I posted my readings in post #55 above. Interesting to see what you get. Include batteries/amps because it makes a potentially big difference on this direct drive light. I got 4.65A, which is too hot for an aluminum star to sustain well.
Ok Tom got her tested. I tested it and my Xin TD V4 back to back. I did not think to test t/c readings though. Both lights were tested on fully charged Samsung 20R’s just for grins. The Xin TD started out at 930 lumens and ended up 911 after 30 seconds. The Tangsfire started out at 1100 lumens and ended up 960 after 30 seconds. Lux testing had similar results. The Xin was rock solid at 38.7kcd. The Tangsfire started over 40kcd but dropped really fast. The best number we could duplicate was 37.5. I really do believe had I tested for a full minute it would have been quite a bit below the Xtd.
Trying to piece together a parts order with one of these on the way, will a 20mm noctigon fit in the stock pill without modification?
This is all symptoms of high amps and heat sag. You probably hit over 5A on a fresh 20R. If you used a Panasonic protected cell, amps would be within reason, but output probably below the XinTD. So the stock XinTD is 3.04A with a 20R cell, while the TansgsFire is 5A+ and not much higher at 30 secs.
Measuring with KeepPower 3400's, and using my stock XinTD C8 V4 for comparison. I ordered this XinTD C8 back on June 28th and the order says T6, but suspect it may be a U2. Here's what I got:
XinTD V4 w/XM-L2 T6 1A, 2.8A driver, KP3400 @4.19v, 2.92A tail -
lumens: 986 @start, 949 @30 secs, throw: 41.5 kcd
TangsFire C8 XM-L2 U3, KP3400 @4.20v, 3.86A tail -
lumens: 1,020 @start, 969 @30 secs, throw: 39 kcd
Never knew that both XinTD and Tangsfire C8 can throw 400 meters in stock form. 
I have ordered one Tangsfire C8 yesterday with the coupon code and hopefully it has the real DD East-092 driver as you all do.
I get about 50 kcd, or just over, after a fully mod'ed C8 with a domed XM-L2 U2 - that's at 3.85A regulated. Actually, think comfy or ouchy mentioned this (and I verified it recently), but the C8 reflectors that come with the XR-E C8's seem to be the best for throw, so you can get higher than 50 kcd. Not sure if you can buy those reflectors by themselves anywhere, but I saw good throw results on this light after modding to XM-L2 U2: FT UF C8 XR-E SS bezel.
Took mine apart to measure - it's 19.78 mm space for the star, where a Noctigon is 20.6mm. An HD 2010 has 19.4mm and I sand down 20 mm stars to fit (both SinkPAD's and Noctigons) an HD2010, so less work, but still requires some filing/sanding to make it a go. I prefer fitting 20's because it's auto-centered and if you get it to fit nice and tight, has to help with heat sinking I would think.
Just realized the TangsFire is not a standard size C8 reflector also - it's 36.6mm in depth, 32mm for the Convoy. As a result, the body's head portion is longer than a Convoy C8's. The reflector diameter OD's are close: 41.5mm for the Convoy, 40.79mm for the TangsFire.
Measurements for just the head and tube (no tail, no pill, no reflector, no lens, no bezel):
Weights: 98.2g for the TangsFire, 87.5g for the Convoy
Lengths: 123mm for the TangsFire, 115mm for the Convoy
The newer C8s, whether Tangsfire, or Ultrafire are longer with bigger reflectors. I’ve heard them referred to as C8X and other letters after the C8. That usually explains the difference in price. The $20+ ones are the newer deeper reflector ones! and the $10+ are the older smaller versions.
Interesting... Well, this depth doesn't help throw, but just reduces the spill, which may give the appearance of being brighter - same light in a more concentrated area, similar to the SupFire X5.
I recently bought an UltraFire WF-502B CREE XM-L T6 from the Greed Pays thread Greed Pays ... .
Could someone give me an idea how the beam profile of this C8 would compare to that of the 502B? Would the hot spot be wider or narrower and by how much? Which one would have more flood/spill?
This is the particular one I got:
http://www.ebay.com/itm/221335988921?ssPageName=STRK:MEWNX:IT&\_trksid=p3984.m1439.l2649
Thank you.
I had an Ultrafire 502b and it has a nice floody beam. This c8 is also floody but has a good bit of throw to go with it. I hope this helped.
I can tell you for certain in about a week or so. I have one on the way and have the same 502b.
I imagine the hotspot will be tighter/smaller and thus throw quite a bit further. Probably a bit wider spill with similar brightness. Overall output will be substantially more with the C8, the actual amount will vary quite a bit depending on battery used.
If I get it, I will use a green 3400mah protected panasonic. Someone mentioned earlier in this thread that this C8 pulls 3.5amps from these cells.
If it’s much tighter/smaller, I will probably have no use for it. For what do people use the lights which have tiny hotspots and throw very far?
Would anyone be able to say how the C8 would compare to this in terms of the tightness of the hotspot? http://dx.com/p/smallsun-zy-c37-cree-q3-wc-3-mode-170-lumen-led-flashlight-3-aaa-1-18650-19186
(this is another light I own and it has a very small hotspot)
Instead of all these comparisons, a single number, the angle of the hotspot would suffice of course.
The Tangsfire C8 will have a bigger, more usable hotspot than the Small Sun ZY-C37 and a whole lot more spill to go with it. I did a small beamshot comparison on new years day against a Xin TD which has a very similar beam profile to the Tangsfire and a Dongrui ALL 920 which has a similar profile to the ZY c37 and there is just no comparison. My laptop is messing up really bad but I will fire up my old desjtop and see if I can post the pics
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Ok here are the shots. First is the Dobgrui which has an XR-E Q5 which is just a higher bin version of the die in the Small Sun.
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Next is the Xin TD which is an XM-L2 like the Tangsfire C8.
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As you can see, the XM-L2 powered C8’s have a lot of usable spill but will still reach a ways down the road. These are from 30 meters. I need to upload the 120M ones from New Years on photobucket so I can post them. There is even more difference at that distance. If you like I can get some shots of the Tangsfire tonight and post them so you can see a direct comparison. I would do them at 120M also.
Thanks a lot manxbuggy1.
The pictures are very helpful. Could you give an idea how far the big white object in the middle is? It looks like a boat.
Yeah sorry I forgot that so I added it to the other post. It is a small paddle boat about 7’ tall. The pictures were taken at 30 meters. The longer shots show the lack of spill from the XR-E and the abundant spill of the XM-L2 even better.
would really appreciate the pics from the Tangsfire, thanks. Got notice that my light shipped, so I will get it sometime this week. So far so good from T-Mart