Quote:
Originally Posted by BillyD
Unless the kit includes a new reflector and/or housing designed specifically for the HID bulb, don't waste your money and irritate oncoming traffic with scattered light emitting from your illegal HID bulb retrofit.
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True, for the most part.
I will try one of the HID50 kits when I get around to it.
From their website:
What about H4 and 9007 bulbs?
H4 and 9007 bulbs are a bulb designers compromise that found their way on to vehicles in the economising days of the 1980s. The H4 and 9007 bulbs attempt to have a low beam and high beam in the same lamp.
Modern cars, performance cars and prestige cars are all equipped with separate low beam and high beams. This is because the direction and pattern of light required for each is very different. Quality modern headlight design not only gives cars a separate low beam lamp and high beam lamp within the headlight unit, but recognises that the low beam is more effective with a projector lamp and the high beam with a reflector lamp (see headlight unit pictured above). Trying to shoehorn a high beam and low beam into the same lamp was always going to be a poor compromise, even with the H4 halogen bulbs designed for it.
It has two filaments, at (a) different lengths from the base and (b) offset, so that they are at different axes. Neither filament is on the central axis of the bulb and the low beam filament features a large shield to prevent light travelling in one direction.
There are no really adequate HID conversion solutions to this compromised design.
In the first picture, the idea of two light sources is considered too difficult and the light produces a shielded low beam HID light only. This is clearly not a suitable replacement for a halogen H4 bulb.
The second type that are quite common from sellers of questionable integrity has a low beam HID burner (down the central axis of the bulb) and a standard halogen bulb for high beam offset to the side. Neither the HID low beam nor the halogen high beam light sources are in the correct place. The light will not produce appropriate beam pattern in either high or low beam, and HID is only available in the low beam. Another poor compromise.
The third type of H4 conversion on the left above is called a "telescopic" H4 HID. The telescopic H4 HID has a number of points on which it suffers. Firstly, the critical issue of light source placement. The real H4 halogen bulb has two offset light sources, on different axes and at different lengths from the base of the bulb. The telescopic H4 or 9007 burners have either the burner or the shield on a telescopic motor which slides either the burner or shield up and down along the axis of the bulb to replicate low and high beam. The HID burner is located on the central axis of the bulb and as such BOTH the low and high beam light sources are in the incorrect place. Further, the small telescopic motor in the base of the unit is prone to break down on cheaper units.
Finally above right, we have the dual burner, dual ballast H4 / 9007 conversion. Unfortunately even with this set up, the light sources are NOT quite in the correct positions. We have tested this type of H4 burner to see if it is worthy of selling but have been unable to get a satisfactory beam pattern. We feel strongly that any HID conversion that fails to duplicate the original design performance of the respective halogen bulb is not suitable to be called a replacement. The idea of conversion is to boost lighting performance within the same parameters of the original design.
There is no such things as a perfect H4 HID conversion. In all cases, the beam patterns distort and are not faithful to the original. It is not possible to perfectly duplicate the H4 halogen light source with a HID unit, despite the best (and worst) claims in the market. How close you get to the original beam pattern depends on how much you spend on the H4 unit. The cheap ones are abysmal, the more expensive ones are merely satisfactory.
STOP PRESS: We have just started doing single H4 kits (specifically for bikes) as we have found a high quality unit that is as close as we have seen to worthy of replicating a halogen H4 bulb's beam patterns. It does this by having the telescopic bulb at an angle to the axis of the bulb, thus getting much closer to the correct positions of the high and low beam light sources. It is available in 35 watt or 50 watt HID. If you are prepared to accept the limitations of any H4 conversion kit, then this is as good as we reckon it gets for H4 - its the best beam pattern replication we have found. It is considerably better than the dozens of others I have tried both in terms of reliability of the telescopic solenoid and in terms of light source placement. (note almost all other telescopic solenoid H4s on the market still run a telescopic unit operating along the axis of the bulb. This will give you poor beam replication)
A single 35 watt H4 with an Ultra-35 ballast to do high and low beam is now available for £99, plus £6 p&p ... in 6000K only.
A single 50 watt H4 with an Ultra-50 ballast to do high and low beam is now available for £129, plus £6 p&p ... in 6000K only.
Linear Mode
