HID hi-beam only upgrade

[Octavian]

By the way, for the 5V DRL on high beams I use a nice little, 95% efficient switching regulator plus a protecting 9A 90SQ045 Schottky diode.
The protecting diode generates as much heat as the regulator... I also put a 4.3V Zener diode on the cluster high beam light, so when it gets dark and I have DRLs on I start noticing it, and of course it works just fine when high beams are on. The cluster lights on the Superb are LEDs, that's why I got away with such a cheap trick.

Of course, here in Europe everyone shuns DRLs on high beams, and I personally think this is the best way to implement them, provided you get the voltage right. OK, an even better way is to use dedicated luxeon LEDs with lenses for this, but that is difficult in stock headlight housings.

A little off-topic, I know

Edit: in this post the cluster means speedo/rev meters and so on, not the headlight housing

 

[dieseldorf]

I posed my question to Daniel. Here's how he replied:

Thinking of converting to HID?

So you've read about HID headlamps and have it in mind to convert your car. A few mouse clicks on the web, and you've found a couple of outfits offering to sell you a "conversion" that will fit any car with a given type of halogen bulb. STOP! Put away that credit card.


An HID kit consists of HID ballasts and bulbs for "retrofitting" into a halogen headlamp. Often, these products are advertised using the name of a reputable lighting company ("Real Philips kit! Real Osram kit! Real Hella kit!") to try to give the potential buyer the illusion of legitimacy. Fact: While some of the components in these kits are sometimes manufactured by the companies mentioned, the components aren't being put to their designed or intended use. Reputable companies like Philips, Osram, Hella, etc. NEVER endorse this kind of "retrofit" usage of their products.

Halogen headlamps and HID headlamps require very different optics to produce a safe and effective—not to mention legal—beam pattern. How come? Because of the very different characteristics of the two kinds of light source.

A halogen bulb has a cylindrical light source: the glowing filament. The space immediately surrounding the cylinder of light is completely dark, and so the sharpest contrast between bright and dark is along the edges of the cylinder of light. The ends of the filament cylinder fade from bright to dark. An HID bulb, on the other hand, has a crescent-shaped light source -- the arc. It's crescent-shaped because as it passes through the space between the two electrodes, its heat causes it to try to rise. The space immediately surrounding the crescent of light glows in layers...the closer to the crescent of light, the brighter the glow. The ends of the arc crescent are the brightest points, and immediately beyond these points is completely dark, so the sharpest contrast between bright and dark is at the ends of the crescent of light.


This diagram shows the very different characteristics of the filament vs. the arc:

When designing the optics (lens and/or reflector) for a lamp, the characteristics of the light source are *the* driving factor around which everything else must be engineered. If you go and change the light source, you've done the equivalent of putting on somebody else's eyeglasses: You can probably make them fit on your face OK, but you won't see properly.

Now, what about those "retrofit" jobs in which the beam cutoff still appears sharp? Don't be fooled; it's an error to judge a beam pattern solely by its cutoff. In many lamps, especially the projector types, the cutoff will remain the same regardless of what light source is behind it. Halogen bulb, HID capsule, cigarette lighter, firefly, hold it up to the sun—whatever. That's because of the way a projector lamp works. The cutoff is simply the projected image of a piece of metal running side-to-side behind the lens. Where the optics come in is in distributing the light under the cutoff. And, as with all other automotive lamps (and, in fact, all optical instruments), the optics are calculated based not just on where the light source is within the lamp (focal length) but also the specific photometric characteristics of the light source...which parts of it are brighter, which parts of it are darker, where the boundaries of the light source are, whether the boundaries are sharp or fuzzy, the shape of the light source, and so forth.

