Aftermarket HID headlights - 35W or 55W

[HughG]

PanzerCommander said:

the 55w kit are great if you want to use the car only off road at night but I wouldn't recommend them for road use as they will be far to bright.

Thats the sort of thing I wanted to hear, thanks

[Silver Smudger]

VeeDub Geezer said:

Depending on the car, you may also benefit from fitting relays to the light loom. The difference with a relayed loom on my Corrado was night and day. Literally.

What does this mean pls?

[NomduJour]

To avoid the voltage drop, hence brighter lights.

Putting HID bulbs into a reflector designed for halogen bulbs is a conceptual non-starter. Never going to work as it should.

[PanzerCommander]

NomduJour said:

To avoid the voltage drop, hence brighter lights.

Putting HID bulbs into a reflector designed for halogen bulbs is a conceptual non-starter. Never going to work as it should.

You can get HID bulbs designed to run in reflector housings, not all HID systems are the same.

[NomduJour]

It's conceptually wrong, the light source is different and it will be a compromise.

[sparks_E39]

My E39 530 has a hid kit, a very good one at that. I've never been flashed or told by friends my lights are too bright. I do have projector lenses though and the kit isn't cheap, although it was fitted courtesy of the previous owner.

[GC8]

As touched on by others: re-earth and re-wire using a relay to switch power from a direct 12v feed. Most headlamp wiring is marginal even when new, taking the feed through the headlamp switch and if you measure the voltage available at the bulbs its frequently very low. 12v lamps make far more light at 12v than they do at 9v.

[r11co]

The 55w HID kits are a total gimmick as the number is meaningless in relation to the actual bulb output. It is just marketing hype playing on the 'bigger is better' propensity of most people.

For a standard 12v halogen bulb a 20 watt increase in consumption is significant as the bulb itself is the entire circuit (and this is what the sellers of the 55w HID kits are playing on) but in the case of HIDs the power rating refers to the consumption of the transformer/ballast unit and a 20 watt difference will have no discernible effect on the light output of the bulb as it is on the other end of the transformer circuit and relies on high voltage/low current to operate.

One of the benefits of HID is that they are much more efficient because they produce less heat, so any extra current is not going to make the bulb brighter - it'll just be wasted as heat in the transformer.

Incidentally, I concur with those who say that HID can be retrofitted to halogen lamps responsibly. It is no different to a wheel and tyre upgrade - it can be done properly and it can be done badly, which doesn't mean it should not be done at all.

NomduJour said:

It's conceptually wrong, the light source is different and it will be a compromise.

This is a wholly false generalisation. If the HID bulb is designed to produce light at the same focus point as the halogen bulb it is replacing (which provided the correct bulb is used in the correct application they all are) then this statement is untrue. The only compromises will be those already present as a result of the styling of the headlamp unit.

Edited by r11co on Saturday 1st February 17:10

[A900ss]

r11co said:

Incidentally, I concur with those who say that HID can be retrofitted to halogen lamps responsibly. It is no different to a wheel and tyre upgrade - it can be done properly and it can be done badly, which doesn't mean it should not be done at all.

So for a H4 reflector, what kit would you recommend?

[r11co]

A900ss said:

So for a H4 reflector, what kit would you recommend?

H4's are a different ball game because the HID upgrades are relying on a solenoid to reposition the focal point of the bulb for low and high beam rather than using two filaments and switching the current between them as would happen with halogen H4s.

The H4 kits I've seen (and I haven't seen a lot TBH) look a bit crappy and plasticky and I don't think I'd trust the engineering in them to last and be able to maintain focus.

However, this looks more promising!

[Rich_W]

worsy said:

Weren't these set for MOT fails under recent legislation?

It's typically vague.

http://www.motinfo.gov.uk/htdocs/m4s01000701.htm

vosa said:

may be fitted with headlamp washers and a suspension or headlamp self levelling system

which leads to RFR

rfr said:

A headlamp levelling or cleaning device inoperative or otherwise obviously defective.

So if they are there, they have to work, but they may not be fitted in which case no fail.

HOWEVER.

IME

Most Aftermarket systems fail for having no beam pattern. Just the aforementioned blob of light.

I'm told, but haven't looked into it in depth, that HID kits marker "R" are for reflector type (i.e. normal) lens and still have the flat beam and kick to the left as a result. So I guess it would be ok to pass. Or at least pass and advise "Aftermarket HID kit fitted to headlamps"

[NomduJour]

r11co said:

This is a wholly false generalisation. If the HID bulb is designed to produce light at the same focus point as the halogen bulb it is replacing (which provided the correct bulb is used in the correct application they all are) then this statement is untrue. The only compromises will be those already present as a result of the styling of the headlamp unit.

Nonsense.

