KA P90 upgrade parts help

[c.slages]

OK, so I've recently purchased a KA P90. I'm upgrading it pretty heavily and I've done my research, but had some questions about the exact parts I should get as I'm pretty new to this.

First thing is I'm putting in a Prometheus 6.03 EG TBB (407mm). I know it's crazy long for a P90, but I'll have a mock-silencer extension to cover it up.

Now, I know I need a need cylinder for the gearbox to match the barrel length, but does anyone have any recommendations on what one I should go with? Also, should I change out the gearbox itself (considering getting the JG one)?

Also thinking of an R hop, so I'll most likely just get a Prometheus Flat Hop Smooth Bore Hop-up Bucking.

Getting a Lonex A-2 motor, assuming I need short-type for P90, but can someone confirm that it's not the medium?

I guess that's it. If there's any other parts I should be looking at let me know. $ isn't really an issue, just want to build something that is going to perform awesome and that I will want to use for a long time.

Thanks!

[lurkingknight]

Why do you want such a long barrel? Why would you want a longer barrel anyways, aside from slightly longer to accomodate the realistic length suppressor of a p90? What are you trying to get out of it? Should you not care regardless of what anyone says and still choose to go with that length, an end ported or full cylinder will work.

why would you change out the gearbox that's a decent one for a shit one? What's wrong with the shell? Changing shells in addition to mixing manufacturers can make bad manufacturing tolerances worse, and can make your gun perform like shit.

Changing out complete gearboxes will not give you a stable platform to install an R-hop on. You need to check/service/upgrade compression components to eliminate as much air leakage as possible to get the best results from the r-hop.. or any hop up system, even stock.

V6 uses a long motor.

Properly service/upgrade the existing gearbox by checking compression, upgrading what's needed. Don't blindly throw money at it.

Weaknesses in p90s is the trigger contacts, they're not super hard to replace but can be a pain sometimes to source and nothing works quite like original... a basic mosfet can help eliminate the need for that.

Angle of Engagemet fix. If you've managed to read up a little on r-hop, you can manage to read up on AoE. It's a 6$ fix. On second thought, if you've read a little about r-hop, read MORE about it too, find out why it works, how it works and why things should be done certain ways before just throwing money at it blindly.

[c.slages]

Originally Posted by lurkingknight

Why do you want such a long barrel? Why would you want a longer barrel anyways, aside from slightly longer to accomodate the realistic length suppressor of a p90? What are you trying to get out of it? Should you not care regardless of what anyone says and still choose to go with that length, an end ported or full cylinder will work.

Well, I suppose I could go with the full length M4 barrel (360 something?), but if the suppressor is going to be a permanent fixture to cover a longer barrel anyway, I figured I might as well fill it. I realize I won't gain any benefit from this, and that the quality of the material/inner barrel and barrel bore are the important parts.

Originally Posted by lurkingknight

why would you change out the gearbox that's a decent one for a shit one? What's wrong with the shell? Changing shells in addition to mixing manufacturers can make bad manufacturing tolerances worse, and can make your gun perform like shit.

Changing out complete gearboxes will not give you a stable platform to install an R-hop on. You need to check/service/upgrade compression components to eliminate as much air leakage as possible to get the best results from the r-hop.. or any hop up system, even stock.

V6 uses a long motor.

Properly service/upgrade the existing gearbox by checking compression, upgrading what's needed. Don't blindly throw money at it.

OK, I see your point. From what I read the parts on all of these P90s are super interchangeable through manufacturer because they're all pretty much the same. The G&G gearbox from what I've read is supposed to be of better quality, but I suppose I could just shim the existing one super well and see how it works.

Originally Posted by lurkingknight

Weaknesses in p90s is the trigger contacts, they're not super hard to replace but can be a pain sometimes to source and nothing works quite like original... a basic mosfet can help eliminate the need for that.

I've looked into a MOSFET a little, is there one in particular you'd recommend?

Originally Posted by lurkingknight

Angle of Engagemet fix. If you've managed to read up a little on r-hop, you can manage to read up on AoE. It's a 6$ fix. On second thought, if you've read a little about r-hop, read MORE about it too, find out why it works, how it works and why things should be done certain ways before just throwing money at it blindly.

Fixing this as well as installing the r hop are something I would have a professional take care of for me, as they both seem like something I could easily f-up on a first try. What $6 fix are you referring to? From what I've seen fixing the AoE takes a bit of finesse (not to mention a Dremel...)

[kalnaren]

Originally Posted by c.slages

Well, I suppose I could go with the full length M4 barrel (360 something?), but if the suppressor is going to be a permanent fixture to cover a longer barrel anyway, I figured I might as well fill it. I realize I won't gain any benefit from this, and that the quality of the material/inner barrel and barrel bore are the important parts.

I've run suppressors on a P90 with standard barrels. IMO, given the amount of parts you'd need to change it's probably not worth it unless you're doing it for a specific effect.

OK, I see your point. From what I read the parts on all of these P90s are super interchangeable through manufacturer because they're all pretty much the same. The G&G gearbox from what I've read is supposed to be of better quality, but I suppose I could just shim the existing one super well and see how it works.

The problem is different manufacturers make things to different tolerances, and often they'll make subtle changes to the shells or other parts. When the tolerances are tight you can run into fitment issues.

