Cyma M4 CQB R Upgrade?

SickMusicMan

Hi all.

I am looking to upgrade my Cyma M4 CQB R and was wondering what is the best ''Drop In'' gearbox out there. I was looking at some of the ULTIMATE or SYSTEMA front wired gearboxes, or would i just be better upgrading the gear box that is in it?

DeBurca

You would be better upgrading your existing gearbox and it would also be cheaper

Can I ask what you wish to achieve by upgrading, greater reliability, a faster rate of fire or just bragging rights

SickMusicMan

DeBurca wrote: »

You would be better upgrading your existing gearbox and it would also be cheaper

Can I ask what you wish to achieve by upgrading, greater reliability, a faster rate of fire or just bragging rights

Cheers for the reply DeBurca

Im looking for more reliability and a faster rate of fire. At the moment the rate of fire out of the box is not great. The fps at the moment is about 280 so i would also like to up that to 320 fps. I will put in a tight bore barrel and maybe a new hop-up unit

DeBurca

SickMusicMan wrote: »

Cheers for the reply DeBurca

Im looking for more reliability and a faster rate of fire. At the moment the rate of fire out of the box is not great. The fps at the moment is about 280 so i would also like to up that to 320 fps. I will put in a tight bore barrel and maybe a new hop-up unit

Well the best upgrade you could do would be the strip and clean the gearbox as the grease used by the maker is a bit on the sticky side, you should do a good shim job before reassembling and greasing the gearbox
Just doing the above will reduce the friction within the box and increase the rate of fire by something in the order of 100-130 BB/min

While the box is apart check the compression and replace the piston O-ring if it needs it

The easiest way to increase the Rate of Fire after having shimmed the gearbox is to fit a High Speed Motor, you should also consider a change to Deans connectors so as to improve the quality of connection between battery and gun

A tight bore barrel is always a good idea as is a change of hop-up rubber the hop-up unit itself is OK and I would not bother to change it

sci-ops

SickMusicMan wrote: »

Cheers for the reply DeBurca

Im looking for more reliability and a faster rate of fire. At the moment the rate of fire out of the box is not great. The fps at the moment is about 280 so i would also like to up that to 320 fps. I will put in a tight bore barrel and maybe a new hop-up unit

Pretty much echo what Deburca has said.

However just to be clear, 280fps with hop on or off? and what weight of bb?

with regards to the o-ring on the piston, you can also try removing it and putting some ptf tape around the piston head, place the o-ring back on and apply some silicon grease. Job done and Bob's your mother's brother.

SickMusicMan

sci-ops wrote: »

SickMusicMan wrote: »

Cheers for the reply DeBurca

Im looking for more reliability and a faster rate of fire. At the moment the rate of fire out of the box is not great. The fps at the moment is about 280 so i would also like to up that to 320 fps. I will put in a tight bore barrel and maybe a new hop-up unit

Pretty much echo what Deburca has said.

However just to be clear, 280fps with hop on or off? and what weight of bb?

with regards to the o-ring on the piston, you can also try removing it and putting some ptf tape around the piston head, place the o-ring back on and apply some silicon grease. Job done and Bob's your mother's brother.

Oh sorry Sci-ops, ya it's 280 fps with hop-up fully off with 0.20g BB's.

Would the stock gears, when reshimed and greased, be able to handle a high speed motor, or should I go for a high speed gear set?

need a aeg

well a better ratio gear set will give faster rof and get low resistance wiring for the best results and all the above

SickMusicMan

need a aeg wrote: »

well a better ratio gear set will give faster rof and get low resistance wiring for the best results and all the above

What would be the better gear sets out there?

Leftyflip

SHS.

SickMusicMan

Cheers for all the help guys

JFAirsofter

CYMA M4 CQBR, i have one, great gun man and the stock internals are brilliant. all you really need to do is a good shim job, adjust the angle of enguagment, and if it was downgraded by replacing the spring then your fine, however if the cylinder was drilled then you should sway out the cylinder and spring, type 3 cylinder and m100 spring should do ya fine

as for the front wiring you can just open the gearbox and redirect the wires, not a big job

also the hop chamber is really good for a stock gun

as for what need an aeg said about low res wiring, its great but doesn't increase ROF, maybe by half a bb per second, but is great for longevity of battery and also go to deans

i've done alot of work to my M4 and i know the thing back to front, so any questions feel free to ask

Inari

JFAirsofter wrote: »

type 3 cylinder and m100 spring should do ya fine

M100? I think that will be pushing the limit. M85's push out .85 - 0.90J in the CYMA M4's, so an M100 would be either very close, or over.

