Xenon headlight bulb upgrade - whats that all about?

Many years ago I had some 100/160 and a quick check shows they are still available. All a brighter lamp on dip does if it is correctly adjusted is light up the same amount of surface but to a greater intensity so the eyes don't suffer as much from being plunged into a black hole. A mod was to wire lamps with a relay so dip was on all the time and was not extinguished when main was selected. I tried it expecting the lamps to have very short life due to heat but they seemed to last a reasonable time.

G.Harman

You have to be sure you don't have plastic lamp housings or they may melt.

It was also necessary to use the headlamp feed wire to operate a relay, rather than the lamp directly, or the extra current draw would melt the insulation.

Colin Bignell

As 'main beam' on a rally car included a couple of Cibie Oscar spots, set up to cross about 300 yards out, and a couple of Cibie Oscar fog lights, also set up to cross but much closer, to light the sides of the road, the contrast with dipped beam was quite significant.

Not really necessary with the rally lamp set-up above.

Colin Bignell

In message , Nightjar writes

I was quite surprised, (easily surprised me), when I was doing some work on a new car recently and just to see what the effect would be I ran a short lead to the main beam rather than using the vehicle loom. There was a noticeable increase in illumination. I never got around to measuring the drop in the loom and as it was a company car I didn't fit a relay. If it had been mine I certainly would have fitted one.

Naw you want and electronic rearview mirror. Bloomin' brilliant things.

Doesn't help with the glare from HID lamps fitted to oncoming vehicles though. Uneven roads are horrible, the sharp cut off almost making the damn things flash at you.

The higher mounting is ideal for hitting door mirrors particularly when the driver would clearly prefer to be in the space you are occupying:-(

regards

Meh, the ones I have are fine. Their "pro" sockets and tools are pretty good value for money as well. But yes as with many retailers they do stock s**te as well...

Never got into motorsports but heck of a lot of my life many journeys have been on country roads many unfenced so I have always liked decent illumination. remember being disappointed to find that Aircraft landing lights were 28 volt. Dad did have one he got as war surplus and must have been an early example of a sealed beam unit,he aquired a Dynamo as well which is still around in the shed rated 100 amp 28 volt but never got around to fitting it to an engine. I did fit the lamp to my A35 van coupled to some tractor batteries which was fun at the time. Quite bright 40+ years ago but easily beaten now,KC daylighter sealed beam units look almost identical to it.

G.Harman

And probably gave nowhere near the intended light level as the designed voltage would have been an 'on charge' one. Make a very big difference to the light output of tungsten.

HID are much more efficient, so heat isn't the same problem. Think I've read LED headlamps are becoming available.

According to the kit-car forums, there are two exemptions: self-levelling headlights are not required if the car has self-levelling suspension and neither is required if the car is a sports type with a stiff suspension. Both of which do seem reasonable.

SteveW

Sorry I don't have HID lights so I don't know: why is having a headlamp washer so important?

TIA

If you have ever driven any long distance in the winter and noted how often you used the windscreen washer, you'd ralise how useful a headlamp washer is. Why is it needed for HID lights? Don't know but guessing that if the light (and heat) doesn't get out the front it would build up in the unit and damage it.

Dirty lenses cause light scatter which could increase dazzle.

HIDs are much more efficient than halogen so produce less heat. Common HIDs are 35 watt - halogen 55.

Thanks for the explanation.

I don't doubt that a washer would be useful. I was just puzzled why they had to be on HID lights but not compulsory on anything else, but Dave has answered that question now. It is strange that more cars don't have washers or wipers on their lights but I suppose it is added cost for little perceived benefit.