The XPG turbohead is a re-badge of the mini-turbohead found on the G&P "X" series (X-6, X-9, X-12; 2, 3, and 4 CR123 powered respectively). They never really caught on as being super popular for various reasons but they are a nice balance of size and throwing power. The "D36" standard became much more popular as it was found in the Wolf-Eyes and Pila flashlights, and then LumensFactory came along and made after-market lamps for those... The G&P implementation of the mini-turbo had one major failure, and that was the near complete lack of easy to find replacement bulbs for them. They take a bulb and bulb base very similar to the "screw in" style found on most of the G&P/etc(spiderfire/ultrafire/superfire/xpg etc) D26 style lamps, but the bulb position has to be slightly different to focus properly in the larger turbo reflector. With no cost effective way to replace the bulbs in these, they just didn't stand a chance against other options. The only way to replace the bulb at this time seems to be to just buy a whole new head... If you could always get the whole head for $15 then that would be fine, but they are normally a fair bit more expensive than that, which makes it a little hard to justify... The "X" series from G&P are harder and harder to find lately too, the scorpion style li-ion powered turbo-head lights seem to have almost completely replaced them in most resellers inventory.
Just for the sake of example, I'll throw this link in to one of the more modern revisions of the old "X" series lights. This should be using the same bulb style that your turbohead uses, just a different external head design... (this sold under the spiderfire name, which all seems to be under the "G&P/related" umbrella.)
http://cgi.ebay.com/Spiderfire-X-02...hash=item280279084377&_trksid=p3286.m63.l1177
These mini-turbo heads from G&P draw ~1.2-1.4A depending on the various revision of the bulb... There were variations over the years but they were all essentially the same concept and same ballpark of output. This load is within reason leaning on a little high for regular protected RCR123s. Safety shouldn't be an issue unless it is routinely used in a continuous run, ordinarily, flashlights are used in short bursts so it shouldn't be too bad. The IMR cells may give you a slightly noticeable increase in output/whiteness. More importantly, the IMR cells will give you much better cycle life and safety at this drain rate, so that alone would be worth the switch. The runtime wouldn't be much different as the IMR16340s come very close to the capacity of regular RCR123s in this size.
As for building a "200+" lumen light in this size... Keep in mind that as far as bulb lumens are concerned, your XPG mini-turbo head is already probably up around 200 bulb lumens, or around 125 torch lumens, (give or take).. Exact numbers are so far from being important as you really can't see small difference anyways.... but an upgrade to a true solid 200 "torch" lumens would probably be something slightly noticeable... The issue is going to be, that most of the options that have a solid 200+ torch lumens, are either available in the D26 size class, or you have to move up to a full blown 2.5" surefire turbohead (KT2).... When you start to throw in differences in beam pattern, lumen differences don't show up as each light has certain strengths. I am not supposed to say anything but I'm going to leak this in a way that is the least likely to get me in trouble and hide it in the middle of this long paragraph so as not to draw too much attention: There is a company out there somewhere that is possibly maybe working on a D36 adapter head/bezel that would be compatible with SureFire "C" style head threads. I have no information about when or where or who and am not going to speak on this further.... except to say that there are a number of neat options that pop up with this on the table, Like running an EO-9L on a pair of IMR16340 cells. It's an option you might want to keep in mind for the future if it ever comes to bear fruit
If you don't mind a KT2 kit for your light, which is a pretty beefy turbohead, then it's a really neat setup and you can start to play with a ton of options, especially if you get a FM bi-pin to MN adapter. With that adapter you can play with a lot of bulbs, all the way up to a WA1111 or 64250 in a little 2x16340 host... Which is more like 400-500 torch lumens... but only for a few minutes on those cells, hehe... For that "200" torch lumen range, the GE787 (bi-pin) or HO-M3T (lumensfactory) are great options.
I hope that helps fill in some blanks for you... There's a lot of complexity in all of this, and I appreciate that you have already spent some time reading through the charts and guide before asking some questions. There is always more that can be said on just about any topic, and the guide, while long already, still doesn't cover everything.
Eric
