Vp44 Injector Pop Pressure theory and testing

Smokem said:
Knowing this I would be careful making assumptions as to how something performs unless you are very confident in what it in fact is.
Click to expand...

Understand completely. It would not be finacially logical for me to send the injectors to multiple people to ensure what they are spec'd at just to appease the group.

All I can say is I am happy with the result of the new injectors. The datalogs are there, whatever exact spec the injectors are they are well suited to my setup. I am confident they are higher pop pressure and confident they flow ~20-25% more fuel than my 7 x .009's did. The data logs support the guess on size as well.


Thanks for your insight into the possible issues that come with increasing pop pressure.
 
Figured as much,

time = money and I lazy when it comes to this type of stuff so time = time ^2 haha


I fI was only a rich man
 
the 0-60 times were nearly the same, so close that the winner flip floped back and forth. Again nominal difference in power. If you look at the videos taken the 330 bar injectors are clearly cleaner than the stock bar injectors on a WOT take off. I would have to adjust down my tune by ~%2-%4 to make the stock bar run as clean as the 330 bar.

Cruising duration commands to keep 55 mph were %3 higher with 330 bar suggesting they flow ~%3 less, HOWEVER cruising egt's were down by 50*f with the 330 bar injectors. Running the test from the same light pole to the same light pole.


The very interesting thing is in the lugging spool test. I actually ran this test a few times because I didn't believe the results, but the 330 bar injectors reached 30 psi, from a lugged OD locked TC 41 mph pull, nearly 2 seconds faster. Same stretch of road, same starting MPH, same snap throttle input the 330 bar injectors built boost significantly faster in a lugged situtation. I dont know that I fully believe the data yet on this one, but it is repeatable.

This is what my butt dyno told me as well. The stock bar injectors did not get the turbo moving nearly as fast in a locked tc passing situtation.

next is 350 bar, I expect to see the perks of the 330 bar injectors go away. However I expected to see a more significant difference in power for the stock bar injectors as well.. I dunno.

In no way am I saying higher pop is the gospel nor the right thing to do, but the data is interesting. I think the difference would be much more minor if I wasn't at such as high altitude.
 
dieselbeef said:
so after that the conclusion is that the diff in pop press is negligible. set em correct and be done with it
Click to expand...



So what is “correct pop pressure?” You have some that recommend and use lower than stock pop while others higher.

Point being is that there is no right or wrong here and those of us who are trying something new are not doing so to go against the grain nor are any of us going for all out peak hp. That has been clearly stated from the start of this endeavor.

The blunt opposition, negativity, and just general disrespect is getting quite old and is quite frankly childish. Those of us who are testing this concept are trying to go about it the right way and we are trying to bring light to an area in the community that has never really had much attention. We are doing this by presenting data, videos, experiences, and attempting to make sense out of it all.

There is a wealth of knowledge and a couple of builders who have spoken up through the course of this and we value their experience and opinions. With that stated, we have yet to see data from their findings and they have yet to come forward with anything of value to this conversation.

To be clear, this is not written out of spite nor was it directed at any one person. There is now clear data which proves and disproves some of the old schools of thought. As a community we can learn from this and clear some of the smoke that’s out there.

If you can add to the conversation or help sift through some of this data please do, but otherwise you’re really just wasting your time through opposition.
 
Im just not seeing where it has any gainable effect. I just wanna understand cuz im not seeing where it has made any diff other than a 50 degree diff in cruising egt. maybe im just reading it wrong cuz the numers being said are so small I don't see the reasoning for blowing yer own horn as this is such a great accomplishment

I don't do any rebuilds or swapping of inj for testing purposes so I usually go along with guys that have exp and a good rep. so far that's worked for me..but whatever dude

gains seem miniscule and not really worth chasing in the real world...but like I said I don't know **** about any of it so..carry on kids
 
My opinion here is rather simple, if you are not making comparisons in a test cell with a controlled environment and repeatable load, you are leaving a lot of variables to chance. I can tell you that comparing opening pressure has been engine dyno tested many times in the past, as well as several things I imagine people would overlook.

