Re: Are Halogen Blue- Lites the best?

Simple trick to prevent loss of radio settings, etc.

Wire up a 9 volt (216) battery through a cigarette lighter plug, and plug into the cigarette lighter socket just before you remove the battery connections.

You may need to have the ignition on ACC to connect the cig lighter, depending on vehicle (leave the radio switched off and close the doors).

The 9 volts should be enough to retain the settings in the radio.

Parts are available through most electronic parts outlets.

Dave

The left side requires the removal of the air

You may wish to include a diode in series (cathode to + terminal of battery, anode to center pin of plug) with the 9V battery and the cigarette lighter plug, to prevent the 9V battery from going 'poof' when you push the plug into the cigarette lighter... that way, the diode will be reverse biased as long as the car battery is still connected, but when the car battery is disconnected, the

9V battery will source current through the diode to the radio (and ECM, etc.).

||The left side took a bit more work to get off. There's about 3/4 inch ||of room between the headlight mount and the battery, so I had to take ||out the battery first. The left side requires the removal of the air ||intake scoop (easier than taking out the battery). After reinstalling ||the battery, I noticed that the trip odometers had reset, but the main ||odo was just fine. I suppose the main odo is based off of a mechanical ||mechanism, but the trip odo is purely electronic. I also lost all the ||presets on my radio. Why can't they build these things with some sort ||of battery/capacitive backup?

Attach a power plug (cig lighter plug) to a 9V battery, observing proper polarity. Plug it into the Power Outlet socket before pulling the battery. The 9V will keep all that stuff energized while you do your work. Texas Parts Guy

That trick doesn't work in my '02 USA-spec WRX. Tried it last week. I believe it would only work if the lighter still operates when the key is out of the ignition. In my case it does not.

Don't try taking the battery out with the key in any of the operational positions unless you want to take a chance of frying the computer(s) when the battery is taken out or put back in. It might not happen, but I'm not about to test the theory. It's almost as bad as disconnecting the battery when the car is running (to check if the alternator is actually producing current). If in fact the alternator was charging the battery, and you disconnect the battery, you'll have a momentary surge of voltage going to all of the other electrical components. It usually likes to go to the most expensive ones first.

You also reset your ECU.

Did you seize the opportunity to execute a Vishnu Reset?!?! :-))

Just to make sure. Halogen Blue is not the same as Xenon blue, right?

For Xenon you need some special kit

Different gas in the bulbs. Xenon gas vs Halogen gas.

Daniel Stern might be the one to ask. However - are you referring to Xenon HID, which isn't really "blue"? Some of the high performance halogen bulbs contain some Xenon which helps somehow to boost the output, but they're not HID; they contain a filiment.

Real HID requires a whole boatload of new parts, unless you like to blind oncoming cars or want your plastic reflectors to melt. The strange thing is that HID uses less power than halogen bulbs or capsules. My WRX manual says the WRX STi HIDs uses 35W, while my regular WRX uses 55W for the low beams.

I think he means Xenon HID arc lamps vs halogen filled filiment bulbs. Some of the halogen filled bulbs contain xenon gas, but they're not HID.

"Xenon Blue" and "Halogen Blue" are both marketing names. Neither phrase refers specifically to any one particular kind of bulb.

Yes, actually, "Xenon" (HID arc discharge) headlamps' output is significantly higher in blue light than is the output from headlamps that use filament bulbs -- regardless of what color the glass might be on the specific bulb in use.

There are all kinds of myths out there about how/why Xenon is beneficial to the performance of halogen bulbs. Without going into the picayune physics, the real reason is that it permits the filament to be "driven harder" (run at a higher surface temperature) without failing. Higher filament temperature = greater surface luminance = more/whiter light.

The DOT is cracking down hard on "HID retrofits" consisting of HID bulbs "rebased" to fit where a halogen bulb belongs. This crackdown is a good thing -- the optics to create a proper beam pattern with an HID burner are totally different from the optics to create a proper beam pattern with a glowing filament, and installing the wrong light source is just like putting on somebody else's eyeglasses.

This isn't such a strange thing -- it is the one and only real inherent advantage of an HID system over a filament system: greater luminous efficacy. In English: More light out, less electricity in. This does NOT necessarily translate, as many people think, to "HID headlamps are better than halogen ones". There exist excellent halogen headlamps and there exist lousy HID ones. The efficacy advantage is confined to the light source (bulb) only. It's still up to the lampset maker to design and build good optics to create a good beam pattern, and it's up to the automaker to fund him to do it.

These are both nominal power ratings, not actual ones. The steady-state power draw of an operating HID is around 48w, while the H1 bulb used in the regular WRX runs at between 58w and 72w.

DS

OK - I had to look that up. I guess there's someone who remaps the firmware in ECUs. Something about "Vishnu" in the user name? I was trying to figure that out, since Vishnu is the Hindu god of protection.

I used to disconnect the battery in my old car when I wanted it to start from scratch. As Yoda would say:

"You must unlearn what you have learned."

This might just be semantics, but: halogens are electro-negative elements or radical compounds which combine with a metal to form a halide salt. Examples include fluorine, chlorine, bromine and iodine. Xenon is an inert gas, and therefore incapable of reacting chemically with anything at all; It specifically therefore cannot be a halogen. So a "halogen filled bulb" cannot contain xenon, by definition.