As if the optical mismatch weren't reason enough to drop the idea of "retrofitting" an HID bulb where a halogen one belongs—and it is reason enough!—there are even more reasons why not to do it. Here are some of them:

The only available arc capsules have a longitudinal arc (arc path runs front to back) on the axis of the bulb, but many popular halogen headlamp bulbs, such as 9004, 9007, H3 and H12, use a filament that is transverse (side-to-side) and/or offset (not on the axis of the bulb) central axis of the headlamp reflector). In this case, it is impossible even to roughly approximate the position and orientation of the filament with a "retrofit" HID capsule. Just because your headlamp might use an axial-filament bulb, though, doesn't mean you've jumped the hurdles—the laws of optical physics don't bend even for the cleverest marketing department, nor for the catchiest HID "retrofit" kit box.


The latest gimmick is HID arc capsules set in an electromagnetic base so that they shift up and down or back and forth. These are being marketed as "dual beam" kits that claim to address the loss of high beam with fixed-base "retrofits" in place of dual-filament halogen bulbs. (A cheaper variant of this is one that uses a fixed HID bulb with a halogen bulb strapped or glued to the side of it...yikes!) What you wind up with is two poorly-formed beams, at best. The reason the original equipment market has not adopted the movable-capsule designs they've been playing with since the mid 1990s is because it is impossible to control the arc position accurately so it winds up in the same position each and every time.

In the original-equipment field, there are single-capsule dual-beam systems appearing ("BiXenon", etc.), but these all rely on a movable optical shield, or movable reflector—the arc capsule stays in one place. The Original Equipment engineers have a great deal of money and resources at their disposal, and if a movable capsule were a practical way to do the job, they'd do it. The "retrofit" kits certainly don't address this problem anywhere near satisfaction. And even if they did, remember: Whether a fixed or moving-capsule "retrofit" is contemplated, solving the arc-position problem and calling it good is like going to a hospital with two broken ribs, a sprained ankle and a crushed toe and having the nurse say "Well, you're free to go home now, we've put your ankle in a sling!" Focal length (arc/filament positioning) is only just ONE issue out of several.

The most dangerous part of the attempt to "retrofit" Xenon headlamps is that sometimes you get a deceptive and illusory "improvement" in the performance of the headlamp. The performance of the headlamp is perceived to be "better" because of the much higher level of foreground lighting (on the road immediately in front of the car). However, the beam patterns produced by this kind of "conversion" virtually always give less distance light, and often an alarming lack of light where there's meant to be a relative maximum in light intensity. The result is the illusion that you can see better than you actually can, and that's not safe.

It's tricky to judge headlamp beam performance without a lot of knowledge, a lot of training and a lot of special equipment, because subjective perceptions are very misleading. Having a lot of strong light in the foreground, that is on the road close to the car and out to the sides, is very comforting and reliably produces a strong impression of "good headlights". The problem is that not only is foreground lighting of decidedly secondary importance when travelling much above 30 mph, but having a very strong pool of light close to the car causes your pupils to close down, worsening your distance vision...all the while giving you this false sense of security. This is to say nothing of the massive amounts of glare to other road users and backdazzle to you, the driver, that results from these "retrofits".

HID headlamps also require careful weatherproofing and electrical shielding because of the high voltages involved. These unsafe "retrofits" make it physically possible to insert an HID bulb where a halogen bulb belongs, but this practice is illegal and dangerous, regardless of claims by these marketers that their systems are "beam pattern corrected" or the fraudulent use of established brand names to try to trick you into thinking the product is legitimate. In order to work correctly and safely, HID headlamps must be designed from the start as HID headlamps.

What about the law, what does it have to say on the matter? In virtually every first-world country, HID "retrofits" into halogen headlamps are illegal. They're illegal clear across Europe and in all of the many countries that use European ECE headlight regulations. They're illegal in the US and Canada. Some people dismiss this because North American regulations, in particular, are written in such a manner as to reject a great many genuinely good headlamps. Nevertheless, on the particular count of HID "retrofits" into halogen headlamps, the world's regulators and engineers agree: DON'T!

