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RC
Joined: 25 Mar 2007 Posts: 2636 Location: Australia
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Posted: Tue Jun 17, 2008 12:52 am Post subject: HID HEADLIGHTS |
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The stock headlights on our cars are a major performance limitation while driving at night. Was barely adequate 30 years ago and is poor by modern standards, dangerous even at suburban speeds.
So what can we do to update our ancient candles and bring them up to new millennium standards?
Some cars will still be running around with the original sealed beam headlights, faded reflectors and scratched glass. The manual rates these at 40W lo/50W hi. Wow! Newer sealed beams are around 50/65 and have an improved reflective coating. Just replacing these will improve your night vision for a low cost.
The next step is to replace the marginal sealed beams with a 7" reflector housing and lens that will accept H4 type bulbs. Replacements are available at most FLAPS, similar and likely cheaper than these at Pelican:
Suitable H4 base halogen bulbs to suit are available from around 50/65W up to 150/100 and possibly higher.
Rather than use the Hella brand replacements that were harder to obtain in Oz and also more expensive I chose to use a generic Japanese style 7" reflector that although has different mounting tabs was only $20. Since one of my original lights had a cracked lens and both reflectors were dim, I removed the glass and cut out the rear light section. The new reflectors fitted inside and are stuck there with silicone, allowing me to use the original housing and adjustment screws. This is how they look:
With 130/90 halogen bulbs fitted this is a dramatic improvement. The downside however is that the stock wiring and light switch is NOT DESIGNED to cope with the additional current drawn by more powerful bulbs. I strongly advise against merely increasing bulb power and upping the fuse rating.
The best option is to use relays to switch the high and low beams independently, using the existing wiring to energize the relay and switch the higher current supplied from a heavy gauge cable directly from the battery, via an appropriate inline fuse. This method not only saves your wiring, switch and change over relay (since the relay only draws about 1/10 Amp) but also minimizes voltage drop to the lights and permits them to operate at maximum efficiency.
Now to the new age in automotive illumination - HID or high intensity discharge lighting. Incandescent bulbs, including halogen, emit their light in the yellow - orange segment of the visible light spectrum and have a relative low efficiency, or lumens output per watt of input power. HID bulbs generate light by producing an arc in xenon gas and are considerably more efficient, thereby requiring much less power than incandescent for the equivalent amount of light. Additionally, by varying the composition of the gas in the bulb different colour temperature light is generated. For night driving a colour approaching sunlight is ideal for our eyes. The bulbs are very efficient at this colour temperature (5000-6000K), although slightly more so in the yellow spectrum (3000-4000K) and taper off as colour progresses through the blue and purple range (> 8000K). The ricer that uses the blue lights is reducing both his output efficiency and useful visual range. While the Honda with pink HIDs not only looks gay but is not getting a great performance benefit from the technology.
Compare, 130W halogen to 35W 6000K HID. Guess which is which:
Thanks to modern technology and millions of Chinese these lights are now available at an extremely attractive price. While you wont get much change from a $1000 bill at your local Hella shop, complete kits can be got for around $100 delivered on ebay and the like as well as direct importers and overseas merchants. The kit should include 2 bulbs, 2 electronic control ballasts (required for HID similar to mains powered commercial/industrial/dope growing), a switching control or actuator relay and all interconnecting wiring.
For legal street use we need a dual or hi/lo bulb and actuator to fit the H4 style reflectors. Unlike conventional lights that use two separate filaments for high and low beam and switches the power, HID installations use a single bulb and an electromagnetic solenoid that moves the bulb about 3mm (1/8"). Comparison between new and old bulbs:
The kit I used and others I`ve seen take their supply from an independent fused connection direct to the battery. This is extremely advantageous for our application since there is virtually no load on the existing light circuit and no extra relays or wiring is needed. There is a 3 pin plug supplied that directly fits the head light socket (if you have one) or can be directly connected to the existing wiring loom for a neater permanent installation. Simply identify and connect the high, low and earth wires, twist together, solder and cover with heat shrink.
The mounting straps that were supplied looked thin and flimsy to me so I made some little stainless brackets, not really necessary but keeping with the under hood standard. This is what the ballasts look like:
For those that are interested this is an internal view of a ballast. The main PCB is potted in a silicone compound, apparently poured in as the back is filled solid, and also applied around the circumference on the top cover. My only criticism is that the tracks, surface mount components and soldered joints on the daughter board are exposed. As this is the control IC (Philips BTW) it is a potential problem due to corrosion if the seal is compromised (as it was when I removed the cover) and there is an ingress of moisture. Suggest coating any exposed areas with a NEUTRAL CURE RTV silicone (definitely not acetic cure) and resealing the lid if you go that far.
This picture shows an overview of the installation on the RHS:
Now that this upgrade is complete and I`ve done some test driving, I must exclaim that its "BRILLIANT"
Driving lights are next so watch this space.
In the meantime - Light up!
