Originally Posted by nerobro
That's the thing, the dwell on those guns IS NOT static. Among other things that aren't static. such as input pressures, or even set pressures.
First off, regulators aren't perfect. And they have a curve to their recharge. As soon as those guns start firing, their valve chamber, and ram pressures start dropping. Sometimes precipitously. Some of the guns even have some dwell compensation built in, iirc.
Angels dropped their snap ring, and I think they've even dropped the spring. Timmys had no ram retention, still have none. These guns often have FSDO problems, and the "fix" for this is longer dwell on the first shot after a certain amount of time. FSDO, is effectively the same as varying valve open time on the inejctor design. That could not happen.
Now there are other things that vary the dwell on those guns. Stiction in the valve itself, as well as the ram. If the LPR creeps, that could cause a hot shot, or many hot shots. A failing reg seat could cause consistantly hot shots. A failing reg could do the same from the valve chamber side.
None of this could happen with an injector type gun. The "only" failure point that could cause that sort of thing, is the board locking up in such a way as to have the HV power supply turned on, and the fet connecting that to the injector turned on at the same time. It wouldn't take much magic to prevent that from ever happening. (such as using a software SMPS driver from the controller chip. if that locked up, the HV power supply would go away, and the gun would be incapable of actuating the valve)
I understand what you're saying, but what i'm hearing is FUD. You're not familiar with it, so you're fearful of the failure modes. Short of the device actually coming apart at the seams, it would be safer for other players than regulators and solenoid valves.
Something else to keep in mind, the electronic setup would have the same velocity untill it reached the "shutdown" pressure. On guns that use regulators, the velocity varies as the input pressure changes. Regulators have that whole pressure ratio thing. While having two regulators in line does help that, you're still looking at a several psi change over the course of a tank of air.