The only safe and legitimate HID retrofit is one that replaces the entire headlamp—that is lens, reflector, bulb...the WHOLE shemozzle—with optics designed for HID usage. In the aftermarket, it is possible to get clever with the growing number of available products, such as Hella's modular projectors available in HID or halogen, and fabricate your own brackets and bezels, or to modify an original-equipment halogen headlamp housing to contain optical "guts" designed for HID usage. But just putting an HID bulb where a halogen one belongs is bad news all around.



[SIZE=+1]Please note:[/SIZE] From time to time, I am asked to comment on what are marketed as "new developments" in HID kits, and those asking sometimes point out to me that these "new developments" might render this article out-of-date, since the copyright date on the article is older than the date of these "new developments". Please understand, marketeers will always be coming up with dazzling new pseudoscience, tempting new hype and sneaky new ways of trying to convince you to buy their stuff. It's what they do. This article will never go out of date, because the problems with HID kits are conceptual problems, not problems of implementation. Therefore, they cannot be overcome by additional research and development, any more than someone could develop a way for you to put on somebody else's eyeglasses and see correctly.

 

[Octavian]

I posed my question to Daniel. Here's how he replied:

This is a typical HID cluster salesman's pitch. To make things worse, it is right with quite a few inferior aftermarket kits. But it is not right for all kit/headlight combinations.

Yes HID lights are sooo different, of course.... except if you look into ETOS/ETKA or compare on real car, optically the headlight clusters for Superb differ in ... wait for it... nothing between HID and non-HID version.

Sure, there is a ballast for HID, and the bulb holder is different to accept the D1S and place the arc at the correct position, plus finally the levelling motors use different signalling to allow front/rear automatic headlight levelling. But optically, headlights are the same. And so they should be, as a well designed projector headlight really should not care what is used to generate light at the focal point.

Years ago I did a PhD in high power lasers , so I might just know what I am talking about

I really liked the section which first said that projectors really do not care about the light source, but then pointed out that cutoff is not everything. It is not, but it is THE problem of retrofits, especially the reflector type arrangements. Usually, if you look at problems other than the cutoff, the main issue is the slight shadow caused by the HID bulb support. Does not bother. In general, the projector light arrangement replicates the light/shadow pattern inside the reflector at infinite distance from the headlight (ie in the far field, but generally even a few tens of headlight focal depth are enough). Unless you have a seriously strange light source behind the cutoff edge inside the headlight, you'll be OK. Typical problem case are H3 retrofits, as these quite often stick too far into the reflector and the light source is too close or even past the focal pattern.

Most of the problems that happen, happen with the reflector type arrangements, I'd say never ever retrofit HIDs to reflector type clusters
Unfortunately, many do.

I also want to point out that a lot of problems people are having with retrofits are electrical.

HID headlamps also require careful weatherproofing and electrical shielding because of the high voltages involved. These unsafe "retrofits" make it physically possible to insert an HID bulb where a halogen bulb belongs, but this practice is illegal and dangerous, regardless of claims by these marketers that their systems are "beam pattern corrected" or the fraudulent use of established brand names to try to trick you into thinking the product is legitimate. In order to work correctly and safely, HID headlamps must be designed from the start as HID headlamps.

Yes, get scared, run away and pay 5 times more for headlight clusters, which may be identical to the one you are using now, except for a Philips ballast and a different bulb holder. You will still have to spend a lot of effort on upgrading the wiring, and on complete replacement of your perfectly good levelling system with another, less than ideal one.

As for legality, of course anything that costs 3x cheaper aftermarket than from factory, must be illegal, otherwise the motoring industry clique would not be able to rip you off at each new car purchase High beam DRLs are legal in US, but illegal in Europe. Does that mean that they do not work in Europe I did not think so.

Having said all that, I do not advocate retrofits over factory fit. I had both. It is just that for my specific needs, the automatic headlamp adjustment never worked when the car had full boot of stuff, the headlights would then point 20 deg into the ground. The combination of manual in-cabin levelling as for halogens, plus HID inserts works better for me. Please also note that on my car there is little difference betwen the 2 types, and that the wiring is good for 15A+ per light, not a typical 8A+ per light. This changes the perspective.

