Hi/lo beams

Discussion in 'General Motoring' started by Ken Weitzel, Sep 9, 2006.

  1. Ken Weitzel

    Joe Guest

    Got my Nighthawks @ Wal-Mart.

    Regards,
    Joe
     
    Joe, Sep 29, 2006
    #21
  2. You have no *genuine* bulb upgrade options. Sylvania will sell you
    their reduced-life, reduced-output, increased-glare, increased-price
    Silverstar bulbs (yippee...), but because the US-market PT Cruiser
    headlamp uses the straight-base variant of the 9005 high beam and 9006
    low beam bulbs, you're kind of stuck choosing between phony "upgrades"
    with blue glass (Silverstar and various others) or standard replacement
    bulbs. I agree with you, the US-market PT Cruiser's headlamps leave a
    fair amount to be desired. The low beams are amongst the "least worst"
    of the recent Chrysler offerings, but they're not great and the high
    beams might as well not exist for all the good they do.

    The rest-of-world PT Cruiser got better lamps with more efficient,
    higher-output H7 bulbs. Those lamps go by on ebay.de from time to time,
    or can be sourced new if you make contact with an overseas Chrysler
    dealer and order one 5288767AI and one 5288766AH. You'd almost
    certainly also need two 5288 904AB headlamp levelling motors in order
    to be able to adjust the aim of the export lamps, but it's possible the
    US-market manual adjusting screw assembly would pop in place where the
    motorised one is intended to go -- I'm not sure on that one.

    Easier, less costly and more effective to buy and install the Morette
    headlamp kit for the PT, *if* you can stomach the appearance (some love
    it, some hate it):

    http://www.morette.com/products/HEADLIGHTS/CHRYSLER/hl_cy_ptcruiser.htm
    (shoot me an e-mail, dastern (at) torque (dot) net if you are having
    trouble finding the Morette kit in North America.)
     
    Daniel J. Stern, Sep 29, 2006
    #22
  3. Ken Weitzel

    DeserTBoB Guest

    Hmmm...it oddly makes the PT look like a....1961 Newport! It HAS to
    be better than USA stock, though. The 300 headlamps are equally bad,
    but I only saw them on a test drive. I did feel like I was "flying
    blind" with low beams, however, with two little white hot spots
    dancing on the asphalt ahead..
     
    DeserTBoB, Sep 29, 2006
    #23
  4. Hmmm. I have a pretty direct line to product news out of Sylvania, and
    I keep a sharp eye out for new or modified product lines, but I haven't
    seen any segmented-reflector sealed beam headlamps out of Sylvania or
    any of the other makers. Your M-body would take H4656 high/low and
    H4651 high-beam units, and as far as I'm aware, the only Silverstar
    beams in those sizes are the parabolic-reflector, lens-optic type. Show
    us a picture or weblink to what you bought and let's see what it is.
    (Even if Sylvania suddenly saw the light and produced an
    optically-accurate reflector-optic range of sealed beams, if they are
    sold under the Silverstar name, they have that light-stealing,
    glare-increasing, life-cutting blue glass coating, which is a silly
    marketeering gimmick that makes the lamp a nonstarter as far as
    meaningful seeing performance improvement goes).
    And short seeing distance, owing to Chrysler's insistence on cheap
    headlamps using VOR low beam patterns instead of putting more money
    into good optics and specifying VOL low beam cutoffs. The VOR is the
    type with a cutoff at the top of the right side of the low beam (it's
    allowed to extend horizontally over to the left, too, but it has to be
    present at the top of the right side). This is basically a
    straight-across cutoff, fog lamp style, aimed at the horizon. You can
    get decent width, but in-lane beam reach is often poor because there's
    very little light above horizontal even on the side of the beam facing
    away from traffic.

