Ok, thanks to the generosity of some BLF members I was able to order some more xhp70.2’s to test along with some more centering rings.
First here is the output test of an xhp70.2 M4 4000K 80CRI emitter.
And compared to the P2 xhp70.2:
Like a lot of high CRI Cree LED’s it does better then you would expect. The Vf is much lower which makes the lumens/Watt almost equal between the LED’s and the output is better then expected as well.
At the lower power levels it is only slightly behind and at high power levels it is only around 8% behind vs the 14% you would expect.
Now the 80CRI version does appear max out sooner, which is expected due to the thicker phosphor layer.
Overall though, it is a great LED for the GT. The lower Vf means it will run in regulation for longer then the P2 version as well and the tint is great. You can notice the higher CRI in the beam. It is worth the minor losses IMHO.
Now I would not use this LED in an FET direct drive setup, it could easily pull way too much power and go way past peak output.
Next I tried installing it in the GT.
Like before I got around 1300m of throw with the 4mm tall centering ring or around 425kcd.
I then sliced the dome and took the readings again.
With the sliced dome 80CRI xhp70.2 at 6A (forgot to take a measurement at 5A) I got around 1500m of throw or 560kcd.
Less of a gain then the P2 version got with the sliced dome for some reason but still quite good.
Like the P2 the tint did shift some, it is noticeably more yellow now, it is not for everyone that is for sure. I am debating what I will do about it myself.
I played around with the focus height as well and it really comes down to personal preference. I get the highest readings around the stock 2-2.5mm but it also has a very noticeable donut hole. Not nearly worth the ~40m of extra throw it gives.
It takes about a 3.5mm high centering ring to mostly get rid of the donut hole and 4mm gets rid of it entirely. For the very minor trade off in throw, 4mm is what I would go with. Much nicer to look at a beam without a dark spot.
It gets noticeably hotter then the xhp35 version but that is expected since it is over twice the power.
Overall impressions are that the xhp70.2 is a fantastic mod for this light if you do not need to see things a mile away. Slicing the dome is not for everyone but for those wanting more throw at the cost of a bit worse tint, it is worth it.
I sure hope that I can get Lumintop to sell an xhp70.2 mcpcb for this light after the GB is over.