Injection pressure idea
- Thread starter Matrix37495
- Start date
Ididriver
Full Access Member
Gotcha
Besides the fact that it would wear glow plugs out faster. How would the higher pressure affect fuel mileage,drivability,idle racket etc.
Besides the fact that it would wear glow plugs out faster. How would the higher pressure affect fuel mileage,drivability,idle racket etc.
Matrix37495
The Amish Wolfman
Well, the way i understand it, the higher pressure takes longer to build, retarding the timing hence advancing the pump. I don't understand why that would wear out the glow plugs because the combustion event should be occurring at the same time as it did before.
I am curious what the timing would need to be set at in °BTDC (pulse method is the only one available to me).
I am curious what the timing would need to be set at in °BTDC (pulse method is the only one available to me).
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dyoung14
Is getting worn out
My timing didnt have to be set as high as i put it, i did it for more power and boost, the rattle is plenty acceptable, and it gives it a different sound i liked it, with mine advanced all the way when i flored it accelarating it would rattle hard until the turbo lit then you were gone,
Mine were BB codes shimmed to 2300
One thing i do know for sure is my boost doesnt build the same and i have alot less smoke then when i had my injectors, i wish i still had them
Mine were BB codes shimmed to 2300
One thing i do know for sure is my boost doesnt build the same and i have alot less smoke then when i had my injectors, i wish i still had them
Matrix37495
The Amish Wolfman
Why did you take them out David? You said your timing was advanced more than needed, did this cause any glow plug problems?
Matrix37495
The Amish Wolfman
Got a couple of *** that could pertain to our thread here.
EDIT: Removed 2nd PM. It would just start more controversy than i want in here. He's claiming that the best timing would be 10-12°BTDC.
These are direct quotes, so don't jump me about content please....
1BadB2 said:
EDIT: Removed 2nd PM. It would just start more controversy than i want in here. He's claiming that the best timing would be 10-12°BTDC.
These are direct quotes, so don't jump me about content please....
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Black dawg
Registered User
just a wild ass guess, but if the higher pop pressure atomizes that much better, any retardation of the injection timing should be overcome by less ignition lag.
MidnightBlade
Shiftin' Smooth
Mel, Russ, and icanfixall had a nice conversation with me last year about pop pressure and the good and bad.
The ideal range is between 2200-1800 PSI within 50 PSI of each other. The higher the pop pressure the more wear it will be putting into the IP. Is the tiny power gainworth having to replace the IP every 50K? I have mine set at 2000 Psi and don't really notice any difference between them and my old set. My timing is at 9.5* set by Mel. I personally can't speak on the power/mileage aspect because I changed more than one variable at a time. Yes my mileage and power went up compared to the original 150K set that came out along with the stock IP. My gains could have came from the rebuilt pump (turned up 3 flats before I even put it in the truck) the extra fuel from turning it up, the fresh injectors, or the higher pop pressure. It's all just a guess in my case, my vote is for a properly matched set around 1800-1900, From what I have dug up these seem to be the best comprimise betwwen mileage and pump life.
IDIDriver-I have one problem with your plan. Cutting the tips off of your GP's would also be changing the volume inside the cylinder thus lowering compression. This also would be changing more than one variable. Unless, however, you installed the modified GP's for your baseline test and keep them installed for the high pop test.
The ideal range is between 2200-1800 PSI within 50 PSI of each other. The higher the pop pressure the more wear it will be putting into the IP. Is the tiny power gainworth having to replace the IP every 50K? I have mine set at 2000 Psi and don't really notice any difference between them and my old set. My timing is at 9.5* set by Mel. I personally can't speak on the power/mileage aspect because I changed more than one variable at a time. Yes my mileage and power went up compared to the original 150K set that came out along with the stock IP. My gains could have came from the rebuilt pump (turned up 3 flats before I even put it in the truck) the extra fuel from turning it up, the fresh injectors, or the higher pop pressure. It's all just a guess in my case, my vote is for a properly matched set around 1800-1900, From what I have dug up these seem to be the best comprimise betwwen mileage and pump life.
IDIDriver-I have one problem with your plan. Cutting the tips off of your GP's would also be changing the volume inside the cylinder thus lowering compression. This also would be changing more than one variable. Unless, however, you installed the modified GP's for your baseline test and keep them installed for the high pop test.
Matrix37495
The Amish Wolfman
These would be matched as close as we can reasonably get them.
Sounds like we should shoot for 2000-2100 as a test with 9.5° BTDC. The IP that will go into my truck has about 1k on a rebuild.
