Quote:
Originally Posted by adc
Not sure why you'd say that.
The hotter the bulb in free air, the hotter it will also be inside a sealed headlamp. 
While EAS's test won't tell the true temperature inside the headlamp, it's stil relevant as to which light source will contribute more heat. It's not like the bulb will magically be cooler inside the headlight assembly... |
Sure but you are still missing the point. It is simply NOT the bulb temperature that really matters.
What matters with regards to failure of the wiring, electronics, structural components, plastic, etc. - anything inside the headlight assembly - is the internal temperature profile of the inside of the assembly. The bulb for sure will always be a hot spot whether tested inside an actual assembly or not. Just the isolated operating temperature of the bulb is not a big deal as the bulbs themselves are obviously designed to cope with all of the heat they generate.
The point here is that heat soak (the heat generated by the engine under the hood that somewhat slowly migrates and equalizes at many locations in the under hood environment) is probably just as important as the actual bulb source. Also the other bulbs in the headlight assembly are another key factor. Keep in mind these very rough numbers:
-Total engine output: 750000 watts (not power delivered to the wheels, TOTAL output!)
-Efficieny: 40%
-Heat production: 450000 watts (60% of total)
-Bulbs inside headlamp assembly: 4
-Total bulb power: 100 watts
-Underhood temperature (near engine): 200 deg F
Compare 100 watts to 450000 watts!! Now even thought the vast majority of that 450000 or so watts of engine power wasted on heat is dissipated by the cars cooling system there is a considerable amount of truly wasted heat that contributes to the 200 deg underhood temperatures. This is probably thousands of watts. Either way it
dwarfs the 100 or so from the bulbs. Although the headlights are in a good location to get some cooling air they are also partly enclosed in the underhood environment as well. They WILL absorb underhood energy and that will be a major heat source contributing to their is situ temperature.
If you want to talk about the benefits of a cooler bulb you must take measurements with a thermocouple, inside the headlight assembly, after full engine warm up, under steady state (or some other defined) operating conditions. If you think the insides of the headlights will show anywhere near as drastic of a temperature differences as the Angel Eye BULBS themselves, in isolation, you are sorely mistaken.
Hence again the whole bulb temperature thing is mostly a red herring.