Personally I would recommend using an M85 if you're changing barrels and hop up rubbers. My own CYMA M4 with G&G Green Hop up Rubber & JBU 363mm 6.01 TBB puts out 0.95J with an M85 spring.

JFAirsofter

my own m4 cqb r upgraded to 509mm 6.02mm tbb madbull blue bucking full cylinder and m100 spring shooting 308fps, cyma air nozzle does get a great sealto release the full power, and beside m100 refers to the engery the spring creates been 1 joule, so take into account the loss of air preesure in the seals and o ring i.e. piston head cylinder head and air nozzle, it;s gonna be under 1 joule

Evade

Inari wrote: »

M100? I think that will be pushing the limit. M85's push out .85 - 0.90J in the CYMA M4's, so an M100 would be either very close, or over.

Personally I would recommend using an M85 if you're changing barrels and hop up rubbers. My own CYMA M4 with G&G Green Hop up Rubber & JBU 363mm 6.01 TBB puts out 0.95J with an M85 spring.

This. Barring a poor air seal or very loose bore barrel I've never seen an M100 come in under the limit.

JFAirsofter

now that i think about it
it does also depend on the brand what kind of power they will produce, i have an m100 in my m4 but it does shot shoot bellow 100 meters per sec which and correct me if i'm wrong m100 refers to 100mps lickwise with m90 refers to 90mps, different brands have different quality i.e king arms m100 is about 336fps and systema about 343fps, i got my spring off a tech friend of mine who buys them in bulk, i'm not sure what they are, obviously they just produce a different level of power than others, if you want to be sure then go with m90, but i say m85 is to low power, your losing fps and RANGE!!!

Evade

JFAirsofter wrote: »

but i say m85 is to low power, your losing fps and RANGE!!!

Not if your M85 is producing 315- 320 fps.

JFAirsofter

Evade wrote: »

Not if your M85 is producing 315- 320 fps.

ok whatever about qaulity of the spring, now way an m85 produces 315, if so it shouldn't be an m85 or your chrono is wrong

Inari

JFAirsofter wrote: »

ok whatever about qaulity of the spring, now way an m85 produces 315, if so it shouldn't be an m85 or your chrono is wrong

Springs are not exact - as you pointed out there are variations between brands, as the measuring of a spring is rather subjective; there is no telling what a spring will produce in a given gearbox. It is all guidelines as there is no standard in air seal.

You can improve compression in the cylinder, and avoid loss of air between cylinder head, air nozzle and hop chamber, and improve the seal with tighter bore barrels and softer hop up rubbers. With a perfect air seal, or as close to it as you can attain, then there is absolutely no reason your gearbox should be pulling any more than an M85

Evade

JFAirsofter wrote: »

ok whatever about qaulity of the spring, now way an m85 produces 315, if so it shouldn't be an m85 or your chrono is wrong

I made a mistake I'm using SP85s (and as far as I know SP is roughly equal to M) which supposedly gives you 270 to 290 fps.
If you look at this chart which is missing a few manufacturers because it's a little out of date you'll see how little consistency there is between brands.

Leftyflip

JFAirsofter wrote: »

ok whatever about qaulity of the spring, now way an m85 produces 315, if so it shouldn't be an m85 or your chrono is wrong

Every single custom gearbox I've built for myself or customers have all put out around 305-320fps with an M85, I've had gearboxes where I actually had to cut coils off M85 springs. If you need an M100 to achieve 308fps, you've some serious air leaks somewhere!

FPS =/= Range.
Examples: F2000, 280fps, roughly 60 metres effective range.
VFC 416, 310fps, as above.
G&P Sentry, 325fps, as above.
WE 1911, 260fps, 40metres.
JG Bar-10 315fps, 55metres.

JFAirsofter

honestly lefty, i got my spring off lperrozzi
i thinkin he said m100, but all he said for definate was this will give you the right fps