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-   -   Headlight bulb advice (https://dorkiphus.net/porsche/showthread.php?t=14365)

smdubovsky 07-18-2007 08:44 AM

Two votes *AGAINST* the Silverstars! Both my wife and I have ben though about a DOZEN (total) of them in the last year. They won't last more than a few months in either her boxster or my jetta. I give up. Even the off-brand 85/100W bulbs I've tried have lasted longer. Yes, the silverstars appear slightly brighter but at the price they go for and the short life = a fleecing/raping. Could have bought HIDs for one of the cars by now as much money as I've thrown at the Silverstars...

Dr K 07-18-2007 09:05 AM

Daniel Stern is pretty amazing. I sent him an email for advice and he sent me back about 2.5 pages single-spaced! Bottom line - if you have the up-to-'86 lights, there are a lot of very bright solutions to replace the sealed beams. Some no-longer-manufactured that he has new-old stock sound pretty amazing (and bulbs available) but quite expensive.

Here's what he said to do (I did not ask his permission to use this, but you should feel free to contact him - he truly sounds like THE expert and has lots of solutions). I like the thought of the 356 lights, but since I spend time on the track, I'm going to go with H4s (if I can find a set or retrofit my original lights):
Starting with the up-to-'86 7" sealed-beam setup: Toss the sealed beams in the trash and put in a good set of 7" round European-code replaceable-bulb lens-reflector units. The up-to-'86 headlamp assemblies are readily available new or used; I see 'em go by on eBay all the time.

Or, you can cleverly put in the 356/early Beetle glass-cover headlamp assemblies, which likewise take a 7" round lens-reflector unit of your choosing. See attached; this actually works well and looks good. The 356 headlamps aren't hard to get.

Any of the options I mentioned can be set up to give you nuclear levels of
*well-focused* light. You just have to pick the look you want. My personal preference on these is the 356/early Beetle bucket assembly (the clear outer glass lens, IMO, really enhances the appearance of the car), fitted with a set of thoughtfully-selected 7" round headlamp assemblies (see below for options), with a relay installation package properly installed, and appropriate bulbs. Tying for first preference would be the pre-'86 headlamp assemblies carrying the same 7" lamp setup. The pre-'86 units are less work, but the 356/early Beetle units have the cool clear glass cover lens. Your pick.

I cannot supply those 356/early Beetle buckets, but they can easily be had from JC Whitney: http://tinyurl.com/3bmdzh

7" headlamps:
Put in a good set of 7" round European-code replaceable-bulb lens-reflector units.

Cibies are the standard choice, and they are very good indeed, though I have remaining stock on two different varieties of scarce and really excellent Marchals: Their flat-face H4 units, which kick the snot out of any other H4 headlamp made in any fitment (standard or model-specific), and their flat-face Amplilux units, which contain two separate reflectors and two separate quartz bulbs for low and high beam, in each 7" round housing.

Cibies: $62/ea
Marchal H4s: $139/ea
Marchal Ampliluxes: $239/ea

The Ampliluxes are flat-lens dual-reflector units that take *two* quartz bulbs, an H1 for low beam and an H3 for high beam. These ultrapremium lamps are no longer manufactured, but as I say, I do have new old stock remaining. They fit a standard 7" round bucket, have very good water sealing, the separate low and high bulbs mean you can install whatever wattage combination you desire, and the separate high and low reflectors mean the high beam aim can be adjusted independently of the low beam aim.
This is the _only_ 7" round lampset with that capability, which is very helpful in dialling in the headlighting beam distribution on vehicles used in nonstandard conditions (off road, severe weather, high speeds, high headlamp mounting heights, etc.). However, because these lamps were originally very expensive, and are now rather rare, they are quite costly:
$239/ea.

As for the difference between Marchal H4s and Cibie H4s (and the commonly-available Hella units): Take a look at http://www.torque.net/~dastern/Photo...ocomparo3.html .

