need to make sure that the ballast does not pull more current (amperage) than the fog light wires are rated to handle. Otherwise you end up with toaster wires.
I imagine the fog light wires can handle 20-30amps, but check the fuse and see what it is rated at. Then check the rated amperage of the aftermarket xenon kit.

Gcalo- I was referring to the halogen high beams, wondering what the brightest halogen bulb on market is.

Anyone know the correct kelvin measurement for Porsche HIDs?

 

Should be around 4300k.. that is the standard temperature for most OEM bulbs

 

Halogens are around 3200k, HID's are typically around 5500k-6500k.
5000k or below starts to look too yellow-white, over 6500k starts to look too blue.
Upwards of 12000k is in the purple range.

Can't seem to find a specific number for Porsche-

 

Aftermarket is typically 5500-6500K, but OEM bulbs are typically around the 4000k mark.

I just looked this up and apparently the only DOT approved HID color temp is 4100k (although you will see variation as color temperature is not a precise science and there are imperceivable differences between 4100 and 4300k bulbs).

 

Why back to halogen? I thought we were talking xenon? I don't know which is brightest.

Look at this about the Toshiba HIR's. This might help: http://www.automotiveforums.com/vbulletin/t573236.html

Again if you stay between 5,000-5,500 Kelvin you should be ok.

Forget the NHTSA levels. They are slightly too low and tend towards the yellow color of standard bulbs and halogens.

 

HID kits typically pull a bunch of power on light up, but with the bulb on they maintain less current drawn then a standard bulb.

We carry some 35w and 55w kits at work. I've got a set in my own car with zero problems.

 

Although its my first Porsche, I have owned several Audis. The Xenon kits area always "iffy" in terms of quality, and personally I would not fuss with it.

I have had computer problems, bulbs going out faster than usual, and other intermittent problems.

 

i know this thread is about foglights, but beware of changing your headlight bulbs a differ color. In some states its ilegal to have any blue or purple (6000k-12000k) coloring in the lights.

 

Screw that and get a FLIR system with a Head Mounted Display. Ok only good if your building a get away car but still.

 

i have a pair of apexcone digital ballasts (brand new) if anyone wants to give this setup a try.