I received several flashlights the other day from a very kind member, (but that's another story). A couple of them were UltraFire C8s. They have XR-E leds that must be in the 7000k range. They are so blue... I happen to have a couple XP-E2 leds lying around, (about 4000-4500k I believe), so I got this idea to swap out the led and keep the rest the same.
Stock XR-E on the left and modified XP-E2 on the right.
This is a very short story and there's not much to it, or much of a point, but it's a round about way to show the results.
I took the hollow pill and slid in a short piece of copper pipe and topped if off with a copper disc. Just enough material to hep get the heat to the outside of the pill.
I kept the stock driver. The whole idea was to see what the XP-E2 would do, with the same driver, but I had to change the wires and use some 22ga teflon coated, silver plated stuff. I couldn't stand that stock 30ga wire.
So it's done. I just used a tiny bit of Fujik under the star. I ended up taking a locating ring from an XB-D and opened it up to fit around the XP-E2, to center the reflector.
Ok, so what's the derned point?
Stock C8:
1.5 amps on high with a fresh 18650
24,000 lux at 1 meter.
Modded C8:
1.8 amps on high with the same 18650
34,200 Lux at 1 meter.
I was surprised to see the higher amperage, but I am thinking possibly this driver is DD on high. I didn't bother to check Medium or Low, but I will have to check now. That might, or might not, tell anything at all. If High is DD, then Medium and Low should be the same on both lights, since they would have to be regulated.
When it gets dark, I will take some comparison beam shots. There's a big difference in the beam pattern.
XR-E on the left and XP-E on the Right
Mouse Out is the XR-E and Mouse Over is the XP-E