    VOL, the other visually-aimed low beam pattern allowed in the US, is
    conceptually similar to the rest-of-world European ECE low beam: the
    cutoff extends leftward from the top-center of the low beam, and is
    aimed slightly below the horizon. To the right of center, the cutoff
    either dissolves, steps upward, or sweeps upward at an angle. This
    means in-lane seeing distance can be longer with thoughtful optical
    design, because the upstep/upsweep throws light well down the right
    side of your own lane. Europe has used low beams like this since 1952
    without a problem (England since '73, Australia since '71, Japan since
    '90...). But when Chrysler put VOL headlamps on the Pacifica, lazy
    dealers were refusing to educate customers who thought they were seeing
    the left light aimed lower than the right light (they were actually
    seeing the stair-step cutoff produced by BOTH lights). Rather than put
    a paragraph and diagram in the owner's manual or put out a service
    bulletin, Chrysler bitched to lampmakers that VOL low beams were
    costing them too much money in warranty headlamp re-aims and started
    specifying VORs for almost all their headlamps.
    I'm still keenly interested to see what it is you have there.
    Well, filtered towards the blue (not the green) by coating the bulb
    glass blue. This suppresses the yellow light which is most effective at
    making the human visual system work, but allows the marketeers to
    babble about "closer to natural sunlight" and "the look of expensive
    HID" and blahbitty blah blah blah.
    I believe it. Though, to be perfectly fair, sealed beam headlamps in
    general aren't very precise optical instruments under the best of
    conditions, and most of them are poorly made on old tooling nowtimes.
    For anyone who cares, here is a report I wrote up after doing some
    dissective analysis of various sealed beams a couple years ago:

    This is a report of the results of disassembly and analysis of several
    different 200mm x 142mm (2B1) rectangular sealed beams.

    GE has recently released a new line ("Nighthawk") of high performance
    bulbs and sealed beams. Their beam formation is certainly better in
    several respects than other sealed beams: Overall focus is definitely
    better, the hot spot is reasonably well shaped and placed and is
    intense,
    and the beam is considerably wider. There is no efficacy-reducing blue
    glass in the lens, reflector or burner envelope (such blue glass is
    found
    in e.g. Sylvania Silverstar and Wagner TruView).

    Foreground light is still rather lacking with the NightHawk, but the
    bigger inadequacy is that a mask is not used during aluminization, so
    the
    optically useless floor and ceiling of the lamp are covered with shiny
    stuff, same as the parabolic reflector. Therefore, light from the
    filaments hits the floor and ceiling and is emitted from the headlamp
    as
    optically uncontrolled upward stray light, which causes glare and
    backdazzle in bad weather.

    In the 1970s when the idea of rectangular sealed beam headlamps was
    being
    discussed as a possibility, there was scarcely any objection to this
    big
    increase in stray light which does not exist with round lamps that have
    no
    floors and ceilings. The only concerns voiced were to do with marketing
    and interchangeability. This is probably because halogen sealed beams
    were
    still far in the future at the time, and it is much easier to put an
    effective filament shield (rain cap, fog cap) on filaments that are not
    enclosed in a halogen capsule. The tungsten sealed beams had beam
    patterns
    with a great deal of uplight, but very little vertical stray light,
    because the filament shielding was good. Halogen sealed beams all rely
    on
    the poor shielding job done by the blacktop at the forward end of the
    burner. Not that an effective bulb shield *couldn't* be incorporated
    into
    a halogen sealed beam -- it's been done in European-spec sealed beams
    in
    the past, and Koito made some DOT H6052s with bulb shields for
    Mitsubishi in the mid-
    1980s -- but nobody does so in current-production sealed beams.

    One of the goals of this experiment was to mask the floor, ceiling and
    other optically-useless and distorted areas to observe the effect on
    glare and backdazzle.

    The lenses were removed from the reflectors of a GE standard 6052, a GE
    NightHawk H6054NH and a Sylvania XtraVision H6054XV.

    NB- GE stopped making nonhalogen sealed beam headlamps some time back;
    everything uses a halogen burner now, even the ones in "standard
    tungsten"
    boxes. These lamps now use twin-transverse-filament halogen burners
    with
    the wattage and flux adjusted to approximate the characteristics of the
    previous nonhalogen assemblies. As is the case with most halogen sealed
    beams, beam focus and stray light are worse than tungsten non-halogen
    beam
    units, and they suffer from all the problems endemic to most US sealed
    beam headlamps: Poor beam focus with excessive uplight and upward
    stray
    light.

    The unlensed beam of the 6052 is a very poorly focused diagonal(!)
    oblong
    of "blotchy" light (gradients/streaks within the oblong). There's just
    no
    way to get anything even remotely approaching a well-defined beam
    pattern
    out of this. The best one can do is use the lens optics to shift enough
    light away from the upward-leftward area to comply minimally with the
    glare maxima. Heel distortion in the reflector was evident and can't
    have
    been helping any, either. Then add in the aforementioned floor and
    ceiling
    reflections *plus* light escaping the burner and travelling directly
    through the lens, and the resultant beam pattern is a sick joke.

