HPO health

[eabrust]

Just got Autoenginuity and having fun playing around with it. Great software/hardware. took about 2 minutes of playing to do cylinder contribution test w/ plot, and also verify all other sensors I was worried about are still working....

Anyhow, my truck has always felt somewhat like a bit of a dog and doesn't get the sort of mileage others seem to report, even tuned, so just looking to see if I can't pick out something causing it besides the strategy I have (VXCF7), Starting w/ the HPO system.

It has 8 new stock injectors, Gryphon w/ 80 and 100 HP tunes, and a non-IH strategy FICM tune. Always fires up great and idles fine now (even now that mornings are 20*F or so), and no issues w/ hot starts. I grabbed the desired ICP, actual ICP, and IPR DC in a few tunes, and am just looking for a little feedback if this seems to look good, or if it would indicate a minor HPO leak somewhere. Most my searching via google shows people saying that IPR DC should be ~15% at idle, I see 23%, but the actual ICP always reaches desired, so does that mean all is good?

These are the sort of numbers I see:

Idle
ICP Desired 584.6
Act ICP 583.51
IPR DC 23.83

WOT 80 DD
ICP Desired 1740.3
Act ICP 1744.87
IPR DC 59.77

WOT 100 Perf
ICP Desired 3176.5
Act ICP 3024.64
IPR DC 75.39


The ICP desired are the maximum values I seem to be able to get when flooring it in a given tune. This look good?


Thanks for any input as to if the ICP vs IPR DC seem to be indicating a problem or not.

Eric

[eabrust]

To partially self answer, in the 6.0 coffee book (6.0 bible as it goes by on the web), in the back section of 'Performance Diagnostics', I've found a limit of 30% max IPR DC at idle of 670 rpm.

Can anyone else say what they typically see for IPR DC at idle...? Just trying to compare and see if just because I'm still within the 'limit', does my truck use a much higher IPR DC than is typical?

thanks,
eric

[Power Hungry]

IPR DC at idle is usually anywhere from 15% to 25% in order to maintain the ~575 psi of ICP. IPR demand will go up as the needs of the fuel system increase. The tow big things to watch for are that your Desired ICP and Actual ICP are pretty close (usually within 5%) and that IPR doesn't exceed 85%. If IPR goes over 85%, the pump is not able to keep up with the oil demands of the fuel system.

One thing to keep in mind... It's okay if the desired and actual values are a little off as long as the IPR is still able to compensate. The is a gain value for the IPR that will self adjust the IPR to achieve desired ICP, but it's pretty slow. It can take up to a few seconds for the ICP to stabilize at the desired values, which is perfectly normal. As long as the IPR DC hasn't topped out at 85%, it can self-adjust.

The only other thing I'm curious about is why your ICP values in the 80HP are only around 1750 at WOT. At what RPM were these values pulled? ICP (both desired and actual) will increase with RPM so I'm assuming that those values are from a sub-1800 RPM sample.

I hope this helps.

[eabrust]

Bill,

First of all, shame on you for not taking a proper vacation from your work. But as a fellow engineer, I sort of understand not being able to just 'let it go....' Now go play with your kids before Corey kicks yer rear!!

I went and double checked the logs, all the ICP pressures at WOT that I quoted above are at engine rpm of ~2700 rpm (tried matching conditions).

Not sure what is normal or what you expect to see out of the 80hp tune wrt ICP, but 1730 psi is where it stops. I've included a plot attached, which pretty clearly shows it hits a plateau and stops. One thing I'm curious, do the tunes affect the pedal sensitivity (throttle % vs pedal position)? the 100 tune seems to give higher throttle % for about the same push on the pedal (using a non calibrated foot that is).

The truck drives great, and I use the 80HP tune almost exclusively as the daily driver program. so no real complaints, just trying to trouble shoot/learn a little. Sometimes the truck just feels weak , but when it feels weak, it is also weak in the 100 tune also, which is what got me looking at the HPO pressures. Will keep playing though!

Thanks for the response, appreciate it!
Eric

[Power Hungry]

I'm puttering around early in the morning while I have my coffee, so I'm not really intruding on my vacation.

I looked over the graphs a bit and I'll have to compare them against the ICP tables in your files. It does seem odd that you're barely hitting 2000 PSI most of the time and it makes me wonder if the scaling in the AE software might be off. Based on the ICP Desired tables, at full throttle above 2400 RPM the ICP output should be be at LEAST 3200 PSI if not more. I get the feeling something is a bit screwy. One thing that is good is that your Desired and Actual ICP values track very closely together. This is a good indication that your HPOP may be just fine.

I have a few datalogs from Brad's truck on the server at home and I'll have to get a look and see how closely they compare with what you're seeing. This way we can determine if you're actually having an issue or if you're chasing a ghost.

[eabrust]

Thanks again Bill,

Appreciate the input a lot as always.

Eric

[eabrust]

Originally Posted by Power Hungry

I looked over the graphs a bit and I'll have to compare them against the ICP tables in your files. It does seem odd that you're barely hitting 2000 PSI most of the time and it makes me wonder if the scaling in the AE software might be off. Based on the ICP Desired tables, at full throttle above 2400 RPM the ICP output should be be at LEAST 3200 PSI if not more. I get the feeling something is a bit screwy. One thing that is good is that your Desired and Actual ICP values track very closely together. This is a good indication that your HPOP may be just fine.

Morning Bill,

Wondering if you might still be able to take a peek at my tunes regarding the peak ICP I'm seeing using AE in my 80DD vs 100 Perf tunes. I wanted to try to rule out AE and scaling, as I'd hate to find I have an expensive diagnostic tool that gives 'junk' data depending on the tune....

In stock, I can get ICP up over 3500 psi, and reported IPR DC is ~77%.

In the 100 Perf tune, ICP doesn't get quite as high, but still over 3000 psi, with IPR DC ranging from 75-85% I assume that the lower pressure for the same IPR DC as stock is due to the injection pw increase and use of more oil, (but I wasn't recording PW at the time to compare that ).

In the 80DD tune, ICP always stops right at 1740 psi, no matter what, and IPR DC is only around 60% maximum. Unless the given tune could possibly affect the scaling or passing of data to AE, it seems the data indicates the truck isn't trying to make any more pressure given that IPR DC stops increasing also.

No complaints on any of the tunes, as the 80DD runs great and is the tune I run most. I just really want to understand what I'm seeing to know that AE isn't providing bogus data and everything is working (at least as the tunes are commanding).

Regards
Eric