You are right I should not comment on stock lights :person_facepalming: especially since they don’t exist at my house. I got confused because of various mods in this thread.
I think I figured out a small design flaw in the manufacturing that is causing reduced output.
It seems the new aluminum driver retaining ring is not able to fully tighten down on the driver (at least my driver). I thought it felt strange as it only tightened up to one point and then would go no further. I used some marker dots to confirm this. The ring seems to be squeezing the driver lightly instead of firmly.
The 2A difference I saw earlier with my battery tests and again a 1A difference after I swapped to 18 ga led wires. I can move the driver around when the retaining ring is about 1/16 of a turn from its “tightened” position.
So maybe the driver pcb is a bit thinner than it was supposed to be or maybe the threads are not cut far enough. Maybe they should have continued using a brass retaining ring. I’m not sure.
I will relay this information to Sofirn.
Add a tiny copper wire and see if it helps? They also anodized the driver side threads which im not a huge fan of. I think its better for heat transfer not to?
Lastly, my old 18650 sofirn bypassed tail switch broke and i probably havent changed that thing a dozen times. The wire was far too thin for how much solder they used.
Replaced the spring and bypass on that one and got 3,670lm at 0s with Samsung 25S. That one has LH351D 5000K 80CRI
Yeah, a simple copper washer should do the trick. That’s easier than my first thought of building up solder and filing down the high spots.
The inventory in amazon warehouse is still the old ones, but it has code to bring the price down to $32 for kit!
if you don’t mind the lower output or can replace new driver, just PM Sofirn for code.
Does anyone know is 42mm glass will fit into C8F? My host came with lens with no coatings so want to upgrade but I’m not sure if 42mm one from intl-outdoor.com will fit or should I just get 41,8mm.
The “42mm” one commonly marketed for the C8 fits fine, as does the stainless bezel if you fancy changing that too.
TBH I did order stainless bezel a while ago, just forgot about it, so the whole question was actually irrelevant :person_facepalming:
Thanks for the answer anyway 
I got new driver of 21700 C8F from Sofirn so I have 1 extra driver will order the host to built one with different LED but can’t decide which one to go XPL Hi for more throw or LH315D 5000K for 90 CRI ,what do you think ?
LH351D for the better color rendition and more flood.
It’ll be like a smaller Q8, so you will absolutely love it.
This is what is nice about this host. Either LED you pick will still have decent throw and flood but you can choose more of one or the other still.
More flood you say? Hmmm, what are the options for getting these leds? Can they be bought reflowed on a board or do you have to buy a host, use that mcpcb and reflow yourself?
You can reflow them yourself, but most of us, not including me of course, don’t have solder paste+temperature controlled hotplate. So it is out of the question unless you have it.
However, you can buy an MCPCB preflowed from Mtn Electronics, or even better, if you want a full light, buy this one, and select 219C version:
http://www.mtnelectronics.com/index.php?route=product/product&path=66&product_id=939&sort=pd.name&order=ASC
Leave a message saying you want 4000k 90CRI LH351Ds or 5000k 80CRI LH351Ds reflowed instead of the 219C, since they are about the same price He won’t mind at all.
You can then put in the driver of your choice in.
Dang, he only has the 18650 version host.
I guess I have to buy a 21700 host from Sofirn and reflow the leds myself. I’ve got a cheap hot air station so I can clamp the mcpcb and heat it slowly from the bottom. I’ve got solder paste, but I think you can apply some wire solder to the pads, add some extra flux and then hot air to do the reflow. I need to watch more youtube hot air reflow videos. 
There’s a first time for everything, right?
I need to do some reflo videos.
I think you can do it. You have done some mods Jason
Any codes available for this ?
Thanks,
Mike
Brite work….
Nope, $37 with battery and charger or $32 without.
Wait for 11/11 sale and install Aliexpress phone app for additional discounts. 11/11 is the Chinese Black Friday
Replaced the tail spring (large blue) and beefed up the bypass (20 gauge) on my C8F 21700 w/ LH351D 4000K 90CRI
3,177 at 0s w/ lightly used Vapcell 3750mAh 24A 21700
3,486 at 0s w/ topped off 30T Vapcell re-wrap
They use so much solder on their spring pad I was worried I would kill the switch trying to get it off since I do not have hot air gun. I clamped alligator clips on both switch legs and it seems to be fine.
Going to call this one done.
Have one more host but not sure what LEDs I wanna use with it just yet.