    Next, the Night Hawk H6054NH. I applied power and examined the unlensed
    beam. These lamps use a burner with C8/C8 twin axial filaments --
    essentially an HB5 burner of 65/55w, emitting an estimated 1400/1100
    lumens high/low beam. The unlensed beam itself was very impressive: a
    tight, centrally-focused round spot of light with moderate "fingers"
    upwards and downwards. Not so impressive was the amount of stray light
    coming primarily from the reflectorized floor, directly and via the
    reflectorized ceiling, also directly from the filaments (see bulb
    shield comments above).

    I used some high-heat-resistant matte black paint on the lamp's floor,
    ceiling, distorted reflector heel directly behind the burner, burner
    legs
    and grommets, and the small distorted areas of the reflector directly
    in
    front of the locating lugs. The resultant unlensed beam pattern
    exhibited
    considerably less stray light outside the beam pattern, while the beam
    pattern itself was scarcely changed (visually -- no photogonio range
    available).

    Next, I took a look at a Sylvania Xtravision H6054XV headlamp. This
    lamp
    uses a twin-transverse C6/C6 burner -- essentially an HB1 burner but
    with
    a 65/55w high/low filament pair emitting an estimated 1300/1000 lumens.
    The beam pattern from the assembly is very poorly formed and focused.
    The
    hot zone is large, poorly defined and of low peak intensity, there is a
    large and intense vertical spike of light, absolutely zero cutoff and
    *very* high levels of upward stray and flare light outside the beam
    pattern.

    Therefore, I was surprised when I separated the lens from the reflector
    to
    find that the unlensed beam is very tight and well focused -- a
    properly
    oriented (horizontal and square with the vertical and horizontal)
    "bowtie"
    of light as one might expect to see from a transverse filament placed
    on
    the focus of a parabolic reflector. Stray light levels remained fairly
    high owing to near-heel distortions in the reflector and ghost images
    (reflections of the transverse filaments in the burner envelope glass,
    subsequently picked up and distributed by the reflector).

    I used matte black paint on the floor and ceiling, the distorted
    reflectorized area of the heel, and the burner "legs". This reduced
    reflected upward stray light considerably, but a considerable amount
    still
    remained since the levels were initially very high and ghost images
    from
    transverse filaments cannot be really effectively be dealt with -- the
    only way to mitigate or eliminate them is to use a burner with
    spherical
    rather than tubular glass, and no such burners exist. Of course, as was
    the case with the GE NightHawk, the addition of black masking material
    to
    reflective but optically-useless areas of the reflector/housing did
    nothing to attenuate the stray light coming directly from the
    filaments. A
    halfway job of containing this light was effected by masking the inside
    of
    the lens rim, but a bulb shield is really the only way to do the whole
    job.

    Prescription factors in beam formation were verified by placing
    different
    lenses in front of different reflectors. Using the lens from the
    standard
    nothing-special GE H6052 headlamp with the *reflector-burner* from the
    Sylvania H6054XV Xtravision headlamp resulted in a much better focused
    and
    formed beam pattern than from the Xtravision lens. Both of these lenses
    were designed for use with transverse filaments. Using the GE NightHawk
    lens in front of the Xtravision burner-reflector yielded a less
    well-formed beam (this lens was designed for axial filaments).

    Using the Xtravision lens in front of the transverse-filament GE H6052
    burner-reflector resulted in a poorly-focused, poorly-formed beam.

    Conclusions:

    Rectangular reflectors (those with floors and/or ceilings) need masks
    during the aluminization stage of production to keep shiny stuff off
    optically useless surfaces where it causes upward stray and glare
    light.
    Bulb shields are feasible and should be used. And, the Sylvania
    Xtravision
    lens prescription is garbage!

    (NB- the Silverstar beams use Sylvania's standard lens, not an
    Xtravision type. Focus is just as poor, but differently so.)
    Do a websearch on H4656NH and you should turn up some sources. Or you
    could put in some decent H4s. Bosch makes good ones in your size format
    and they shouldn't be too hard to find.

    DS
     
    Daniel J. Stern, Sep 29, 2006
    #24

  5. WHOA THERE big fella, WHATEVER you do, do NOT listen to a single word
    of advice that this "desertbob" douche says- he has been proven wrong
    about 10 times in the last 24 hours- his "tech tips" will destroy your
    car !
     
    duty-honor-country, Sep 30, 2006
    #25

  6. Please troll somewhere else.
     
    Charlie Deludo, Sep 30, 2006
    #26
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