Hi all, here's my tuppence' worth:
I had also ordered an aftermarket HID kit for my 156 after doing some research (not enough, apparently). Cost was around 300 Euros including shipping, a search on the web will list dozens of suppliers.
- Packaging was good, quality (from what I could tell) as well.
- The light emission point of the bulbs in the housing is exactly the same as with the standard H7 bulbs (I upgraded the driving lights i.e. low-beams). This means that the reflector should provide the same beam pattern as with the standard halogen bulbs.
- The length of the HID bulbs however was about 12mm greater
than that of the H7 bulbs. For the 156 this is a problem. The standaerd 156 housing includes a metallic "cap" supported by two struts in front of the bulb, so that no light is emitted directly from the bulb to the front of the vehicle; all visible light is provided via the reflector inside the housing.
I drilled the caps so the HID bulb would fit in comfortably with the intention of "elongating" the caps at the first opportunity.
Surprisingly even like this the beam pattern is quite good; I have checked that oncoming drivers would not be blinded until I finish working on the caps.
- Conversion kits do not include the self-levelling and sprinkler mechanisms required on all factory-fitted units in the EU. This means that the beam level needs to be manually adjusted every time there is a shift in the vehicle weight (passengers, baggage) and that the headlight lenses must always be kept clean (grime increases glare which in turn blinds oncoming traffic).
- The 6000K bulbs I had requested were out of stock so I accepted the 8000K units I was offerred. I later discovered that anything above 6000K will actually provide less
light output (lumens); the larger the temperature, the less the output. The associated colour changes from white to blueish and goes on to violet; these are only on the market to provide effect.
I strongly recommend avoiding any site that advertises HID lights above 6000K.
- I installed the ignition/ballast units on the chassis supports for the front bumper (fender), 1 on each side, using both tier-ups and double-sided adhesive. Bolting them on was an option but I did not want to drill holes in my car body. The location is pretty well protected from water & grime.
I should mention that this involves removing the bumper which in turn requires removal of both wheel fenders... (The same is required to remove the headlight housings but it is not really necessary to do this).
Some useful links if anyone is considering a similar conversion:
And the other side of the coin (although now a little out-of-date):
The perfect conversion involves using factory Xenon lamp housings (GTA xenon housings in the case of the 156) but:
- More is involved than just bolting them on. They include an auto-levelling mechanism which (please correct me if I'm wrong) receives input amongst others from a sensor that needs to be installed in the rear of the car.
- They cost around 1800 euros per pair...
Finally, a word of warning: HID/xenon bulbs are not to be confused with halogen bulbs using xenon gas; they are both commonly promoted as xenon lights but the HIDs cost about 10x more and make all the difference when it comes to visibility. Cost aside, they are easily distinguished as the HIDs always require an ignition/ballast unit. This unit+bulbs is what most kits consist of.
PS: Sorry about the length of the post, I haven't written in a while and thought I'd catch up in one go