Dye DFF-20 Lazarus Valve

[SR_matt]

I’ve seen a bit of range on where people say to set it but 180 seems to be the general starting point. Angry recommends 200 to start when using the JK hammer and spring but it seems like even on a lot of his setups he ends up at 180.

[BrickHaus]

It will in some manner. If you get to too high of a pressure, I have seen submarining.

I preset my reg to 200, and attempted to use the igv to adjust velocity. After 7 turns on the igv, I reset it to flush, and backed my reg off 1/4 turn. Then tried the ivg again. About 4 turns on the IVG hit velocity. It's very anecdotal data, but that tells me there is a sweet spot for these.

[Toestr]

The reg won't sweetspot since it's balanced.

[Jordan]

Are you guys sweetspotting the reg and adjusting velocity via the IVG, or using the reg/OP to adjust?

I've only set up oldschool 9/16 valves, and was unsure if there was a difference with the Lazarus.

[flyweightnate]

The backpressure will shorten the dwell, improving efficiency as mentioned above, and the barrel is pressurized until the gas escapes at the ports/ muzzle so no worries there.

There may be a slight change in dwell depending on where the ball rests in the chamber/ barrel, since it will affect the amount of volume that initial pulse fills, so I'd think underbores and detents will be important if you're chasing maximum consistency. I tested something with similar behavior back in college and I could get wildly different dwell by removing the barrel. This is obviously far more refined than my build, but still... it's an impact.

[tyronejk]

There's no negative pressure developed behind a paintball with an underbore or with this valve.

This valve works by using the pressure pulse from firing to help close the valve. So both this valve and traditional valves require the ram/hammer to push against the valve spring + chamber pressure to open the valve. But traditional valves have only the valve spring to close the valve while the Laz valve has the valve spring + firing pressure pulse to close the valve.

[SR_matt]

Breach sensing has more to do with efficiency than anything else. Just because of the nature of balanced systems they don't close very fast (less closing bias), so the back pressure from the shot helps close the valve faster. You get the benefit of a valve that is easy to open without the drawback of a wasteful mechanical over-dwelling. Also the old Bob Long valves that the Lazarus is based off of would sometimes get a vacuum within the cap causing issues.

I could see that. basically an under bore causing negative pressure to develop as the ball moves down the barrel, or even just Venturi effect of the air (like suction timing). I assume as long as you get it tuned to a point where the valve closes before you can develop any negative pressure in the breach you wont have that issue... but I am not an engineer just a technical nerd.

[Frmrspec]

Just had a question pop into my head. With the "breach sensing" (or what ever marketing term they are using), does that alone help to make shot to shot velocity more consistent?

Breach sensing has more to do with efficiency than anything else. Just because of the nature of balanced systems they don't close very fast (less closing bias), so the back pressure from the shot helps close the valve faster. You get the benefit of a valve that is easy to open without the drawback of a wasteful mechanical over-dwelling. Also the old Bob Long valves that the Lazarus is based off of would sometimes get a vacuum within the cap causing issues.

[latches109]

I have both stock and LAZ valves shooting very consistent. Zero difference there.

[SR_matt]

Just had a question pop into my head. With the "breach sensing" (or what ever marketing term they are using), does that alone help to make shot to shot velocity more consistent? We know that shooting an over bore vs and underbore usually will change the actual velocity with out changing any other factors, but if you are undbored the breach pressure I assume ends up higher (thus closing the valve faster) and over bore lower (thus closing the valve slower.

or did I just miss this already being discussed on this thread?

[imped4now]

*Spread* misinformation? Incorrect.

I'm a 15 year automotive engineer man.

I have used U-Cups in a handful of non-standard paintball cases, such as Insight/Onslaught shutoff and ram 010 seals (which I saw a small but measurable decrease in efficiency), Dye Fuse valve seal and one-way ram sail seals (Infinity Legend). In early Laz testing, I ran both the U-Cup and an O-Ring there and while the difference was within margin of error, it was still an observation, hence "anecdotally." I'd love to test a Force with certain U-Cups swapped out in favor of O-Rings, but never got around to that when I had the chance. I've always speculated that there was dynamic leakage occurring within that system, hence the poor efficiency results.

To your point, U-Cup usage does require different gland design than O-Ring usage. Having seen miscommunication between Dye's design and manufacturing teams before (DLS), perhaps that's the case here. Without performing a deep dive, I don't have that answer.

[latches109]

imped4now You spread so much miss-information. This is a Dye engineering design failure and manufacturing failure - Not a materials failure. U-cups seal very well and are excellent choice for many mission critical applications. Aerospace, automotive, aviation all use this seal design.

[MrBarraclough]

superman was that directed at me or at BrickHaus?

[imped4now]

Anecdotally, I believe U-Cups are not ideal for efficiency in most paintball applications. Reliable sealing > a slight reduction in friction.

[superman]

Have you tried sweet spotting the reg? does it actually peak at 250? are you using the stock main spring? the inception springs are longer.