Right now this is still in the "what if" stage. Hoping to move it to the next step soon (building a pop tester).
Sounds like we should shoot for 2000-2100 as a test with 9.5° BTDC. The IP that will go into my truck has about 1k on a rebuild.
Right now this is still in the "what if" stage. Hoping to move it to the next step soon (building a pop tester).
93cc7.3
needs turbo power
This is going to go completlely off the wall here but what would happen taking the precup out and putting in di injectors I know this is probably very flawed but I would like to learn why the heads couldn't be made into di by doing so
icanfixall
Official GMM hand model
Removing the precups will require custom precup incerts. Then your going to need a custom lengthened nozzle to reach into the new combustion chamger for direct injection. Keeping the longer nozzles cool will be an issue. Nice idea too...
When developing the Moose Misters, a lot of thought was put into the pop presure question, and what we determined is that there is no significant difference in atomization when dealing with only a 300 PSI range of usable values. If you watched the Moose Mister video, you can see the difference in atomization between standard injectors and the Moose Misters. Most of that difference comes in the nozzle design, and not in the pop presure. Then you have different schools of thought about how performance is effected by atomization in an IDI. The DPS school of thought is that atomization doesn't matter. Torque is increased by pooling the fuel on the precup walls which slows the burn and makes it last longer. The sacrifice there is that you can get an incomplete burn and more smoke. The Moose Mister school of thought is that a complete instant burn will get you more grunt at lower RPM's and built better boost by giving you a wicked clean burn. Both injectors pop around the same, and truth be told pop presures seldom hold at their maximums for more than 10 or 20 thousand miles anyway. DI injectors often atomize in multiple directions, aiming to squirt into the space horizontally between the head and the piston. We can't get a nozzle down into that space, so spraying against the precup walls doesn't buy you anything.
93cc7.3
needs turbo power
Removing the precups will require custom precup incerts. Then your going to need a custom lengthened nozzle to reach into the new combustion chamger for direct injection. Keeping the longer nozzles cool will be an issue. Nice idea too...
Ok that is the info I was looking for so we are looking at heavy machine work ... if one did want to venture down this path what about a totally diffrent injector with a much longer body thus keeping the nozzel short and less prone to heat issues clearly this is a question of pocket book depth and machinest skil
Interesting Quote from 1BadB2
I just wonder where he gets all that extra pressure from on an IDI IP. Me thinks he's confused between an IDI injector and a PSD injector. An IDI injector is filled with a certain amount of fluid, when it's time to release that fluid into the precup, the IP builds and releases thru it's rotation to the proper port that pressure to the point of whatever the injector (pop pressure) is set at. There is nothing in an IDI injector to increase the residual fluid pressure before it's time to "POP" goes the weasle. That's the way I see it.
Some PSD injectors can reach a "POP" pressure as high as 40,000 PSI, won't get into that tho.
I just wonder where he gets all that extra pressure from on an IDI IP. Me thinks he's confused between an IDI injector and a PSD injector. An IDI injector is filled with a certain amount of fluid, when it's time to release that fluid into the precup, the IP builds and releases thru it's rotation to the proper port that pressure to the point of whatever the injector (pop pressure) is set at. There is nothing in an IDI injector to increase the residual fluid pressure before it's time to "POP" goes the weasle. That's the way I see it.
Some PSD injectors can reach a "POP" pressure as high as 40,000 PSI, won't get into that tho.
FordGuy100
Registered User
Pop pressure is just the pressure that the injector is set to "open" at. The DB2 pumps are capible of much more pressure than the pop pressure.
Just think, if a DB2 pump only put out 1800psi, and an injector was set to pop at 1800psi...the pump would push the fuel, the injector would open up, and would imediatly close as the pressure in the injector line would fall (Like when you have a garden hose on all the way, you crimp the hose to stop the flow, and then release it it flows like crazy for a split second and then falls to its normal rate) as the injector opened, making the pressure in the line going to the injector fall below 1800psi, and the injector would close as the spring would overcome the pressure and stop flow.
Correct me if I'm wrong.
Just think, if a DB2 pump only put out 1800psi, and an injector was set to pop at 1800psi...the pump would push the fuel, the injector would open up, and would imediatly close as the pressure in the injector line would fall (Like when you have a garden hose on all the way, you crimp the hose to stop the flow, and then release it it flows like crazy for a split second and then falls to its normal rate) as the injector opened, making the pressure in the line going to the injector fall below 1800psi, and the injector would close as the spring would overcome the pressure and stop flow.
Correct me if I'm wrong.