The link takes you to isocandela diagrams for three different 7" round H4 headlamp units. Why not photographs? Because photographs of beam patterns can be very misleading even if the photographer has the best of intentions, because pixels and film work in a fundamentally different way than human eyes. First, let's look at more objective comparisons of different headlamps' beam performance. The way to do that is with isocandela diagrams, which are generated by a machine called a photogoniometer that measures the intensity of light produced by the headlamp through a large range of vertical and horizontal angles. are just like topographical (elevation) maps, except the squiggles and lines represent amounts of light, instead of elevation above sea level. The beam pattern is correctly aimed as it would be on a car on the road, and each differently-colored line represents the threshold of a particular intensity level. Each diagram is plotted on a chart calibrated in degrees.
Straight ahead is represented by (0,0), that is, zero degrees up-down and zero degrees left-right.

To get a mental approximation of the units and amounts under discussion
here:

Parking lamp: About 60 to 100 candela
Front turn signal: About 500 candela
Glaring high-beam daytime running lamps (e.g. Saturn): 8000 candela

The parameters to pay attention to are the maximum intensity and its location within the beam relative to the axial point (straight ahead, dead-center of the diagram chart) -- the less downward/rightward offset, the longer the seeing distance -- stray light outside the beam pattern (primarily above the horizon) and effective beam width (contained within the dark-turquoise 500 candela contour)

The lamp plotted at the top of the page is no longer produced, which is sad, for it is the best-performing lamp in this comparison. It is the Marchal H4 I offer. Note its extremely wide beam pattern, intense and well-placed hot spot, and very well controlled upward stray light.

The second and third diagrams are Cibie and commonly-available Hella 7"
round H4 lamps, respectively.

Things to notice about these two diagrams:

The Cibie produces a much wider beam pattern than the Hella. The 1000 candela line of the Cibie's beam pattern extends from 25 degrees Left to
25 degrees right, while the 1000 candela line of the Hella extends from 18 degrees Left to 20 degrees Right. At a distance of 50 feet from the car, this means the 1000 candela-and-brighter portion of the Hella's beam is
10.5 feet narrower than that of the Cibie. The 300 cd contour of the Cibie's pattern is *far* wider, extending from 43 degrees Left to 50 degrees Right, compared to 26 Left to 25 Right for the Hella. This means the overall useful width of the beam pattern at 25 feet from the car, as perceived by the driver, will be 40.7 feet for the Cibie and 22.3 feet for the Hella.

The high beams for these two lamps (isocandela diagrams not yet scanned
in) are very similar in overall performance and amount of light -- the critical difference is that the Cibie's high beam hot spot is located closer to (0,0) and closer to its low beam hot spot. The Hella's high beam and low beam hot spots are separated by a fairly large vertical amount, such that setting the lows where they belong results in most of the high beam light going up in the trees, but pulling the high beams down so they send light straight ahead puts the low beams 10 feet in front of the car.

Sorry, I do not presently have an isoplot for the Marchal Amplilux. With stock-wattage bulbs, its performance is comparable to the Marchal H4, with perhaps a bit greater distance reach and the ability to aim the high beam independently of the low. This independent adjustability means that with 100w bulbs in the low and high beam reflectors, you can set the lamps up to give optimal distance reach on low *and* high beam regardless of lamp mounting height. This is more difficult to achieve with a single-bulb lamp (any single-bulb lamp), though either the Cibie or the Marchal H4 single-bulb lamps are well focused such that the low and high beams work well relative to one another at most lamp mounting heights.

Bulbs: Depend on which lamps you pick.

Relay kit: $49 to $59 depending on which lamps you pick.

Can also make your brake and front / rear turn signal lamps 40% brighter for $7.10/bulb, your reversing/backup lamps 100% brighter for $8.20/bulb, and your front and rear sidemarker lights 60% brighter for $4.24/bulb.
These are all direct-swap bulbs with no wiring changes required.


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