I got the kit from XenonDepot. Good one, uses Philips components for the lot. But I would love to know a kit manufacturer that uses D1S bulbs, so that there is one box less to fit around the car.

Finally, I guess that Daniel sells entire headlight clusters

 

[arvina]

sweet!!! PHD in high powered lasers?!
what kind of cool star wars stuff have you seen?!

holy freakin sweet!

 

[Octavian]

sweet!!! PHD in high powered lasers?!
what kind of cool star wars stuff have you seen?!

holy freakin sweet!

No star wars here, CO2 lasers, more like blasting concrete and marking the packaging with non-removable characters. I did some new diffractive optics designs and a lot of propagation simulation work. there was also a fair amount of practical work involved, incl high power RF feed and plasma properties. There are probably people here who do optics design for a living and know 5x times more on optics than I do, but nevertheless I can see more than just general picture.

I moved away from that since, and went to mobile comms L1 software/hardware instead. Wireless has been my interest for many years prior to that stint in laser simulation, plus for a family guy like myself the paycheck is important.

Now, if only I could find someone who'd let me do engine management algorithms work and still pay for it...

 

[Pelican18TQA4]

I've got OEM Bi-Xenons in my car (a bargain at $600 factory option ) and I have a friend who has an aftermarket HID retro kit in her New Beetle. Putting the cars side-by-side facing a wall, the cutoff is very similar on both cars. The only difference really is the "hotspot" in the center of the cutoff that is so typical of DOT projector headlights. I've been driving down the road at night, facing her oncoming car and I've never noted any glare or anything strange. Also, the spread of the light in front of the car is very even and lights throws down the road no worse than it did with the Halogen bulbs. I agree, HID retrofit in a feflector headlight is bad news. In a projector headlight, I think it depends on the quality of the optics to begin with.

 

[dieseldorf]

Silverstars in! Lighting much improved

 

[dieselgti]

Great! Osram Silverstars? Or Sylvania Silverstars? I'm thinking about picking up a set of H4 Osrams. It's good to hear there is a improvement!

Silverstars in! Lighting much improved

 

[LNXGUY]

If you are worried about the HID's for hi-beams, why not get sme higher wattage bulbs for the hi's and run some relays? Alot cheaper, and the light output would probably be alot better.

No matter how you cut it, more wattage = more light.

 

[dieselgti]

No matter how you cut it, more wattage = more light.

My biggest concern is that more wattage = more light = higher temps. Even with relays I'd be concered about the wiring in the light and the housing itself. I'd hate to see the mess you'd be in if you started melting the OEM housing... I dont' think you can replace only the hi beam housing in those lights.

 

[dieseldorf]

let there be light

Osram Silverstars?

OSRAM, of course

 

[compu_85]

Do you still have the original lights? Could you 'swap' in the high beam housings over if you had an oops?

Are they glass or plastic?

-J

 

[Octavian]

My biggest concern is that more wattage = more light = higher temps. Even with relays I'd be concered about the wiring in the light and the housing itself. I'd hate to see the mess you'd be in if you started melting the OEM housing... I dont' think you can replace only the hi beam housing in those lights.

One thing that I noticed in my superb's headlights: The wiring to each headlight is 15A+, but the wires inside the headlight are at least 2.5-3 times thinner. I am not exageratting, the surface area must be 6-9 times smaller, so that little 20cm piece of wire folded inside the headlight adds as much voltage drop as the rest of the wiring harness Probably a result of cost saving exercise, these wires are in hi-temp insulation, so I guess someone assumed it does not matter that they heat up from the current as well as from the headlight...

With this in mind, I routed the power to HID inserts over separate wires

 

[JWaltersTDI]

Has anyone tried HID's in e-codes for a MK4?