At the advice of @jlbayes I decided to post up some questions for the injector builders to answer. I don't know what kind of response I will get but it is worth a shot.
I have been wondering for awhile what the result of increasing pop pressure would be. there has been a lot of " not worth it" "lope idle" " stalling in gear" talk, but never much beyond "don't do it because I know best" with no real explination as to why.
There is also a lot of thoughts from the other side saying that increased pop pressure will help atomize fuel better on big injectors. They theory makes sense, if you increase the hole size but keep the pressure static then you in theory loose the ablity to atomize fuel as efficently. I have experienced this direcetly as the first set of 7 x .009's I got from DFI were set at ppump pressures. Those things smoked like crazy regardless of situtation. I sent them back to him and got them repoped and that resolved the smoke issues.
So I made the jump from some 7 x .009's from DFI, I was very happy with them, to a set of 7 x .012's vco at 330 bar from DAP.
I wanted to know if I could control the injectors well enough to make them %100 dd friendly, tow friendly, and emissions friendly.
I have been running them now for ~ 1 week. I have the Quadzilla tuned to remove nearly all the smoke in all situtations ( to the point where I will pass emissions no prob). I thought I would have to offset timing to compenstate for the later pop pressure, but I see no reason to at this point. I don't think the extra 20-30 bar is effecting timing near as much as people say it would. you can sort of feel the difference until ~1200 rpm, but beyond that you would never know the difference.
Here's a WOT take off to show the resulting tuning, there are plenty more videos and datalogs of the videos, but I don't see a need to junk up the thread.
7 x .012 330 bar Quadzilla Tuning - YouTube
What I have found is that I am able to throw a good bit more fuel at the truck with the 7 x .012's offidle than I was able to with the 7 x .009's without exceeding stoic limits for haze turning into smoke. I am forced to believe that per mm3 of fuel injected the bigher pop pressure injectors are atomizing fuel more efficently.
So the main question I have is, given what I have found so far, what prevents the builders from setting pop pressure higher? If you are a builder, have you actually tested the results of setting injectors at a higher pop pressure? I can't believe increasing pop pressure causes stress on the pump considering the vp44 can build ~1600 bar worth of pressure.
Comments? Insights? Insults? Anything more than "just get better injectors"?
I have been wondering for awhile what the result of increasing pop pressure would be. there has been a lot of " not worth it" "lope idle" " stalling in gear" talk, but never much beyond "don't do it because I know best" with no real explination as to why.
There is also a lot of thoughts from the other side saying that increased pop pressure will help atomize fuel better on big injectors. They theory makes sense, if you increase the hole size but keep the pressure static then you in theory loose the ablity to atomize fuel as efficently. I have experienced this direcetly as the first set of 7 x .009's I got from DFI were set at ppump pressures. Those things smoked like crazy regardless of situtation. I sent them back to him and got them repoped and that resolved the smoke issues.
So I made the jump from some 7 x .009's from DFI, I was very happy with them, to a set of 7 x .012's vco at 330 bar from DAP.
I wanted to know if I could control the injectors well enough to make them %100 dd friendly, tow friendly, and emissions friendly.
I have been running them now for ~ 1 week. I have the Quadzilla tuned to remove nearly all the smoke in all situtations ( to the point where I will pass emissions no prob). I thought I would have to offset timing to compenstate for the later pop pressure, but I see no reason to at this point. I don't think the extra 20-30 bar is effecting timing near as much as people say it would. you can sort of feel the difference until ~1200 rpm, but beyond that you would never know the difference.
Here's a WOT take off to show the resulting tuning, there are plenty more videos and datalogs of the videos, but I don't see a need to junk up the thread.
7 x .012 330 bar Quadzilla Tuning - YouTube
What I have found is that I am able to throw a good bit more fuel at the truck with the 7 x .012's offidle than I was able to with the 7 x .009's without exceeding stoic limits for haze turning into smoke. I am forced to believe that per mm3 of fuel injected the bigher pop pressure injectors are atomizing fuel more efficently.
So the main question I have is, given what I have found so far, what prevents the builders from setting pop pressure higher? If you are a builder, have you actually tested the results of setting injectors at a higher pop pressure? I can't believe increasing pop pressure causes stress on the pump considering the vp44 can build ~1600 bar worth of pressure.
Comments? Insights? Insults? Anything more than "just get better injectors"?
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