mustube
New member
So am I completely wrong in that injection cycles are skipped at all or only partially wrong in that they are controlled by the pcm? I thought I read that in a post here.
Sent from my XT1058 using Tapatalk
Let's do some bench racing
- Thread starter 97BambiBasherPSD
- Start date
So am I completely wrong in that injection cycles are skipped at all or only partially wrong in that they are controlled by the pcm? I thought I read that in a post here.
Sent from my XT1058 using Tapatalk
vanderchevy18
New member
Mustube- I know that when you get into the really large injectors at idle, yes sometimes an injection is skipped just to get it to idle. Intentionally or not. I believe that was brought up by Matt during a thread that was talking about idle quality issues with a 400/400 and hvhf idm.
Here's a cut and dry question that I think a whole lot of people reading this is begging someone to ask.
If you had a stand alone ecu talking directly to the idm, ported oil rail that allows the flow of oil to get in and out quickly enough, a higher ratio injector, separate oil system, and stacked dual inline pumps (4 pumps. Lol!)....... Then is it possible to make it happen? Not even to 6k. Just being able to make power to 5kvwould be a significant enough improvement to make the dead 7.3 platform viable again in the performance world. Hell I personally would invest in a set of heads and oil system like this to make it happen and I'm a nobody in the shadow of the performance competitors. You're talking about an option that turns a $20,000 p-pump build into a $10,000 heui build. It would be a viable commercial option. If..... it were possible.
Here's a cut and dry question that I think a whole lot of people reading this is begging someone to ask.
If you had a stand alone ecu talking directly to the idm, ported oil rail that allows the flow of oil to get in and out quickly enough, a higher ratio injector, separate oil system, and stacked dual inline pumps (4 pumps. Lol!)....... Then is it possible to make it happen? Not even to 6k. Just being able to make power to 5kvwould be a significant enough improvement to make the dead 7.3 platform viable again in the performance world. Hell I personally would invest in a set of heads and oil system like this to make it happen and I'm a nobody in the shadow of the performance competitors. You're talking about an option that turns a $20,000 p-pump build into a $10,000 heui build. It would be a viable commercial option. If..... it were possible.
Last edited:
97BambiBasherPSD
New member
I don't see why that's not possible. At least with the oil side of it. You should be able to port the oil rails somehow along with stacking pumps
Sent from my Pear phone 5 using Tapatalk
Sent from my Pear phone 5 using Tapatalk
Arisley
Moderator
Not possible, at 5K the window is to small to get the oil in and out and get the fuel in and out.
However, I could be 100% wrong also.
However, I could be 100% wrong also.
97BambiBasherPSD
New member
I doubt this would be a viable option but what about external oil rails?
Sent from my Pear phone 5 using Tapatalk
Sent from my Pear phone 5 using Tapatalk
vanderchevy18
New member
I think Andy means in the injector itself.
smokinstroker92
Member
The oil rails can easily be ported that is not the problem its the injectors themselves. Getting the oil in then refilling with fuel in a time window to inject a large enough amount of fuel at 5k to actually make power
Sent from my DROID RAZR HD using Tapatalk
Sent from my DROID RAZR HD using Tapatalk
smokinstroker92
Member
Also you would have to figure a way to return the oil from the injectors if you were trying to build a separate oil system for the injection.
Hotrodtractor helped design and build a set of lower ratio injectors that will flow lots of fuel but if I remember correctly said the resolution wasn't there and need more precise seloniods to operate them
Sent from my DROID RAZR HD using Tapatalk
Hotrodtractor helped design and build a set of lower ratio injectors that will flow lots of fuel but if I remember correctly said the resolution wasn't there and need more precise seloniods to operate them
Sent from my DROID RAZR HD using Tapatalk
Hotrodtractor
Moderator
Actually there are a couple of tweaks that can improve control resolution of those big injectors down low. To the best of my knowledge no one is doing it... but it has been done in basic form on some bench testing.
You don't need a stand alone ECU. You don't need a ported oil rail. You DEFINITELY don't need higher ratio injectors. You don't need 4 oil pumps. You need to better utilize the oil that you have and stretch it farther that you are currently.
You need modifications to the injectors. Modifications to your HPOPs. A couple of sensors and some tuning to make it all work correctly.
It still will not make the 7.3 a competitive platform when it comes to power production unless you live in an area where they haven't caught up to the power levels that are currently possible in other platforms.
smokinstroker92
Member
PsdPullerJr
Member
Was searching around for info on cams, came across this and thought I would share. More good injector info... http://powerstrokearmy.com/forums/showthread.php?t=2453&highlight=Cams
DocBar
New member
You need to change your username to Icraponhearts!!!!LOL
Hotrodtractor
Moderator
Injectors are mechanical systems that must abide by the laws of physics. If you want greater control resolution in a particular area you must "flatten" out that particular area on a flow map.
Take these 238 hybrids from testing way back in the day.... probably 5 years ago now:
Now we apply some modifications that allow them to inject fuel faster - ie a higher injection flow rate allowing for them to climb higher in the RPM band.
Notice how the flow rate increased pretty healthily during "normal" idle parameters? This high flow rate is what causes a bad idle that is sometimes associated with large injectors. There just is not enough resolution at those low ICP figures to be able to control the flow rate fine enough to smooth out the idle.
By doing some changes you can end up with something more like this:
Notice now the area of the map where you would associate with idle and low throttle situations has a decidedly lower flow rate with only marginally effecting the areas of max flow. These changes essentially resist flow at lower ICP numbers that allow you to have greater control. There are a multitude of things that can get this desired effect - this graph was generated with just a couple of minor changes, some of it off the shelf, and some of it uniquely custom from my bag of tricks. Further testing would be required to get the right balance of control resolution and fuel flow.
vanderchevy18
New member
I would love to try a set of those. In 400/400's of course. 
I would love to try a set of those. In 400/400's of course.
Hrt doesnt mess with them. He has big nozzles and even larger injector capacity to play with.
elrodalexander73
Member
What most I think fail to understand is that Double Overtime was an engine built by TFS performance... Not an engine any of us will build to that level, everything was tweaked, yeah the mechanical Vpump really brought it to life, but the CNC ported heads and the valve train to get it to 6500 rpm is what brought it to life.. With out head flow they are dead engines at that level. Everything from billet rockers CNC machined (TFS is known for winning, "winning" prostock engines) custom billet cam, to a balanced bottom end, and 13-1 J.E one off pistons. Mechanical injection definitely played a huge part.. But in the mod class before the two turbo limit the 7.3 had one significant advantage (we are always going to struggle with in the lower classes 2.6/2.8) and that is displacement. You can throw 1100cc fuel on 8 cylinders and push more air through 8 cylinders with 60 more cubes and always make more power period.. As with a 2.6 charger or even a 2.8 your air flow is limited, very limited, and even with 400/400s its hard to use all of the fuel.. A 5.9 can use all the air more effiecently with a smaller turbo be cause they have less volume to fill. A 2.6 5.9 can make 1200hp with a small charger at VERY HIGH RPM because the charger can fill 6 cylinders much quicker than a 7.3, resulting in more useable power... Put a P'Pump on a 2.6 motor and you'll be suprised if you break 1200hp.. We are pulling in classes with limited air flow, against engines that are smaller with indeed faster fuel systems, but again, air flow plays a huge part. Its the same reason the 3406b will stomp a KT cummins in hot stock with a 4in inducer regulated charger...
