Bloody hell congrats I’m throwing rice at you.
I’m throwing lap pulls at you… 
Regarding the SMD sense resistor mod. Do I solder a R100 over each resistor (R180 & R150) or completely replacing them with R100?
Where is the best place to buy R100 resistor? I only find these at FT. Are they the of same kind?
Add the R100 to the top of either existing R180 or R150. I used an 0805 size one to match the existing ones, not 1206's as linked. Post #425 here: https://budgetlightforum.com/t/-/27963. Not sure if I got mine from DigiKey or FT - got lots of them from both sources.
These should work/fit: http://www.fasttech.com/products/1002/10003143/1234405-0805-01r-smd-precision-resistors-100-piece
Resistor calc here: http://www.hobby-hour.com/electronics/smdcalc.php (R100 is same as R10)
Will that boost the current with a single cell?
I'm thinking - yes?? Hope so, think so? Can't recall if I or anyone tried this with a Y3 driver before or not. If I had time, I'd try/test it out.
Thanks for answering my questions. It really going to save me a lot of time. I will grab one Yezl before GB ends. Together with the 26mm Maxtoch mcpcb.
what about if we short the one resistor on top of it ,will we gain anything ?
I added an R100 (digikey part #408-1556-1-ND) on top of the R150 and only saw a 0.6A rise in current (measured at both emitter and tailcap). My DMM is a pretty cheap one, but it seems to measure Qlites dead on 3.00-3.05A depending on the light. The Y3 went from 2.00ish to 2.60ish at the tail before/after on one EVVA unprotected 26650 from MTN. Also compared it with another Y3 that’s dedomed but otherwise stock that measured 2.00 or so at the tail (both on fully charged EVVA 26650s). Should I add more resistors? Or add to the R180 instead of the R150? I’m pretty well ignorant about electrical engineering — just good at following the lead of the awesome members on here and halfway decent at soldering. Hoping to get the current situation figured out before throwing an XM-L2 in one and an MT-G2 in the other both reflowed on 26mm maxtoch mcpcbs. Not aiming for insane numbers… just shooting for something between 3.5A and 4.5A at the emitter on both lights.
Any help appreciated.
The 2 resistors are in parallel, so it doesn't matter which you add a piggyback resistor to. Not sure bout adding more resistors... Sure seems like the boost should have been greater... An R100 should bump the power by about 75-80% or so, I'm thinking, and you are only seeing a 30% bump... Oh boy.
Would using two or three batteries make any difference with the R100 modification?
Post #425 here: https://budgetlightforum.com/t/-/27963 -- after adding an R100, I measured 4.6A at the tail for an MT-G2 modded Y3, so, maybe does make a difference? Weird... Sorry, wish I had time to test on a XM-L2 Y3...
Anyone used one of the 26mm maxtoch mcpcbs? Is it an easy replacement?
I have not put my light together with one. The maxtoch mcpcb is 0,5mm thinner compared to stock. Not sure if that makes a difference. The place you solder the wires does not touch the reflector, so that is good. If you want to use thick wires you might want to do some very minor trimming to the mcpcb were the wires come through.
I plan to, but haven't even taken mine apart yet. I just realized that the reflector is so loose it literally rotates when I lightly flick the flashlight (I can hear it spinning). Need to work on raising the entire shelf before fitting the MaxToch mcpcb. Other than the height issue, the diameter seems to be a direct swap. Someone correct me if I'm wrong.
Ummm - 3 things with the LED/MCPCB <-> reflector height:
- stock it's not tight, apparently (don't think my original WallBuys unit had this?)
- replacing or sanding down the LED alignment piece will cause more loss of height
- replacing the MCPCB will cause more loss of height
So, you need to take all 3 issues into account for planning a height boost 
. Don't forget possible lens replacement, maybe different thickness...
^ Thanks for pointing out the lens thickness. I got the AR lens from CNQG. I haven't compared the thickness, but it's probably thinner than stock and loosened things up in my unit.
I initially looked around for a replacement o-ring, but I wasn't able to find anything in the budget-friendly realm.
I took apart my MT-G2 modded Y3 that has the R100 added (removed the MT-G2), and measured 3.55A to 3.60A with an XM-L2 and one EVVA 26650 unprotected cell. I then put in a fresh Efest 35A 186650 and measured just over 4.0A. So, I can't explain the results you got. I would highly suspect your DMM - are you using the stock leads? I use 14 AWG custom wire leads and need them to measure high amps. Please post any updates and details on your DMM and DMM wires.
This is the DMM I’m using. Been measuring driver currents up to 4.5A reliably for the last 6 mo. It’s not modified - haven’t built any lights drawing more than 6ish amps, so figured I’d get around to beefing it up with thicker leads when my flashaholism guided me to more power.
It is possible that I could have fried the R150 when I added the R100 on top of it, I suppose. But wouldn’t the current have gone down before/after if that were the case?
Y3 #1 - Stock driver, stock driver spring, dedomed stock LED on stock mcpcb, one fresh EVVA 26650 (unprotected): 2.25-2.30A
Y3 #2 - R100 added over R150, stock driver spring, stock LED, 22ga LED leads, one fresh EVVA 26650 (unprotected): 2.60-2.65A
Both Y3’s from the cnqualitygoods GB.
And for reference…
Convoy S2+ - 3.04A Qlite flashed with NLITE (8x7135’s), stock springs, solid copper spacer soldered to brass pill, 3-up dedomed XP-L V5 2As on noctigon, 22ga LED leads, fresh NCR18650PF (protected): 3.05-3.10A
I was beginning to think it was a faulty DMM for sure… now I have no idea what to think. Could there be THAT much resistance in the driver spring or did I draw two unlucky straws with the drivers in my Y3’s?