[s-cars] hid 'upgrades'
Chris Covington
malth at umich.edu
Tue Jul 9 20:20:36 EDT 2002
Bob,
You're right, I wasn't specifically addressing your kit. How similar are
the new A6 and urS6 housings? It sounds like you have all the legitimate
parts, but for a different headlamp assembly which could produce erroneous
output even if it "seems" OK, as per that link - you really need a certain
expertise and equipment to be able to judge if it is correct.
Cov
'91 200q20v
On Tue, 9 Jul 2002, Robert Pastore wrote:
> Chris:
>
> Agree with what you've said regarding most HID kits, and I don't think your
> post was intended as a direct response to my conversion.
>
> Still, I wanted to clarify that the entire reflector module (including
> convex refectory lens, reflector, bulb and ballast) from the new A6 xenon
> was grafted into the Ur housing by means of an adapter bracket in the
> conversion that both Igor and I completed. Since the entire "bullet" is
> replaced as a unit, the beam pattern is new A6. What is lost versus OEM,
> and is annoying to other drivers, is the auto dimming feature, so if my car
> is loaded down or I am on an incline, I get some protests from drivers in
> the oncoming lane. I have the auto dimming stepper motors from the new A6
> housings, and can confirm that they will fit without modification into the
> Ur housing, but I haven't tried to figure out the circuit to needed to
> operate them and to keep them in synch with each other. Too many little blue
> wires and too little time for me to bother.
>
> This is a fairly inexpensive way to have outstanding lighting, and keep
> factory part numbers throughout. It addresses and corrects most of the
> shortcomings of the aftermarket kits.
>
> Bob
>
>
> -----Original Message-----
> From: Chris Covington [mailto:malth at umich.edu]
> Sent: Tuesday, July 09, 2002 6:28 PM
> To: Kenneth Chang
> Cc: s-car-list at audifans.com
> Subject: [s-cars] hid 'upgrades'
>
>
> People have 'upgraded' their UrSs to Xenon, however that is not the proper
> light source originally engineered for the headlights and it does not
> produce the correct output, even if it does 'seem' brighter to others -
> it's also probably very disturbing.
>
> The only proper, legitimate way to do this is to get the factory Euro C4
> HID headlight system and install it.
>
> Here's why:
>
> (Read from:
>
> http://lighting.mbz.org/tech/info/bulbs/HID/conversion/)
>
> "Trying to "convert" halogen headlamps to HID is an unsafe thing to do.
> There are *NO* legitimate or safe HID retrofits for the headlamps of any
> car which didn't have HID lamps as a factory option. Here's why:
> HID (High Intensity Discharge) headlamps use an arc capsule where an arc
> jumps between two electrodes. This arc is used as the light source,
> instead of a glowing filament. Not only is it very important to have the
> light source (filament or arc) at exactly the right spot in the reflector
> for the lamp to produce a proper beam, but the source (filament or arc)
> must also be oriented correctly--either fore-and-aft, or side-to-side,
> depending on the design of the lamp. In addition, headlamps that produce
> both a high and a low beam must have a bulb with not one, but TWO
> filaments, each of which must be very precisely located and, in the case
> of some low beam filaments, shielded. In this game, fractions of a
> millimeter count! The only way to assure the correct placement of the
> source in the lamp is to use the correct bulb type. Most people don't
> realize this, however, and there are some unscrupulous types, placing
> their wallets before your safety, who make a buck off of your NOT knowing
> how crucial it is to use the correct source in your headlamp.
>
> These "conversions" generally consist of a headlamp bulb base that has
> been drilled-out, with an HID arc capsule crammed in and glued. Sometimes
> instead, there's a semipermanent adaptor plate that fits where the bulb
> would go, with the HID arc capsule fitting inside of the plate.
>
> There are no HID arc capsules that have more than one arc (i.e. high beam
> and low beam in one capsule, as found in 9004, 9007, H4, HB2, and most all
> sealed-beam headlamps.
>
> There are no HID arc capsules that have a transverse (side-to-side) arc
> path. 9004 headlamps and most all sealed beams use transverse filaments.
>
> Even if we consider replacing a single-axial-filament bulb with a
> single-axial-arc capsule, these so-called conversions are unsafe. The
> quantity and nature of the light put out by the arc is quite different
> from that of the filament, and the reflector and optics of a halogen
> headlamp are not designed to produce a proper headlamp beam with anything
> but a halogen bulb. Even assuming the arc position were perfectly
> matched-up with the filament position, the nature of the light from an HID
> capsule is such that the resultant beam pattern will usually produce very
> much excessive glare to oncoming drivers and backdazzle to the driver in
> bad weather, and will fail to illuminate properly the places in the
> driver's field of vision that really need to be illuminated.
>
> The folks pushing these "conversions" assure their customers that it's not
> particularly crucial to get the source position exactly right. I'd like to
> think that's because they simply don't know any better, that they consider
> any piece of glass with light coming out a "headlamp"...rather than to
> think that they're simply placing their personal profit over your highway
> safety.
