MQ valve replaces most of the internals from the lower tube, valve striker, springs and sear.
You will be needing the IVG (the normal velocity adjuster on cocker's not fitted with a rex dialer), this could be an issue if you have a dialer kit fitted as you'll need to acquire a IVG.
Installation is not too difficult but will require a cocker valve tool to remove the old valve and some patience to fit the MQ without damaging it. The wires can easily be pinched/chopped if your not carefully (isn't that right VoodooDoll
).
The hardest part it timing it after installation, if the valve doesn't suit your cocker it can take some effort (and possibly ££) to get it working.
The first issue seems to be that the valve only works over quite a small pressure range from around 250 PSI to 325 PSI. (with the little white spacer shipped with later valves the working range can be altered to work up to 380 PSI)
Second issue is that eclipse boards arn't designed for the MQ. The SON parameter is used to adjust Dwell time. E1 boards only allow the SON time to be adjusted in 1ms increments which for an MQ valve is an eternity.
E2 and Zero-B boards have much better control in that they can be adjusted in 0.1ms increments, however they have the problem that the Max SON time is limited to 4ms.
For a full bodied cocker this should be fine as SON (Dwell) times of 3.5 to 4ms are about right but on a minied cocker with a much smaller air reserve 4ms may not be enough to get 280FPS even with the white spacer and pressures up to 380PSI. If this is the case and you already have a high flowing bolt the only options are to add an expansion chamber/bolt in place of the front bolt screw or fit a stock E1 board and increase the SON to 5(but you loose ramping
)
Assuming you get it installed undamaged and can get a sensible velocity then the fun really starts
The following tuning method is how i set mine up and is the method i recommend, it no doubt deviates from PBX's setup instructions.
With paint and air disconnect the cocking noid from the board and pull the bolt back manually to chamber a ball, shoot over a chrono with your finger around 6-8mm behind the bolt. Your looking for 2 things, that the markers shooting 300 FPS and that the bold isn't being blown back when firing.
Adjust your HPR and SON to get 300FPS and adjust the LPR until it's just high enough to hold the bolt forward (it shouldn't hit your finger when firing).
Once you are getting 300FPS and the bolt staying forward you can reconnect the cocking noid.
If you get a leak when increasing the HPR then you have reached the venting pressure of your MQ (They all vary slightly) and will need to lower it by 20 PSI or so and increase your SON. Fitting the white spacer increases the venting pressure but also increases the min working pressure by a similar amount.
Next and probably more important is the Coff time (The time from when the cocking noid is de-energised to when the next ball can be fired) It's easy to get a MQ'd cocker to shoot single balls but takes a bit more effort to get it reliably shooting at high rates of fire.
Do this part with air but no paint, turn the eyes off and set your CON quite low (20ms will be fine).
For this an E2 or Zero-b is perfect as you simply set it to ramp and tune it by ear. What your listening for is a hollow sound as air is coming out the feedneck, keep lowering your Coff until you get this sound then increase it until the hollow sound stops and add 3 to 4ms for safety (If your coff is too low the paint in your feedneck will be blown into your hopper and fill the inside of the hopper into soup, in the case of a halo it even gets through the joints in the shell and covers the board in paint
).
To tune a stock E1 (or E2 to shoot higher than 15BPS) you need someone with exceptionally quick fingers and follow the above method to eliminate the hollow sound.
If you cannot achieve 15BPS or whatever your target speed due to excessively long COFF times then you will have no choice but to up the LPR (to increase ram speed, firstly fit QEV's if you haven't already) and try again.
Don't fall into the trap of trying to tune it far faster than you'll ever shoot as you'll need to run an excessively high LPR pressure to achieve those speeds and loose most of the benefits of the MQ.
Other settings arn't as important but you should set your CON to a time large enough to be able to shoot with the eyes off should you need to (40 to 50ms is fine)
CDEL can usually be set to the min on E2's 4.1ms without any fear of blowback(as the MQ valve is already starting to close before the hammer would have hit the valve on a normal cocker you shouldn't need to mess with CDEL ever)
Recommended settings
SON (Dwell) 3.5 to 4ms (higher if required on E2 and a believe much higher on race frames due to lower board voltage)
Coff 22 to 35ms (22 will only be achieved on exceptionally fast cockers, full bodied cockers will probably be around 26 to 30ms but this is purely down to reciprocating mass, LPR pressure and ram/QEV's) REMEMBER TOO LOW AND YOUR HOPPERS SOUP
CON 40 to 50ms (High enough to load balls with the eye off)
CDEL 4.1ms (Min on E2)
CTO stock or however long you want the bolt to remain back waiting for a ball
EMPTY 1 to 2ms
BALL 4 to 5 ms (you can go lower but risk chopping the last few balls when emptying your hopper)
My settings (remember every cocker is different and i guarantee there is no other like this one)
SON 3.8ms
COFF 22ms (have had it running as low as 16ms but the LPR was at max)
CON 50ms
CDEL 4.1ms
EMPTY 2ms
BALL 4ms
CTO stock whatever that is?
Getting around 1600 shots from a 68/4500 at 280FPS, 2000ish at 260FPS
http://www.pbnation.com/showthread.php?t=1240949
Once setup there is virtually no adjustment or servicing to be done, if you don't mess with anything (especially the LPR, please buy one that requires an allen key to adjust).
The MQ requires greasing every 50 cases or so (100,000 shots
) with shocker lube (i use evolve grease, works just as well).
All you need to alter each day is your velocity via your HPR (No really, just don't mess with anything once it's working
)
What you should get is a perfectly reliable cocker that simply works whenever you need it to. LPR pressure should be much lower than stock but if you tune for speed or have very low reciprocating mass that may not be the case.
At first it feels very different to a normal cocker, as the MQ opens (and closes) so quick it almost feels like it shoots before you pull the trigger when shooting a single ball.
The sound is also completely different, i think due to the MQ closing so quickly that it's already closed before the balls left the barrel. Nearest thing i can think of for sound is a DM4.
There is a reduction in kick due to the missing internals of the lower tube and also the lower LPR pressure but there also seems to be a bit more muzzle rise, i guess due to the ball being accelerated faster but no way to know or prove that.
After having a MQ'd cocker for over a year i wouldn't own another cocker without fitting an MQ, once setup it makes shooting a cocker so painless. You can pull it out of the kit bag any time and know it's going to shoot flawlessly (as long as you haven't messed with it!).
If anyone wants to try an MQ'd cocker mine's never far away at masters 5 man events, although i don't use it as my primary anymore.
AND DON'T MESS ONCE IT'S WORKING
