G&P M4 upgrade to fps 420

[kudykam]

Thanks for your answers G26.

Originally Posted by G26

Is this your model?
http://www.gp-web.com/en/productspop.php?pid=1535

yes

Originally Posted by G26

PDI210% is approximately around M130 spring rate. Provided if your smithing skills are good enough and you’re running both ends with bearing, you’ll get that figure.

I already have a new spring - Prometheus MS135...

Originally Posted by G26

The spec says it’s 8mm Bearing GB. Just change it to a 8mm bushing. Bearings are a no go for high springrate nor a super high ROF setup.

My GP gun has 7 mm bearing - confirmed, Modify modular ger set for 7mm bear. fit perfectly.

Originally Posted by G26

Get a good brand 11.1v 15c or 20c lipo. Then get the JG M-93 Red Motor. Pair it with stock ratio gearset (reinforced, but stock ratio). Should hit the ROF you’re aiming. Get your AOE, shave the 2nd and 3rd tooth flat to avoid pre-cranking/stripped piston.

I have a new 9,6V battery, and i dont want Li-po. I also have a new GP M160 motor. What is AOE?

Originally Posted by G26

Questions:
Is the “PowerUpgrade all titanium teeth piston” full metal or was it polycarb with metal tooth? Full metal (heavy) pistons aren’t good for high ROF setups.

Polycarb with metal tooth. I dont want too high rof anyway....

[G26]

Originally Posted by kudykam

What is the most suitable piston for my gun? My piston with all metal tooth is lowly getting KO. So I am considering to buy a new one.
I am using spring Prometheus MS135, modify smooth gear set torque and Systema silent cylinder and piston head.
Can I use sorbo pad together with systema silent piston head? (replacing the rubber)
THX

Approx how much BBs u shot with your current setup? If everything's done right, a metal toothed PB should last quite a while. If you experience premature wear on the gears, especially on the early teeths, it's a sign that you'll need better AOE.

If you're using Systema Silent PH, then you'll need to get the sorbopads which is specially meant to be used with the Silent PH.

Originally Posted by kudykam

I already have a new spring - Prometheus MS135...

With a M135 spring, you should be getting at the very minimum 450fps with 0.2g and 363mm barrels, otherwise, you're having major leaks. My stock springed AnK SPR MOD2 shoots at 480fps with a tight bore.

Originally Posted by kudykam

My GP gun has 7 mm bearing - confirmed, Modify modular ger set for 7mm bear. fit perfectly.

Not sure bout the Modular gearsets, but bearings are never meant for heavy springs. Bushing's the way to go.

Originally Posted by kudykam

I have a new 9,6V battery, and i dont want Li-po. I also have a new GP M160 motor. What is AOE?

AOE = Angle Of Engagement
*Note: When you do your AOE mod, make sure you shaved the 2nd and 3rd tooth as well to avoid premature engagement.

For ROFs, it's the combination of motor and voltage/amp supplied. You may have the motor (no exp with the G&P M160), but if the voltage/amps supplied is insufficient, you still don't get the ROF. This is especially true for heavy spring applications. From what I read, there are people that gets pretty good results when they pair two packs of 9.6v parallel. But you'll need a huge battery location for that.

Originally Posted by kudykam

Polycarb with metal tooth. I dont want too high rof anyway....

I've been using the super cheap JG red piston with metal teeth on mine, no problem. Again, it can stand up to M140 spring rate. Ofcourse, with proper mods done to it.

Deepfire polycarb piston body with titanium coated piston tooth is good too, but pricey.

[TokyoSeven]

Best of luck with your project.

If its with in your budget I recommend adding and STS.

http://www.v2fix.com/

[kudykam]

Originally Posted by TokyoSeven

Best of luck with your project.

If its with in your budget I recommend adding and STS.

http://www.v2fix.com/

I already have these...

[kudykam]

About bearings / bushings for gears...
I have Mofidy Modular Smooth gear set TORQUE (21,6:1) for V2 7mm mechabox, but not sure if they use bearings or bushnig, but on the back side of the gears packing is recommendation to use for M120-M140 springs. I suppose Prometheus M135 should be fine...
I mounted it in to my gun yeasterday. It works fine, even my GP M120 motor can handle it without difficulties with sufficient ROF, but I dont like the sound it makes. I assume it is becouse reinforced reverse latch and bevel gear which has more "teeth" then original from gp (had only 2) so it makes clicking sound when I spin the gears with my fingers. Motor does spin it much faster and it makes quite loud and annoying sound. Dose anybody have simmilar experience??

Where can I buy a sorbo pad for systema silent piston head?

[kudykam]

Which reinforced gearbox for 8mm bearings (kanzen ceramic) would you recommend?
I am planning to change gp 7mm gearbox and modify smooth modular gears as I am unhappy with it....

[kudykam]

So I bought Kanzen 8 mm beraings and Modify Torus 8mm gearbox, but unfortunatelly these bearings are much thicker then standard ones and it doesnt fit my lower reciever. I am wasting money for high end airsoft upgrade and I am more and more dissapointed. My gun is still not working because many incompatibility issues.

[Skruface]

Originally Posted by kudykam

So I bought Kanzen 8 mm beraings and Modify Torus 8mm gearbox, but unfortunatelly these bearings are much thicker then standard ones and it doesnt fit my lower reciever. I am wasting money for high end airsoft upgrade and I am more and more dissapointed. My gun is still not working because many incompatibility issues.

MODIFY also makes ceramic 8mm bearings:
http://www.airsoftparts.ca/store2/in...oducts_id=1372

To avoid the incompatibility issues, try to stick to one brand. I know the heartaches of trying to make guns with the best possible parts from a dozen manufacturers; unfortunately it is an exercise in frustration. I stick to MODIFY, Prometheus, or Systema.

[Azathoth]

Originally Posted by kudykam

So I bought Kanzen 8 mm beraings and Modify Torus 8mm gearbox, but unfortunatelly these bearings are much thicker then standard ones and it doesnt fit my lower reciever. I am wasting money for high end airsoft upgrade and I am more and more dissapointed. My gun is still not working because many incompatibility issues.

As Skruface said above.

You cannot buy the "BEST Brand" for each part and put it together and expect it to work. Each manufacturer has different standards and Quality processes and in some cases different design philosophies on "X" part, which may not be 100% compatible with other parts.

I don't like Systema compression components, I prefer modify, prometheus and TM over prometheus. However it's easy to mod and fix the compression system of the gearbox so the brand isnt all that important.

To give you some examples of where I gained some performance by consolidating brands.

I switched my systema air nozzle to prometheus to match my prometheus neo hopup, gained 25 FPS, no tweaks to the air seal on either setup it was good on both setups.

On the P90 switched from a Systema air nozzle to a TM air nozzle and gained 30 FPS with M110 spring.

Go visit airsoftmechanics.com Their is excellent discussion on brand compatability. People running RIOTSC gears will not use modify shells because the bushing/bearing holes are not on TM specs.

I group components into 2 categories. Keep all the components within a working category or system the same brand.

Gears/shell/bearing/bushing
compression system (PH,Cylinder, Cylinder head, nozzle, Tappet, hopup unit)

[kudykam]

I have RIOTSC gears, so which bearings/ bushings are compatible with them?? Kanzen 8 mm ceramic bearings fit without any problems.
Wondering if another investments of 35$ to modify ceramics bearings worth the money.
Maybe steel bushnigs would make the same job? I am not planning to have a high ROF gun. Just slightly stronger spring.
Which b/b would you recommend (thinner than kanzen to fit GP body)?