Q on H3 bulb and HID conversion: can I use a spacer under the bulb?

[olsen_karl]

I'm trying to convert a set of PIAA 510 driving lights to HID. The PIAAs come with H3 bulbs, and I bought an H3 HID conversion kit from XenonDepot.

The problem I am running into is that the H3 HID bulb is quite a bit longer than the PIAA halogen H3 bulb, and the tip of the HID bulb touches the inside of the lens in the light. If I could place a spacer under the flange of the HID bulb (between the bulb and the PIAA lens), that would get me enough space so that the HID bulb no longer contacts the inside of the lens.

Any reason I can't or shouldn't do this? A single metal washer would fit, after a little Dremel work.

H3 halogen bulbs use the base (flange) of the bulb as the ground, but the H3 HID bulb does not -- it has a plastic (nylon?) base, and 2 wires connecting the bulb to the ballast assembly.

Pics here, showing the shallow front-to-back depth of the PIAA lens, and also showing the relative lengths of the PIAA H3 halogen bulb next to the HID H3 bulb.

Note -- I know I have to drill out the back of the PIAA housing in order to route the wiring, as shown in the linked thread below:
http://www.toyota120.com/forum/showthread.php?t=26856

 

[ducktapeguy]

Oh man, be prepared for the S-storm that's about to follow for asking about HID conversions into a halogen reflector :Wow1:

I'm going to assume this is going to be for off-road use only so we don't get into the whole D.S. debate on whether you should do it. I think you'll run into some problems in that the light is no longer at the right focal point, which is going to throw your beam pattern out of whack. Depending on how far you need to space it, it may be somewhat usable, or it may be crap.

 

[olsen_karl]

^^ It's for an offroad driving light -- I want a wide flood of light, and have no misconceptions about whether this is going to be street legal or blinding to oncoming drivers.

The stock PIAA halogen 55W bulbs are kind of pathetic. Had I known how weak these lights are in stock form, I wouldn't have bought the set. Now that I have it, though, I figure I'll make them brighter.

 

[ducktapeguy]

I've experimented with putting different bulbs into reflectors designed for different housings using some aluminum adapters. I don't really have an answer to your question because it just really depends on how far you need to space it out, the design of the reflectors, and your tolerance for the beam pattern.

Physically, I don't see a problem with putting a washer in there, you can make it fit without interference. Whether it's going to give you what you want is another question. Off hand, I think one problem you might have is a large dark hole right in the middle, similar to when you focus a Mag-lite to it's widest setting. If your goal is a nice even flood of light, you might be better off just selling these lights and getting a flood pattern to begin with, because there isn't really anything you can do to change the properties of the reflector.

Are the reflectors metal and the lens made of glass? If all you want is something brighter, I think they make 100W H3 bulbs that you could try first.

 

[olsen_karl]

Physically, I don't see a problem with putting a washer in there, you can make it fit without interference.

Are the reflectors metal and the lens made of glass? If all you want is something brighter, I think they make 100W H3 bulbs that you could try first.

Thanks - and good point on whether I'll end up with a big dark hole in the middle of the beam pattern. That wouldn't be good.

I think I'll try making a spacer, plug it all in, and see what the beam pattern looks like. The lens is glass, and the backside of the reflector is metal -- I assume the front (shiny) side is all metal too, but it's sealed to the lens, so I can't tell what it's made of.

 

[olsen_karl]

For future reference (for anyone considering this) -- it's doable, but kind of a PITA. The PIAA 510 (or 520, etc. -- any of the small PIAA lamps) is just a very shallow enclosure, and there isn't a lot of space inside that housing.

A M12 metric washer fits as a spacer between the HID bulb and the 510 H3 base, with some drilling (open up the inside hole of the washer to allow more clearance for the HID bulb) and some grinding (notch the exterior of the washer where the H3 base has 2 "dimple" spots poking out).

The wire retention spring clip fits over the HID bulb, with the spacer in place, and all holds together firmly. A single washer is enough to space the tip of the HID bulb back from the lens.

Testing it in the garage, the beam pattern doesn't seem to have any big dark splotches. I haven't finished up mounting the lights back on the bumper and testing it out on the street at night -- hopefully will get that done later this week.

 

[wrcsixeight]

Is there any requirement for heat dissipation which will be affected by the adding of a spacer? If so, I'd make sure the spacer fit the housing tightly and employ some thermal grease like arctic silver 5 on mating surfaces

Not familiar with HID bulbs, except for the anger they induce when I am blinded by some tuner who put them into halogen housings.