Roger |
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Rich H
Joined: 10 Jun 2007 Posts: 2665 Location: Preston, Lancs, UK
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Posted: Tue Jun 17, 2008 1:56 am Post subject: |
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Note for those in the UK:
HIDs are legal in the UK only when fitted with headlamp washers and a self levelling mechanism.
Not saying you will get pinched just for having HIDs but it could be the icing on the cake for Mr Jobsworth at the VOSA spot check roadblock or a fussy MOT station. (I have to take biscuits for the testers guide dog...)
Otherwise a really good mod and makes one hell of a difference. Seen loads on Elises and they blow the standard 55W cadles away
Rich _________________ 1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec |
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tom!
Joined: 23 Jan 2008 Posts: 66 Location: Central NL
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Posted: Tue Jun 17, 2008 2:19 am Post subject: |
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I've come across several aftermarket HID-fitted cars with conventional diffusion-lens headlights and as a fellow road user, I'm no fan. The light is spread around and as a consequence blinds oncoming traffic.
I strongly suggest going for the more modern headlight type with a clear lens, a projector-type mechanism inside and the faceted reflector used for focusing instead of the old-type lens. Those are made for HID and when properly aimed will not blind other road users. Also, improperly-made cheapo HID kits will not focus properly on the headlight reflector, so whilst putting out more light altogether they will actually put less light on the road ahead, where it's supposed to go.
Another footnote: some cheap HID sets have a habit of burning out frequently, and replacement bulbs are anything but cheap. I see lots of older cars here in Holland with one HID headlight.
I am a big fan of properly-aimed H4s and relay/upgraded wiring installs in fresh headlight units. Just measure the amount of current that's reaching your headlights right now... way below 12 V. That translates straight back to loss of Lumen on the road.
PS your car looks amazingly clean in the engine bay! _________________ 1980 924 2.0, Saturn metallic |
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RC
Joined: 25 Mar 2007 Posts: 2636 Location: Australia
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Posted: Tue Jun 17, 2008 9:32 pm Post subject: |
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Rich H wrote:
Quote: |
Note for those in the UK:
HIDs are legal in the UK only when fitted with headlamp washers and a self levelling mechanism.
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A valid point Rich, check with your local authorities regarding the legality and requirements of a HID installation. Can understand the advantage of the self leveling mechanism, especially if you carry fat chicks in the back seats, but the washers??? Perhaps the law makers think it diffuses light rather than obstructs it?
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Not saying you will get pinched just for having HIDs but it could be the icing on the cake for Mr Jobsworth at the VOSA spot check roadblock or a fussy MOT station. |
Lucky then there`s no such thing here in the land of Oz. Sure that even the states that have a RWC dont check headlight aim let alone bulb type or power. It is important to have correct aim no matter what you have. Most examiners however know nothing about these cars. They just see the badge and expect it to have fat wheels, a loud exhaust, and bright lights
tom! wrote: | I've come across several aftermarket HID-fitted cars with conventional diffusion-lens headlights and as a fellow road user, I'm no fan. The light is spread around and as a consequence blinds oncoming traffic. |
I used to think that too, but now realize that HIDs fall in the same category as big 4X4s in the city, loud subwoofers, and nuclear missiles. It`s those that don`t have them that resent those that do!
Quote: |
I strongly suggest going for the more modern headlight type with a clear lens, a projector-type mechanism inside and the faceted reflector used for focusing instead of the old-type lens. Those are made for HID and when properly aimed will not blind other road users. Also, improperly-made cheapo HID kits will not focus properly on the headlight reflector, so whilst putting out more light altogether they will actually put less light on the road ahead, where it's supposed to go. |
I agree that HID specific projector reflector/lenses are both more efficient and capable of aiming the convergent point where the regulatory authorities deem it should, while reducing scatter. They are outside the credit limit of the majority of 924 owners, and AFAIK not available in 7". The smaller ones would be ideal for a CGT conversion though.
IMO the design engineers of the bulbs I used did a remarkable job of optimizing the focal point and optics for use as a replacement in H4 reflectors. The aim is virtually identical to that of halogen, as shown in the picture of the lights on the garage door. From my observation I can state that the 35W HIDs are considerably brighter and penetrate further ahead. With the light emitted it is possible to distinguish between different colours accurately. Furthermore I am actually amazed that I have not yet been "flashed" (common in Au to signal "you`re on high beam you AH") by other drivers. In comparison I would more often get flashed while using the 90/130W halogen. Coincidently, those bulbs (conventional) have "not for use in Europe" engraved on them, so I assume the regulations there are tighter. Fortunately there are no kangaroos hopping around on your highways at night.
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Another footnote: some cheap HID sets have a habit of burning out frequently, and replacement bulbs are anything but cheap. I see lots of older cars here in Holland with one HID headlight. |
The bulbs themselves are not a great deal more costly than comparable halogen ones. Since there is no filament that is subject to considerable heat and vibration the bulbs are reputed to last around 4 times longer, 5000 + hours. Personally I have yet to see a single HID on any vehicle except a motorcycle while cars with only one incandescent bulb functioning are witnessed regularly.