>
> Perhaps most dangerous of all, these "conversion" pushers casually dismiss
> the fact that if you install one of their "conversions" in a system where
> the original headlamps produce both a high and a low beam, you will not
> have a high beam after the "conversion"! The pushers claim that a high
> beam is "not necessary" with HID headlamps. This is certainly quite wrong
> both from a legal perspective and a safety perspective. A low beam
> headlamp, no matter how bright, is a low beam headlamp, and cannot
> substitute for high beam.
>
>
>
> ----------------------------------------------------------------------------
> ----
>
> Now for the technical nuts 'n' bolts for those who want to know exactly
> why it won't work:
>
> ----------------------------------------------------------------------------
> ----
>
> "retrofitting" an HID arc capsule in place of a filament bulb is a very
> poor idea. There are lots of folks out there advertising "retrofits" of
> this type. In a nutshell, it is sometimes possible to physically adapt an
> arc capsule to go where a filament lamp was meant to go. It is really NOT
> possible to attain an acceptable (let alone compliant) beam pattern this
> way. Some of the "retrofits" get kind of close with regard to cutoff
> gradient and relative light levels within the beam, but most all of them
> have beam problems...improperly placed hot spot, dark spots in the center
> of the beam, excessive foreground illumination, excessive stray (glare)
> light, improper cutoff placement, etc.
>
> It is, as I say, sometimes possible to place the arc in the headlamp
> exactly where the filament was located before. However, an arc is a
> fundamentally different *kind* of light source than a glowing filament.
> The reflector and/or lens optics in a headlamp meant to take a filament
> lamp are designed specifically for the characteristics of a glowing
> filament.
>
> Many optic designs rely on the edges of the filament to shape the beam
> pattern, for instance, and there is no reason for chromatic correction to
> be worried about, because in most filament-lamp headlamps, chromatic
> aberration is not a problem. (Some polyellipsoidal optics do exhibit
> substantial prism effects at the cutoff.) The boundaries of the arc in an
> automotive HID capsule are much "fuzzier" (to use a technical term!) than
> the edges of the filament in a filament bulb. There are substantial color
> differences at different points in the arc (the edges, the ends, etc.),
> while the color of a glowing filament is relatively uniform. The arc is
> usually not the same length as the filament. For all these reasons, it is
> not reasonable to expect an acceptable beam pattern just because the arc
> is placed in the same location as the filament was.
>
> Note that this does not even address the issues raised in lamp designs in
> which the filament is not coaxial with the bulb base (9007, NDF/9008) or
> in which the filament is transverse rather than axial (H3) or transverse
> AND non-coaxial (9004). All arc capsules (D1, D1S, D1R, D2, D2S, D2R,
> 9500) have axial arc paths that are coaxial with the base. This does not
> stop "headlamp mercenaries" selling "conversions" for such headlamps. The
> resultant mess cannot be called a beam pattern, but as long as the
> "converted" lamps spray-out lots of purplish light, the purchasers of such
> "conversions" tend to be happy, not knowing and/or not caring that they
> are driving with dangerous, overly-glaring, inadequately-performing
> headlamps. ESPECIALLY if the seller of the "retrofit" has given
> ill-informed (or just plain fraudulent) assurances that the kit is "beam
> pattern corrected". There's flatly just no such a thing!
>
> Most people do not have the expertise (let alone the equipment) to judge
> the acceptability of a headlamp beam pattern. Most people can tell the
> difference between arc light (purplish) and halogen light (not purplish).
> It is certainly possible to physically place an arc capsule into a halogen
> headlamp. But for all real purposes, it is NOT possible to make an
> acceptable headlamp this way. For some cars, legitimate HID retrofit kits
> are available. These consist of complete new headlamp lens-reflector units
> to go with HID capsules and ballasts. This is the *ONLY* safe and proper
> way to put HID headlamps on a car not originally so equipped. "
>
>
>
> On Tue, 9 Jul 2002, Kenneth Chang wrote:
>
> > Has anyone installed any HID lights in their Ur? I'm thinking about some
> lltek motorsport HID Xenon upgrade kit. Has anyone tried this?
> > Ken
> >
> >
> > S4audinut at aol.com wrote:
> > >
> > > --
> > > [ Picked text/plain from multipart/alternative ]
> > > In a message dated 07/09/2002 3:28:06 PM Eastern Daylight Time,
> > > Jimmy at texasbankers.com writes:
> > >
> > > > That page must have got hammered. Even the link from their home page
> > > > doesn't seem to work. Oh well, it looked like the legit Audi press
> > > > release,
> > > > so there will be other links soon.
> > > >
> > > > Try this one:
> > > > http://www.germancarfans.com/news.cfm?NewsID=2020709.001&Page=2
> > > >
> > > > Jimmy P.
> > > >
> > > >
> > > >
> > >
> > > I think it is ugly, but I havent liked anything they have put out since
> the
> > > TT and early (not our) a4. Hyaundi and Kia seem to be building better
> > > looking cars than most of the big makers. OH well.
> > > Rod
> > > _______________________________________________
> > > S-CAR-List mailing list
> > > S-CAR-List at audifans.com
> > > http://www.audifans.com/mailman/listinfo/s-car-list
> >
> > --
> > Kenneth Chang
> >
> > Sun Microsystems, Inc.
> > 500 Eldorado Blvd, UBRM01
> > Broomfield, CO 80021
> > Email:kenneth.chang at sun.com
> > Phone: 303-880-0180
>
>
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