Don't forget the Bosch opening specification has a purpose, and increasing this value can and at some point will shorten the lifespan of the components.
 
330vvs305luggedpull.PNG.dd8238ef1aa3b994e326af4a1c45f06d.PNG


Like I said above the most noticable difference is the difference in time it takes to get the turbo to 30 psi from a lugged situtation. The 330 bar injectors beat the stock bar to 30 psi in this situtation by nearly 2 seconds. Even if we add a second of error to the log it is still a considerable difference. I ran this test multiple times so I am pretty confident in the numbers. This is a very similar situtation to merging onto the interstate with a trailer, that 3 - 4 shift often lands you at a lower than desired rpm with an auto. I am not going to be reving out the truck with horses in the back, but that lul on the od shift sucks sometimes.

I will agree that %90 of people would never know the difference. However if you were to ask me to choose stock bar or 330 at this point I would choose 330 without a second thought.
 
Smokem said:
My opinion here is rather simple, if you are not making comparisons in a test cell with a controlled environment and repeatable load, you are leaving a lot of variables to chance. I can tell you that comparing opening pressure has been engine dyno tested many times in the past, as well as several things I imagine people would overlook.

Don't forget the Bosch opening specification has a purpose, and increasing this value can and at some point will shorten the lifespan of the components.
Click to expand...

%100 valid points. Trends are about all we can see as the error from a headwind may be enough to scew the entire log.


regardless the data is there grain of salt should be used. I wouldn't call the data invalid due to unknown variables, but it should be looked at with fuzzy math.
 
Last edited:
Smokem said:
My opinion here is rather simple, if you are not making comparisons in a test cell with a controlled environment and repeatable load, you are leaving a lot of variables to chance. I can tell you that comparing opening pressure has been engine dyno tested many times in the past, as well as several things I imagine people would overlook.

Don't forget the Bosch opening specification has a purpose, and increasing this value can and at some point will shorten the lifespan of the components.
Click to expand...

bif what does bosch know?:stab:
 
far as im concerned real world testing on a truck that may not mimic mine at all in its current configuration nullifies any of this data..

its got a VGT TURBO...how is that the same as mine
 
me78569 said:
330vvs305luggedpull.PNG.dd8238ef1aa3b994e326af4a1c45f06d.PNG


I will agree that %90 of people would never know the difference. However if you were to ask me to choose stock bar or 330 at this point I would choose 330 without a second thought.
Click to expand...

The percentage difference from 260 bar to 290 bar for a 12 v injector is 11.5%
The precentage difference from 300 bar to 330 bar in a 24v injector is 10%

This wheel has already been made spun re made broke down and put back together again. Higher pop pressure within reason has many good side effects. Go too far and the side effect become negetive and costly.
 
Why such a problem keeping the rpm where it needs to be while towing? Can't imagine the exhaust note is going to give a horse a heart attack. I was always told these were industrial engines first, and meant to run about 2800rpm, sustained for long periods. Your more likely to break something lugging it, wind it up and run.
 
dieselbeef said:
far as im concerned real world testing on a truck that may not mimic mine at all in its current configuration nullifies any of this data..



its got a VGT TURBO...how is that the same as mine
Click to expand...



Ok we get it, you’re against the idea. Thanks for the input bud.
 
turbo2387 said:
The percentage difference from 260 bar to 290 bar for a 12 v injector is 11.5%

The precentage difference from 300 bar to 330 bar in a 24v injector is 10%



This wheel has already been made spun re made broke down and put back together again. Higher pop pressure within reason has many good side effects. Go too far and the side effect become negetive and costly.
Click to expand...



I am very curious in this data, do you have a thread or data you can pull up on this? Also do you know if they did any comparisons with overall hp and or smoke output?

And on the side effects, have you seen or heard first hand on those effects. I’m guessing it’s probably more directed at tip wear?

Anything helps. Appreciate the input.
 
not against it at all..props for ya for doing it..im just not understanding what is being said is worthwhile gains when in the next part says it 5% or less and a on a truck that may or may not be suited to any one elses application

ill refrain from commementing any further
 
You must log in or register to reply here.
Back
Top