Standard theory disclaimer here guys. It is just physics and is the basic principles that I operate under. Its more along the lines of this is how I build my truck and if you disagree it don’t matter…. oke: The following information and graphs show concepts and will put you into a ballpark, not guaranteed results. There is no garantee that the computer will even work at the extreme end of the RPM band, but I think it is good for a good ways North of where we are...
I’m going to try and explain why we have been talking about fast injectors and what that means, implies, and what we hope to achieve by advancing this technology. And trust me this is EXACTLY how the rest of the mechanical world keeps advancing and stepping up its game. For all out max power that will ALWAYS remain that way. But for everyone that would like to drive their truck everyday or keep up with the common rail crowd this applies to your truck!
First lets take a look at some 238cc Hybrid injectors with 80% tips. Here is a 3d graph that I generated from flow data collected on a typical set of these injectors:
You can tell that the fuel quantity maxes out as ICP and PW maximize. Nothing particularly spectacular about that. But I then took this data and overlapped that with the FDCS capabilities of the 7.3L PSD. Then I removed some of the high fueling down low on a WOT run and used that information on fuel quantities to generate HP and Torque curve capabilities. This doesn’t take into account any other limitations other than fuel, and can be shifted around by tweaking parameters. Not here to argue the numbers, just show the concepts that the graphs represent.
Looks pretty much exactly like a “typical” hybrid dyno graph except it goes to 6K RPMs right? I ran it out to 6K RPMs to help illustrate our current fueling capabilities and further my point. Notice that the graph peaks at about 2800 RPMs? Pretty familiar huh? By the time you pull enough torque out down low to make your motor live, you will never empty an off the shelf 238cc injector. You can add more power capabilities in down low by adding in more PW below this, but this also ups the torque curve which one of the reasons we all need all these fancy billet rods and junk…..
Compare those HP and TQ curves with many dyno graphs of a PSD with hybrids and you should find them pretty close in concept and shape. Probably similar peak numbers in some instances, a little low for others a little high for the rest.
Now here is the 3d flow graph of a “FAST” 455cc injector:
Yep. That’s a lot more fuel in the same period of time compared to the 238cc hybrids with 80% tips. There is way more going on there than just a tip change – but that is a subject that I won’t discuss in detail.
Now – Take this information and run it through the same process I ran the hybrid data through….
HP and TQ curve:
NOW I’m not here claiming any HP numbers, but this is what the data says. I limited the torque to 1200ft-lbs to show something that might be possible to make live. Note that even doing these limitations the peak of the HP line happens roughly 1000 RPMs higher. The limitations to peak HP are occurring because we passed the point where the max quantity of fuel can be injected. Faster injectors have helped move the curves farther up the RPM band, but they are not fast enough to move the peak any farther up. As the technology continues we will be able to move that peak even farther up the RPM band.
What about the guy that doesn’t want all that fuel, and just wants a good driving truck? What does this mean for you?
Lets take those fast fuel mods and run them on a “standard” 238cc hybrid.
It maxes out the fuel quantities for a much larger portion of the 3d graph simply because there is no more quantity to be had. Lets take that and look at what a theoretical HP and TQ curve:
NOW that’s what I am talking about. That would make one nasty, drivable, and fairly competitive truck in some classes. Torque was held to a level where a “stock” bottom end would live, but that says nothing of balancing, valve train, engine clearances to run RPM, etc…
Verification of data….
Take at look at Nate’s dyno sheet:
Now he is running the injectors that the 455cc flow graph was generated from. While on the dyno he was only using about 1.5-1.6 ms of PW throughout the run based on OBDII data. (Charlie – yes I know… need to verify with a scope… I agree, but it hasn’t happened yet)
Here is the theoretical chart based of off 1.6ms of PW using the flow data from the injectors:
Not perfect, but close enough to say that the data works for peak HP. If I were to massage the torque curve differently then I could get closer there too, but its not worth it for what I would like to show. The truck was not really tuned in and was having some wastegate issues that are now resoved. (I think anyway... Nate would have to confirm that.....)
