Bumped and subscribed as related to
FM's recent sale here.
Discussing Ictorana's musings about overdrive voltage end point in that thread...
Of course, like all good Incan Jockeys, the first question is how far can I overdrive my incan bulb? Ultimately, there is only one way to know for sure. I regret only having a 30V/20A power supply, but I doubt you would want to push these bulbs much higher anyway.
We know in general that a bulb's overdrive career is improved with higher default spec rating. We know that the life rating is derived from the manufacturer (ideally) testing many hundreds/thousands of their bulbs at default voltage and determining when they die. Then they take the 50% mean peak of all the failure times, which becomes the life rating. They don't turn it off and on. They don't vibrate it. They use a clean DC supply which performs better than AC.
When looking at these Par 36 4.5" bulbs, I was drawn to Martek's brand because of price.
Looking at their website here, shows they have been in business for 35 years. I called them and asked to speak with an engineer or someone who knew advanced details about their Par36 sealed bulbs, and ended up being transferred to Bob Anzalone who I found out later is the President and has an engineering background.
I described our intended application, and used the 4587 sealed Par36 4.5" 250W 25hrs life as a discussion point. After the call, I saw that they resell a number of name brand bulbs in many sizes, so now I am guessing that the Martek brand is made by someone else, but I didn't ask that question.
In general, Bob felt there was some leeway, but the 25 hour default was limiting. He agreed a soft start, and minimizing vibration/trauma would be important. He would not commit to how much upwards leeway, even when presented with my being willing to accept only 5-8 hours of bulb life. In part, I honestly don't think most of these people in Bob's position routinely do what I did in my destructive testing to see what the failure point is with increased voltage. I also suspect that the GE is a better quality bulb than the Martek, just based upon the price.
So, ultimately we are back to where we were before I started doing destructive testing...using the bulb life as a guide...but I will likely get out the power supply and pick a couple sacrificial lambs, and slaughter them in the back yard during the day in case they explode.
Edit, now that I found GE's spec sheet pdf here, I don't see much point in going beyond the Q4509 which has 140,000 CP, life 100 hours, and only 13V. Now the only question is trying to figure out if the
GE model is twice as good as the
Martek brand. I doubt that. I'm not sure who is making what between Martek/Galaxy without talking to Martek. My live chat at Aircraft Spruce guy didn't know who made Martek. Also, note the higher price of
Galaxy 4509Q $19.95 vs. the
Martek at $14.75 In any case, I ordered two $$$ GE & two Martek 4509Q, and will destructive test the Martek, and assume the twice as expensive GE is better.
:nana: 