There is a fundamental conceptual difference between the type of housing designed for an HID bulb and one designed for a halogen bulb because there is a fundamental conceptual difference in the source of light they use. If there wasn't, all the housings would be exactly the same and this thread wouldn't exist.

You may be able to cobble something together that looks nice and white in the McDonald's car park and doesn't blind people coming the other way, but it won't be right.

[Mr2Mike]

r11co said:

This is a wholly false generalisation. If the HID bulb is designed to produce light at the same focus point as the halogen bulb it is replacing (which provided the correct bulb is used in the correct application they all are) then this statement is untrue. The only compromises will be those already present as a result of the styling of the headlamp unit.

Edited by r11co on Saturday 1st February 17:10

You clearly have little or no understanding of optics. Neither a halogen lamp nor a HID lamp creates a point source of light, and the shape of the light source varies significantly between them (halogen obviously has a long, thin cylinder shaped filament, the HID is more of a compact crescent shape). The lens and/or reflector is designed around both the position and the shape of of the light source, so whilst you can fit a HID lamp and get the light source in the right place, the shape is not correct so neither will the beam pattern be correct.

[r11co]

Mr2Mike said:

You clearly have little or no understanding of optics. Neither a halogen lamp nor a HID lamp creates a point source of light, and the shape of the light source varies significantly between them (halogen obviously has a long, thin cylinder shaped filament, the HID is more of a compact crescent shape). The lens and/or reflector is designed around both the position and the shape of of the light source, so whilst you can fit a HID lamp and get the light source in the right place, the shape is not correct so neither will the beam pattern be correct.

A focal image does not have to be one point (otherwise how would cameras work). OK, so maybe point was the wrong word to use, but if the light source is in the same place then it is irrelevant as to how it is created. Halogen bulbs actually present a longitudinal rectangle light source whereas HID bulbs produce a 'ball' so if anything the light source on an HID lamp is smaller.

The naysayers are wrong for one simple reason though - there are hundreds of thousands of cars that have passed MOT beam pattern tests that have had HIDs retrofitted, but it has become one of those issues where the fight (against) has become irrational, and those who disagree with the concept will have reasons to criticise despite the evidence to contrary, for example..

NomduJour said:

You may be able to cobble something together that looks nice and white in the McDonald's car park and doesn't blind people coming the other way, but it won't be right.

Spot the obvious contradiction in bold, but the mention of McDonalds seals the argument for the naysayer (despite it being emotive nonsense).

Edited by r11co on Sunday 2nd February 14:12

[GC8]

Most people who are anti-retrofit HID seem convinced that EVERY headlamp that dazzles them is a cheap HID fitted into an unsuitable reflector headlamp by a charver.

Virtually every excessively bright and poorly adjusted lamp that troubles me is OEM, with poorly adjusted halogen lamps second and obvious lashed-up HIDs third and extremely uncommon.

Edited by GC8 on Sunday 2nd February 15:02

[r11co]

GC8 said:

Most people who are anti-retrofit HID seem convinced that EVERY headlamp that dazzles them is a cheap HID fitted into an unsuitable reflector headlamp by a charver.

Virtually every excessively bright and poorly adjusted lamp that troubles me is OEM, with poorly adjusted halogen lamps and obvious lashed-up HIDs third and extremely uncommon.

Indeed. In my experience the most common cause of wayward beam patterns has been poor replacement of blown halogen bulbs. Lack of access and/or a lack of 'feel' for the correct positioning of the bulb results in it sitting at an angle in the housing. I've fixed more than a few of those in my time.

Then there's the people who have never figured out what that rotary control with the numbers on it next to their light switch is for!

[Zingari]

35W 4300k R type HID kit. I've had a set in my Audi for years. Set up correctly the beam pattern does not cause glare to oncoming traffic yet the penetration distance compared to ordinary bulbs is superb. Country and unlit motorway driving they are essential.

Best of all the last set cost me less than £20 (so far two years use) and no problems with MOT

[NomduJour]

r11co said:

Spot the obvious contradiction in bold, but the mention of McDonalds seals the argument for the naysayer (despite it being emotive nonsense).

So perhaps you could explain why HID headlamps don't have reflectors which are just like halogen ones? The bulbs are conceptually incompatible, it's basic physics. It's not just about what beam pattern you think you might have.

Or maybe you know more than the lighting manufacturers do.

[PanzerCommander]

NomduJour said:

So perhaps you could explain why HID headlamps don't have reflectors which are just like halogen ones? The bulbs are conceptually incompatible, it's basic physics. It's not just about what beam pattern you think you might have.

Or maybe you know more than the lighting manufacturers do.

They did in the US until the recent batch of bog eyed cars came out. The 05+ Mustang HID option was a standard reflector.

[GC8]

I can offer a long list of cars which had HID bulbs and reflector housings.