For example, I got an aftermarket reinforced tappet plate for my G36. It wouldn't fit in my gearbox despite being a V3 tappet plate, because of manufacturing differences between Tokyo Marui's V3 mechbox and Classic Army's V3 mechbox.

Other people have had aftermarket mechbox shells physically not fit into the gun, despite being designed for "that type", because of differences in tolerances or ever-so-slight design changes.

My rule of thumb when upgrading a gun is unless you NEED to change a part (for quality or specific upgrade), DON'T.

[lurkingknight]

if you're using gate, probably the ASR or better... nukefet, hamsterfet, anything from extreme-fire.com. You have room to work with in the p90 so the size of it is not much of a concern.

[ThunderCactus]

The stock barrel length is all you need. Longer barrels in no way net better range or accuracy. Ive seen guns get crazy good range and accuracy on 5-9" barrels

[targetGspot]

I used to have an Echo1 p90, sold it to a teammate who still has and loves it. I added a suppressor and, (can't remember exactly) about 2'' longer 6.03 inner barrel. My teams tech shimmed her up perfectly and the thing gained about 10fps and was a whole lot more accurate, but that's all it needed and I wouldn't change a thing. The guy who bought it agrees and won't touch it till something breaks. From what I know, KA puts together a pretty good gun, (only had 1, an AK that was/is a good gun, also in the hands of another teammate). I personally would just do some minor tweaking for now and go nuts if something breaks.

[ThunderCactus]

so your argument is that you changed from a stock barrel, to a 2" longer high quality barrel, and it's the extra 2" that made all the difference?

[wind_comm]

Originally Posted by ThunderCactus

it's the extra 2" that made all the difference?

*coughthatswhatshesaidcough*

[targetGspot]

Just telling you my experience, same chrono two weeks later. 10fps average increase over 10 shots and better accuracy. Shim job made her oh so quiet and smooth but as far as fps and accuracy goes the only change that would make a dif was the barrel. I even used the stock hop. Perhaps it had a better seal when I put it back together combined with the tighter bore for the fps. As far as accuracy goes I know there is a debate about tightbore/widebore, yadda, yadda. I've had great success with tightbore. I've put in a tighter barrel, each time longer than stock ,(1 was a 550mm into an aug if I remember correctly, I was surprised it even worked without making other changes) into 3 different guns, all had increase in fps and accuracy. 1 of them had a new piston done at the same time. 1 of them got a new hop rubber with the barrel. And the p90, just the barrel. I'm not sure why a small fps increase and better accuracy is hard to believe with a barrel swap though?

[ThunderCactus]

It's the fact you went from a stock barrel to a high quality barrel that made the difference. The extra length had nothing to do with it.
Bore and length are mostly inconsequential, only barrel quality matters.
I'd be completely amazed if anyone could spot the difference in accuracy between an Rhopped 6.03 and 6.13 barrel

[targetGspot]

I simply told the guy what I put in the gun, and reported my results. I stated that it was a 6.03 barrel which is typically an upgrade, as you said higher quality barrel. It was 2" longer and tighter than stock. It made an improvement. I'm not sure what the problem is? My point was to let him know that a small change in the barrel will give results, no need to go crazy and get the 407. And gave my opinion on not upgrading the crap out of it until something breaks, then if you have it apart, sure go nuts. On my p90 the barrel swap took all of 2 minutes and without having to touch the gearbox.

[ThunderCactus]

It made an improvement because it was higher quality, not because it was longer or tighter.

[targetGspot]

While I'm sure the better quality was a factor, I'm not convinced that bore and length aren't factors too. Between myself and teammates playing around with our guns, swapping barrels, sometimes something simple like a shorter barrel or longer from the same brand, same bore, has made minor fps differences. (and unscientifically proven accuracy changes) Again my point was simply to dissuade slages from going too crazy and causing himself unnecessary headaches or spending money needlessly. It sounds like He's new to airsoft , or at least to airsoft tech work, and very gung-ho. I think He's better off with small tweaks until He's sure about what he wants from his gun and how to get it.

[ThunderCactus]

I am telling you, as a matter of proven fact, that the length and bore of a given barrel is inconsequential to immediate range and accuracy provided that you have the air pressure and volume to use them.
I've personally seen 650mm 6.01s, 509mm 6.23s, 247mm 6.04s, 363mm 6.10s, and 130mm 6.08s all able to shoot a person at 240ft accurately. Only difference is the shorter and wider barrels do it with less accuracy loss due to fouling.
The most important and critical factors are the bore smoothness and consistency.
The hop rubber will change your range and accuracy far more than the length or bore (again, given you have a setup that can handle the barrel)

The only reason you might see a difference in the performance when swapping barrels is if your barrel is on the long end of your cylinder, and you swap out for one on the short side, or vice versa.

So if you have a cylinder for a 300-380mm barrel, you'll get better performance with a 300mm barrel than a 380mm barrel.
Reason being, you'll get the same fps with a .20, but a heavier BB, like a .28, actually needs more time to accelerate to the end of the barrel, so needs more air volume to maintain compression all the way to the end. This also creates minor joule creep.
So if you're shooting 1.48j on a .20, you'll want to see something like 1.53j+ with a .28. This means you're getting the most efficient use of your barrel.

If you upgrade your barrel to be too long for your cylinder, you'll see a decrease in muzzle energy as well as accuracy. Depending how long you upgrade to, it might not shoot at all.