Lpr Vs Vff

[sIc]

No i dont wanna know which one to get, i just want to know all the differences. Im in an arguement a couple guys and they say the VFF does basically nothing compared to an LPR. Please Explain.

[mipaint]

First lets look at how a stock Impulse works...

The air comes in to the body thru the vertical adapter and up into the Valve chamber. from the valve chamber there is a little transfer passage to the solenoid chamber.

Now lets say we are running at 180 PSI. At this point, you have 180 psi on the valve and 180 psi on the solenoid (which is currently holding the bolt open)

OK- we fire the gun- the solenoid redirects the air to push the hammer forward. Now as soon as we open that valve to the "fire" side the ram starts moving forward-- which quickly creates LOTS more volume to fill. This results in a pressure drop, and more air rushes in FROM THE VALVE to fill the void.

The hammer hit the valve stem, and suddenly we uncork the the bottle and a huge new volume is uncapped. the air russes to fill that volume and the pressure drops way low. Where does all the air come from? mostly from the "storage tank" of air volume in front of the valve. (This is why it is important to have a valve cap that gives you a lot of volume) but it also comes from the solenoid chamber because the valve is pulling air from anywhere it can get it!

OK- now we have the ball starting it way down the barrel, there is very little air pressure left because the valve just directed it all down the barrel, and it time for the solenoid to change the air flow to recocke the bolt. But it needs PRESURE most just when the valve has dumped it all down the barrel. Now ofcourse your air supply is trying to "fill the void"- but it has to fill the whole valve chamber (remember a little bit ago when a big "storage tank" was a good thing- well now it works aginst you because makes that much more volume to fill for the solenoid to get its air)

The result is that the bolt is just a little slugish returning to full cock. In theory the bolt/hammer should recock just as fast as it fires, right? well it dosn't happen that way because the solenoid simply dosn't have enouth pressure to do it. Fourtanly, it gets a little "boost" from the recoil of pushing the ball out the barrel- the "blow back" as many people call it. This is why when you dry fire guns you use more air (no blow back-more work for the solenoid) and often get the bolt sticking forward (not enought engery to push the hammer back far enought to let the valve close)

OK-- so we "FIX" that with a tape worm, right? well a tape worm is nothing but a flow restrictior. The valve can still suck air form the solenoid- but because you have a very long column of air (inside the tape worm tube) it takes longer to "reverse the flow. Ofcourse it also take a lot longer to GET more air as well. end resut, the tape worm "helps" bolt stick, but also creates a bit of drop off at higher cyclic rates.

NOT sounds so good so far, right guys? OK- so now we come up with the "iso mod" (for anyone that dosn't know it, the VFF is an iso mod- it just dosn't have any external air lines) With the Iso mod, we elimate that transfer passage between the valve chamber and the solenoid chamber. then we give the solenoid its own unique air source. End result- the valve can't seal air form the solenoid and when it comes time to recock, you have every bit the same pressure advaible to recock that you had to fire- so the bolt comes bad just as fast as it went forwad.

the end resut is that the action is "more snappy" (which is just a way of discribing the effect of it returning faster) and your not wasting a buck of low pressure air to try to fill the volume tha can be filled very fast with high pressure air.

SO IF THATS SO GOOD, WHY DO WE HAVE LPRs? We guys I hate to break it to you, but MOST of the improvment you get from an LPR is because the LPR is an ISO MOD. What the LPR gives us above that is the ability to use two different pressures.

In case you are new to paintball, there is a good news/bad news connected with air pressure. IN GENERAL higher pressure on a given gun wil give you MORE shot count and Lower pressures will loose shot count. If you have tweeked an Impulse to any extent, you most likly have found that even a STOCK Impulse can run and shoot paint at 300fps at pressure down close to 100 psi. Problem is, if I set up my Impulse to run at 100 psi, I may only get 400-500 shots per fill. I can take that same impulse, reset the dwll to shoot 300 at 180 psi input, and suddenly I get upwards of 100 shots per fill.

Well the solenoid works just fine at around 140 psi- or even lower. So how do we give the solenoid just what it needs but still run the valve up where it can be REAL EFFICENT? Thats you LPR.

WITh the LPR we have already gotton the advanages of the iso mod- but now we can run the valve at very high pressures to also gain shot count. going from a VFF epquiped gun to an LPR epquiped gun (no other changes) will give your the same preformance- but about 100 shots more a fill

hope that helps!

FOM

[Dr J]

That's the long of it.... Here's the short of it.

For the VFF -
- simple
- no maintainance
- keeps pressure/dwell adjustments very simple
- good for efficiency

For the LPR -
- more complicated pressure and dwell adjustment
- awesom for efficiency (especially when paired w/ a new valve)
- requires slightly more maintainance
- also allows the ability to tweak internal pressure to adjust cycling speed/recoil

[Evil Spyder19]

alright so with the 03 rat even though it has VFF would it still help me if i get the LPR?

[mipaint]

Define "help"

More preformance-- NO

More shots per fil--- YES

(last time I write a complete explanition!)

[sIc]

All you needed to say was that last post. :D

[ncpaintballkid]

mipaint, excellent post. That really took care of a lot of questions I had.