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I am a big fan of properly-aimed H4s and relay/upgraded wiring installs in fresh headlight units. Just measure the amount of current that's reaching your headlights right now... way below 12 V. |
I can only guess what you mean here as I do not know what you are on about, and anyone with an understanding of electronic or electrical theory can tell that you don`t either.
Roger |
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tom!
Joined: 23 Jan 2008 Posts: 66 Location: Central NL
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Posted: Tue Jun 17, 2008 9:45 pm Post subject: |
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Gee, thanks. :?
When you measure voltage at the headlight bulbs on an old car (my '78 Audi 80, for instance) you get less than 10 V. Upgrading to better wiring with a relay got me back to 13 V, with significantly improved headlights as a result. Too-thin wiring, bad grounds, corroded contacts are the main problems.
What's wrong with that, in your view?
Oh, and I don't envy guys with blinding HIDs in lenses not designed for the purpose- I envy guys with proper setups. I really hate to blind others. _________________ 1980 924 2.0, Saturn metallic |
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Rich H
Joined: 10 Jun 2007 Posts: 2665 Location: Preston, Lancs, UK
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Posted: Tue Jun 17, 2008 10:21 pm Post subject: |
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I think its the reference to current he is on about. 10V is definatly not good, but RC also suggested fresh wiring to the lights and a relay.
I use high power bulbs in the Elise, cheap (£5 for 100W/80W) and cheerful as long as you check the wiring. The Porker I don't find too bad at all really.
The MOT tests here are very variable to say the least.
The Porker failed for "inefficient reversing lights" and "inefficient side repeaters" the worked but were apparently not bright enough, so I used my finger and cleaned the reflectors and took the repeaters off (ot compulory for a 1980 car ) I think they wanted me to buy some new bulbs!
But my elise passed despite not having a working cat-converter or any of the back lights working except the brakes! Not even an advisory!(Obviously I fixed them ASAP! ) _________________ 1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec |
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RC
Joined: 25 Mar 2007 Posts: 2636 Location: Australia
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Posted: Tue Jun 17, 2008 10:21 pm Post subject: |
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tom! wrote: | Gee, thanks. :?
When you measure voltage at the headlight bulbs on an old car (my '78 Audi 80, for instance) you get less than 10 V. Upgrading to better wiring with a relay got me back to 13 V, with significantly improved headlights as a result. Too-thin wiring, bad grounds, corroded contacts are the main problems.
What's wrong with that, in your view? |
There`s nothing wrong with reducing voltage drop to the lights. As you could have read in my initial post I mentioned it too since I`ve BTDT.
As an electronic tech it was your sentence about measuring current then referring to voltage that revealed your lack of understanding.
Quote: |
Oh, and I don't envy guys with blinding HIDs in lenses not designed for the purpose- I envy guys with proper setups. I really hate to blind others. |
Realize English is not your first language so read my post above and try to improve your comprehension.
Roger |
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tom!
Joined: 23 Jan 2008 Posts: 66 Location: Central NL
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Posted: Tue Jun 17, 2008 11:20 pm Post subject: |
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Thanks, but I could do without your sarcasm.
Sorry for using current where I should've used voltage, which was what I meant. My take is that HID without the correct headlight units is worse for other road users than properly aimed and relayed H4s, but I guess your view depends on which side of the steering wheel you're on.
There's little chance of us meeting on the roads so I don't really care which setup you run, I just wanted other forum members considering this swap to think about other options before they switch to HID. _________________ 1980 924 2.0, Saturn metallic |
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pettybird
Joined: 30 Apr 2008 Posts: 50 Location: Cleveland Ohio
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Posted: Wed Jun 18, 2008 12:49 pm Post subject: |
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i'm with Tom on this one. perhaps you just don't have the same number of idiots running around with the lights there as I do here.
also, the light's point of origin IS different with an HID due to where the light comes from WITHIN the bulb, H4 in an H4 socket be damned. this difference in location within the housing results in a different dispersion pattern, which isn't helpful to you and isn't friendly to others. even projector beam headlights aren't the same from incandescent to HID--they're specific, as well.
also, your improperly used HID's may look cooler in clear driving conditions, but your vision is WORSE in fog/snow/sleet/rain. this is due to the whiter light. yellow light is better due to its longer wavelength being able to cut through better.
I like here in the states, so I don't have to worry about you, either, but please do your homework before tearing into someone else. |
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sirNemanjapro
Joined: 21 Aug 2009 Posts: 7 Location: Cacak, Serbia
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Posted: Sat Aug 22, 2009 1:08 am Post subject: |
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Great tutorial. I would enjoy few more photos, when selecting the spot to place relay, and more photos for other assembling stuff (bulbs placing ect.). _________________ Get away from the crowd. |
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