Picking nits,

- Greg Reed

There's actually nothing strange about it at all: The high-voltage arc in a HID bulb simply converts more electrical energy to light and less to heat than a filament bulb. Electrical resistance is the enemy of most all things electrical and electronic, because it converts electrical energy to heat, which is usually not the purpose of the circuit. This is the reason why power transmission lines run at hundreds of thousands of volts -- higher voltage means less current for the same power transmission, which in turn means less power lost to the resistance of the conductors. The filament in a standard light bulb has a pretty high resistance, relative to the gap in an arc light -- once current flow is established through the arc. (An electrical arc is actually a "tunnel" of ionized gas that is highly conductive, once established.)

I've never actually used a HID light, so this is all just theory for me. But I'm betting that HID lamps actually run *cooler* than halogens. If they don't then the fact that they produce more light while drawing less power is indeed quite strange -- to the point of violating my understanding of the laws of electricity.

- Greg Reed

I stand corrected. However - the color of an HID is an inherent consequence of the light source, right? Don't they also produce more light across all wavelengths, but with a bias towards blue?

I was talking to my dad about HIDs. Even he realized this. He also knew that they might just melt down the factory assembly.

I didn't really mean it was really all that strange, just that people would find that interesting. Sure - flourescent indoor lights use less juice than regular incandescents or high-efficiency halogens for the same light output. High efficiency indoor halogens use a 12V DC power supply. I'm not sure what it does, but as an electrical engineer, I'd guess that it has something to do with light production being relative to current (i.e. same current for less voltage/power).

I'm just wondering what'll happen to lighting if 40V power supplies ever become common. I read some electronics industry article about this a few years back. I understand the auto industry would love it because they could use it for more powerful electric motors.

OK - wiggle room huh? In my industry, nominal ratings are usually centered, and plus/minus 10% is considered acceptable.

One of the respected WRX tuners...Shiv Patek (?) is his real name. His reset technique will get your advance into the higher performance range days quicker than if you just reset and drive.

Yes - I realize that. But some of the high performance bulbs are still primarily filled with halogen, but also contain some of the inert gas (AKA "noble gas) xenon. Daniel Stern stated some of the purported reasons elsewhere in this thread.

And if I recall my HS chemistry (never took it in college), there are actually some xenon compounds, although they're difficult to produce. This is a description from the chem division of Los Alamos National Lab:

"Before 1962, it had generally been assumed that xenon and other noble gases were unable to form compounds. Evidence has been mounting in the past few years that xenon, as well as other members of zero valance elements, do form compounds. Among the "compounds" of xenon now reported are sodium perxenate, xenon deuterate, xenon hydrate, difluoride, tetrafluoride, and hexafluoride. Xenon trioxide, which is highly explosive, has been prepared. More than 80 xenon compounds have been made with xenon chemically bonded to fluorine and oxygen. Some xenon compounds are colored. Metallic xenon has been produced, using several hundred kilobars of pressure. Xenon in a vacuum tube produces a beautiful blue glow when excited by an electrical discharge."

The last part would seem to describe what happens in a xenon HID capsule. What xenon does in a filiment bulb is probably different.

I'm an electrical engineer. I highly doubt that a tungsten filiment has a higher resistance than the gap across the gas in an HID capsule. An arc lamp isn't really the traditional DC V=IR relationship that you'd get in a filiment bulb. You need some sort of igniter or ballast to get an HID started, just like with flourescent lights. I don't fully understand the electronics behind arcing though, but I know it's not the same.

And as I said earlier in this thread, it wasn't really strange, but more that most people would assume that brighter HID must use more power than a filiment bulb. Also - more efficient indoor halogen lighting uses 12V DC to RAISE the current to produce MORE light relative to standard incandesent 120V AC lighting. Of course flourescent is more efficient, but some people find the color less than pleasing.

I understand they might concentrate heat in certain ways that require different reflector or base materials. Certainly how a light radiates heat/light/etc is important, and not just its total output. The Osram Silverstar bulbs I bought from Daniel Stern are rated for maybe

20% more light output than OEM, but they seem to radiate more than 20% brighter light at a far distance.

"Halogen" bulbs are not "halogen FILLED", by which it is obvious you mean "exclusively filled with halogens". So yes, you're being overly pedantic on the matter. The original name for what we know as "halogen bulbs" was "quartz-Iodine bulbs" because they were made out of fused quartz and the halogen used in the fill gas mix was primarily Iodine. Iodine is still widely used as the halogen in halogen bulbs, but the fill gas also contains such constituents as Xenon, Krypton, Argon and others (sometimes even as unexpected as Rhenium!)

DS

Depends on your definition of "inherent". There exist automotive HID burners ("bulbs") that emit next to no blue light at all. Those who've read about light color on my website might have an idea of what these look like when they're operating. Also, an operating automotive HID headlamp can look very much more or less blue depending on a bunch of factors: Inbuilt and external bulb shielding (running the burner hotter makes it less blue), degree of optical focus and placement and shape of cutoff shields in projector lamps. It's very possible to jigger the optics of a projector lamp to produce a very strong purple-blue "flash" (fringe) right at the cutoff. Several manufacturers do so with their HID *and* halogen headlamp optics because they think their customers want the headlamps to look blue. For reference:

No. The output spectrum of an automotive HID is spiky, just like any other arc-discharge or fluorescent light source. I've got a good diagram comparing the Spectral Power Distribution of a filament bulb with that of an automotive HID burner, but my scanner's not cooperating at the moment; ask again later.

HIDs: New ballasts with 42v primaries instead of 12v primaries.

Filaments: Remain 12v (some engineers want a return to 6v filament lamps for reasons of mechanical robustness and luminance; beancounters will probably nix it on wire gauge requirement basis)

LEDs: Fed per their requirements

The tolerance varies by bulb type (H1 has a different tolerance than 9004 has a different tolerance than H7 has a different tolerance than HB4, etc.) and regulation (US vs. rest-of-world).

DS