! Seeing where you are driving at night is important!

Build log to follow shortly,
Cheers!
Evan