Take it for what its worth. The data is showing that we are making progress. And I think we have made a lot in recent times, but there is a lot yet to go. I have no idea what happens to the HP/cc ratio does when nitrous is added…. I assume that moves the value up substantially.
Discuss.
I’m going to try and explain why we have been talking about fast injectors and what that means, implies, and what we hope to achieve by advancing this technology. And trust me this is EXACTLY how the rest of the mechanical world keeps advancing and stepping up its game. For all out max power that will ALWAYS remain that way. But for everyone that would like to drive their truck everyday or keep up with the common rail crowd this applies to your truck!
First lets take a look at some 238cc Hybrid injectors with 80% tips. Here is a 3d graph that I generated from flow data collected on a typical set of these injectors:
You can tell that the fuel quantity maxes out as ICP and PW maximize. Nothing particularly spectacular about that. But I then took this data and overlapped that with the FDCS capabilities of the 7.3L PSD. Then I removed some of the high fueling down low on a WOT run and used that information on fuel quantities to generate HP and Torque curve capabilities. This doesn’t take into account any other limitations other than fuel, and can be shifted around by tweaking parameters. Not here to argue the numbers, just show the concepts that the graphs represent.
Looks pretty much exactly like a “typical” hybrid dyno graph except it goes to 6K RPMs right? I ran it out to 6K RPMs to help illustrate our current fueling capabilities and further my point. Notice that the graph peaks at about 2800 RPMs? Pretty familiar huh? By the time you pull enough torque out down low to make your motor live, you will never empty an off the shelf 238cc injector. You can add more power capabilities in down low by adding in more PW below this, but this also ups the torque curve which one of the reasons we all need all these fancy billet rods and junk…..
Compare those HP and TQ curves with many dyno graphs of a PSD with hybrids and you should find them pretty close in concept and shape. Probably similar peak numbers in some instances, a little low for others a little high for the rest.
Now here is the 3d flow graph of a “FAST” 455cc injector:
Yep. That’s a lot more fuel in the same period of time compared to the 238cc hybrids with 80% tips. There is way more going on there than just a tip change – but that is a subject that I won’t discuss in detail.
Now – Take this information and run it through the same process I ran the hybrid data through….
HP and TQ curve:
NOW I’m not here claiming any HP numbers, but this is what the data says. I limited the torque to 1200ft-lbs to show something that might be possible to make live. Note that even doing these limitations the peak of the HP line happens roughly 1000 RPMs higher. The limitations to peak HP are occurring because we passed the point where the max quantity of fuel can be injected. Faster injectors have helped move the curves farther up the RPM band, but they are not fast enough to move the peak any farther up. As the technology continues we will be able to move that peak even farther up the RPM band.
What about the guy that doesn’t want all that fuel, and just wants a good driving truck? What does this mean for you?
Lets take those fast fuel mods and run them on a “standard” 238cc hybrid.
It maxes out the fuel quantities for a much larger portion of the 3d graph simply because there is no more quantity to be had. Lets take that and look at what a theoretical HP and TQ curve:
NOW that’s what I am talking about. That would make one nasty, drivable, and fairly competitive truck in some classes. Torque was held to a level where a “stock” bottom end would live, but that says nothing of balancing, valve train, engine clearances to run RPM, etc…
Verification of data….
Take at look at Nate’s dyno sheet:
Now he is running the injectors that the 455cc flow graph was generated from. While on the dyno he was only using about 1.5-1.6 ms of PW throughout the run based on OBDII data. (Charlie – yes I know… need to verify with a scope… I agree, but it hasn’t happened yet)
Here is the theoretical chart based of off 1.6ms of PW using the flow data from the injectors:
Not perfect, but close enough to say that the data works for peak HP. If I were to massage the torque curve differently then I could get closer there too, but its not worth it for what I would like to show. The truck was not really tuned in and was having some wastegate issues that are now resoved. (I think anyway... Nate would have to confirm that.....)
Take it for what its worth. The data is showing that we are making progress. And I think we have made a lot in recent times, but there is a lot yet to go. I have no idea what happens to the HP/cc ratio does when nitrous is added…. I assume that moves the value up substantially.
Discuss.