How to get out more FPS from a WE Scar

[m102404]

If the SCARs weren't so butt ugly I'd be tempted to do a couple of mods to it. There's two ideas that I have to mod the bolt to reduce the impact force and to stretch the life of the hinge plates.

But since they're ugly...I have zero interest in them.

...they make a hell of a racket though and shoot like lasers though...

[Rugger_can]

Originally Posted by m102404

If the SCARs weren't so butt ugly I'd be tempted to do a couple of mods to it. There's two ideas that I have to mod the bolt to reduce the impact force and to stretch the life of the hinge plates.

But since they're ugly...I have zero interest in them.

...they make a hell of a racket though and shoot like lasers though...

To each their own,

The big reason Im attracted to them is their accuracy out of the box. Also they are kinda cool looking.

Like an Minimi and a M4 mated and produced this bastard offspring.

[Sim123456]

Me I find the but stock ugly, wich they had aftermaket one lol

Ok for Co2, fine for me

[Riko]

Originally Posted by m102404

Take a close look at the nozzle. The guide rod screws up into the bottom of the brass base of the nozzle. There's a portion that sticks through. The more that part sticks forward, the further up the float valve will be positioned. More forward = less FPS...further back = more FPS.

are you talking about the stock nozzle? because I thought and read that the stock cannot be adjusted?

thx

[m102404]

yes...even with the stock nozzle you can alter the FPS.

Alter...vs...adjust. Changing the length of rod that sticks through into the nozzle body will change the FPS, but if you grind it, it's a permanent one way change.

So...if the original poster was simply looking for more FPS...then grinding the rod is a solution.

[Riko]

thx!

[Sim123456]

This is what I was seeking, I had 3 rods (one WE, one Ra-Tech and one TSC) so I alter the 3 of them at different lenght. The shortest and so strongest one was my WE rod with stock noozle because there was no rod inside the valve, I cut it fluch and put red loctite to ensure that the noozle stay there. Easiest mod ever to achieve maximum fps, couple to the 505mm inner barrel I had it was pretty amazing. Now I'm modding my M14 for maximum fps, more complicated to do lol

[Riko]

Whats your fps on the scar?
+550?

[Riko]

Originally Posted by m102404

Take a close look at the nozzle. The guide rod screws up into the bottom of the brass base of the nozzle. There's a portion that sticks through. The more that part sticks forward, the further up the float valve will be positioned. More forward = less FPS...further back = more FPS.

You can take the nozzle apart and grind down the stub of the guide rod that protrudes through. Leave 2-3 threads or you might end up with the float valve sitting too far back and it might not slip forward properly into the nozzle tip.

All the way back is pretty close to 600fps with propane at room temp from a 363mm barrel.

hmmmm I find this all interesting, and tomorow my local time I will receive my (2nd) npas kit, so that I tinker with it a bit.
My first npas was installed by my seller and I couldnt see how the valve itself is put together, so now I ordered a second npas so I can "investigate" it all by myself and do as I please with it

I have been searching for your post with this description.
But its still not quite clear for me.

But, its the middle piece you have to shorten a bit?


More precise, its the thread you have to shorten if I read your message correctly, like so?


(remember, at the moment of posting this, I have no npas in hand)
How does shortening the thread help boost the fps?
On that thread sits the valve itself, making it shorter doesnt affect the valve itself I would think?

Can you help me clearify the technical aspect of that rod and how it affects the fps wich comes from the valve.

I don't get it

[Sim123456]

yes...even with the stock nozzle you can alter the FPS.

Exactly, the brand of the rod doesn't affect fps at all. I had 3 rods, the stock WE one, the Ra-Tech one and the TSC one. I did 3 differents cut lengths and my shortest was done on the WE stock one, and it was the strongest fps one I had!

[m102404]

yes...that's the bit. the threaded end screws into the brass base of the nozzle. the furthest back the float valve can sit from the tip of the nozzle is when there's barely anything of that threaded rod poking through the base into the nozzle.

Look at these two rods screwed into their bases...the top one will result in less FPS (because the float valve will sit further forward) and the bottom one will shoot a higher FPS.

[Riko]

ola, thx for that pic, that just confirmed my thoughts
(I am now pm-ing with Sim123456, and I think I got if figured out, but now I am sure)

And I want to be absolutely sure, but the more you screw the nozzle/valve backwards onto the guide rod thread, the more fps right?
If that is correct, in theory I can screw the nozzle all the way till the end of the tread and remove all the remaining thread sticking out?

So I dont understand why I have to leave a bit of thread left?
I dont get that "you might end up with the float valve sitting too far back and it might not slip forward properly into the nozzle tip" - thing

So, why didnt you grind away all the thread on the bottom rod guide of your picture?

[Riko]

Originally Posted by m102404

Look at these two rods screwed into their bases...the top one will result in less FPS (because the float valve will sit further forward) and the bottom one will shoot a higher FPS.

hmmm, shouldnt you be saying than:

the top one will result in less FPS because there is more thread?
and the bottom one will shoot higher FPS because there is less thread?


because, you speak of the placing of the valve, but in both situations the valves are sitting at the same spot, namely at the end of the thread?
and the difference is how many thread there is....

[m102404]

sure...whatever works for you.

The end result that affects the FPS is the position of the float valve within the nozzle. What adjusts it's position is immaterial. It could be different lengths of threaded rod...it could be spacers of different thickness....it could be an adjustable screw that moves a back plate in and out...whatever....does not matter. (NOTE: it does matter if it restricts the flow of gas significantly)

So...really...no. I would describe it exactly as I did because I think it describes it most accurately. If I thought otherwise, I would have described it otherwise.

[Riko]

hmm, okay, I still dont understand it than because on that pics, the both valves sit at the end of the thread
And the only difference I see is that the thread is different....so, its confusing

Question, the adjustment tool for the fps in the npas kit (I assume thats an npas you show or is it the stock valve) what role does that play in this modification?
It becomes irrelevant I assume if you close it for max fps?