found this from R&D. Seems to makes sense to me.
Not all of the fuel is combusted inside of the pre-chamber as most would assume, only about 40% (Or less depending on injector setup) or so is, and the rest is pushed out into the mixing cups on top of the piston where it is ignited and transformed into an expanding gas, and therefore energy to the crank. Now there is several aspects on how fuel reacts to the compressed air in the Pre-chamber and squish area above the piston, with the biggest ones being 1) Spray pattern 2) Pop pressure and 3) Fuel volume. Now most IDI'rs would seem to think that the most fine spray pattern would be the best because it equates into the most burned fuel, which while being true, it does equate into the most burned fuel, its not the best in every situation. The problem is, if the spray is too fine, it can ignite more fuel in the Pre-chamber which leads to energy loss in both the walls of the pre-chamber, and a slower transfer of the remaining fuel (especially at higher RPM's) into the cylinder to be directly applied to the top of the piston. This is typically the reason why something like a moose mister runs smoother than a stock or DPS injector, is because the energy is applied to the top of the piston at a slower and smoother rate (Thats the whole reason IDI was developed). Now something like a DPS injector, where the pintles are removed and ground to provide more volume (well get to that later), and I dont know if Ken developed them is way, or if it was just a side effect of wanting to increase the volume of flow, but the spray pattern is what some IDI'rs look at as abysmal. Its just a stream of fuel into the Pre-chamber, and what this actually does dynamically, is decrease the surface area of the fuel droplets, allowing for less contact with hot air molecules, to the point that more fuel is pushed out of the pre-chamber where it is atomized and combusted on top of the piston. This process happens faster than the finely atomized fuel because the fuel is atomized over a bigger area (Cylinder vs. Pre-chamber). Now the problem with this, is if you dont have enough air in the cylinder, the fuel isnt adequately atomized and you tend to get a smokey situation, which is the biggest complaint of the DPS stuff. If you actually plan on stuffing a significant amount of air into your engine, the DPS stuff is probably a better choice, if you want a smooth running truck that doesnt smoke and that you dont plan on running a lot of boost in, something like moose misters would probably be a better choice. Now onto number 2. Pop pressure is essentially the pressure that your injectors start to spray fuel. The effectiveness of pop pressure is going to depend on your nozzles and spray pattern, something like a DPS injector is going to want more pop pressure to prevent dribbling (The negative extent of what I explained above) while something with a finer spray patter is going to want a little less to extend the timing of the spray. And 3, if your moving a lot more fuel, your going to need the extra flow, I know the DPS stuff allows for more fuel flow over stock because of the removal of the pintle, I have no idea if Mels stuff has any other provision for increasing fuel volume, and certainly stock is stock.
I too am wondering why the need for this type of injector.
