HPOP Question

bigpanther2004

bigpanther2004

New member
Just wanna get everyone input on what hpop to go with anyone better than the other or ones to stay away from? i'm running single shot injectors 175cc i believe not sure on the nozzle size, i was just looking to upgrade on my pump, keeps throwing the code for ICP
 
Focus first on the cause.... meaning what pulsewidth is your tuning calling for?

A halfway decent HPOP should be able to keep up with 175cc single shots. But if the tuning is calling for overkill pulsewidth, then it's going to struggle to maintain pressure.
 
i believe its a 1211 and im not sure what the pulsewidth the tuning is calling for, im running ts 6 position with edge juice with attitude, One thing i have noticed is that it will only throw the code when i have the ts on high tune and edge on 5, had the scan tool hooked up driving around and maybe they are not stackable but i was watching the ICP pressure and when the edge and ts were both on the pressure wouldnt go over 2000 psi but with the edge off i could spike 3200 any idea on that?
 
bigpanther2004 said:
i believe its a 1211 and im not sure what the pulsewidth the tuning is calling for, im running ts 6 position with edge juice with attitude, One thing i have noticed is that it will only throw the code when i have the ts on high tune and edge on 5, had the scan tool hooked up driving around and maybe they are not stackable but i was watching the ICP pressure and when the edge and ts were both on the pressure wouldnt go over 2000 psi but with the edge off i could spike 3200 any idea on that?
Click to expand...

There is zero reason to stack in these trucks. You're now learning why.

What's happening is the Edge Juice is trying to fool the PCM, which then jacks with what the tuning on the chip is trying to accomplish. The Edge Juice simply makes the ICP signal appear to the PCM that oil pressure is too low, and thus the PCM increases the duty cycle of the IPR to try and raise ICP.

What most people don't realize is the tuning parameters that are common with a chip. Once you start to add pulsewidth, and in many cases of tuning - increase the fuel injection pulsewidth multiplier - that the PCM will ramp up pulsewidth when it sees lower than expected ICP on a WOT run.

In other words, you punch the accelerator. The Juice tells the PCM that oil pressure is low. The PCM responds two ways, it tries to increase duty cycle of the IPR to ramp up oil pressure, and it also increases fuel injection pulsewidth to try and squeeze out more fuel as the tuning on the chip is calling for. So when the pulsewidth goes too wide, the volume the HPOP can physically supply cannot keep up with the demand at that pulsewidth, and the pressure continues to drop. Once that pressure drop is sustained, a check engine light and a P1211 code is thrown. In the mean time, the engine feels doggy and you probably have some smoke out the tailpipe accompanied with high EGT's.

Take out the Edge Juice. You have no more use for it. You can keep the Attitude if you use it as gauges, there's no problem there. Let the tuning on the chip work as it's designed. If you aren't satisfied with the tuning on the chip, get it reburned by another professional 7.3L tuner. Nearly all of them can burn tunes to that chip, and quite a few have excellent programs for single shots.
 
Nice! simple explanation :thankyou2: Kinda old news thou but very informative for some of the newer guys. :clap:
 
I thought it was kinda weird that it only did it with the edge on, thanks any thoughts on who do to tuning through I believe I have swamps now that's what I was told it has on it?
 
im a cummins guy, a buddy of mine wants to give his 99 a kick in the pants. has a dp tuner intake exhaust gauges. could a stock hpop handle a mild set of sticks and a 38r? or would an upgrade be in need. dont mean to high jack your thread, just lots of knowledge here!
 
A stock HPOP Will work a set of single stage.injectors fine. But you might find a little loss or flat line on the high end..
 
JJeepyjohn said:
A stock HPOP Will work a set of single stage.injectors fine. But you might find a little loss or flat line on the high end..
Click to expand...

That would depend on 1) the injectors used, and 2) the tuning.

With the injectors in my sig, I can hold 3,000 psi of ICP rock solid - all on a bone stock HPOP. At the same time, I'm not fully utilizing these injectors. They are capable of way more fuel, but my rods wouldn't handle it.

I'm of the mindset that a person should shoot for a hp goal, then get injectors that are capable of more than that, then let the tuning dial into that goal.

The old school of thought is that if you want say 400 hp, you get the injectors that barely get you there, and have the tuning run them at full tilt. That's when the HPOP can no longer keep up. But if you go larger on the injectors and limit the pulsewidth, often times the HPOP can keep up easier.

Of course, that only works up to a certain point. Eventually with any injector, as you go up in power, you'll reach the limits of the HPOP. If your power goals are really high, a modified HPOP will be necessary at some point.
 
Ok. Pocket, you got me. I should have been more descriptive. And included with FullFORCE stage 1 single shots and TS tunes. LOL
 
JJeepyjohn said:
Ok. Pocket, you got me. I should have been more descriptive. And included with FullFORCE stage 1 single shots and TS tunes. LOL
Click to expand...

To be honest, the differences in your truck and mine actually highlight very well what I'm talking about regarding tuning and holding ICP with different sized injectors. I'll explain for those who aren't familiar with it. I'm sure you already know this.

Your Stealth HPOP and Stage I's... I'm guessing you're knocking on close to 400 hp, right? Probably with a stock HPOP, you might lose a few ponies, because at full PW to squeeze out all the fuel, the stock HPOP wouldn't have been able to supply the oil volume needed to keep the pressures up. I'm guessing your PW at WOT on your highest HP tune is at least 4 MS, maybe more. I'm basing this on what I typically see with tuning from other guys.

On the flip side, I can make 70+ hp more than your truck, and my PW is capped at 2.3 ms. So I'm running close to half, possibly even less than half the PW you're running.

By limiting the PW, and combined with the inherent nature of hybrids requiring less oil anyway, I can make more power but doing it with a stock HPOP rather than requiring a modified one to maintain pressures.

Of course (and I'm sure you know this, but for those who don't...) nozzle size comes into play too. Larger nozzles allow for a greater fuel flow in less time. So that's another reason why I can keep PW down.

Which is why I said earlier that my own personal feelings is that a person should have a power goal, and then choose injectors that can go beyond that power goal easily. Then dial back the PW, and it becomes easier to maintain ICP. Plus with shorter PW, EGT's are lower too. So there's several benefits to going larger and dialing back, rather than just barely getting there with injectors and additional supporting mods (like a modified HPOP for example).

This hasn't always been the train of thought for these motors. The biggest reasoning for that was tuning. Just a few years back, going from Stage I's to Stage II's was a gigantic difference in smoke and EGT's. The reason for that was because tuners were having both injectors call for the same PW, which was typically far too much for Stage II's, making it difficult to tow with them or even use as a daily driver. Once tuners started figuring out a bit more about the effects of nozzle sizes, and how limiting PW can make even large nozzle injectors run extremely tame, then that's when the game started to change.

I still remember years ago when people would ask on the forums if they should go with stage I's or stage II's, and the very first response was to ask if they planned to tow. Now when someone asks if they should go with I's or II's, no one cares if they are towing because proper tuning will take care of all that.

Hell, when I put these 250/200's on my truck, many people thought my motor wouldn't last but a few weeks. Well, it's been a year and a half, and well over 30K extremely hard miles. Still going strong. Plus I'm making more power than I ever intended (I was going to stop at 400 rwhp).

Anyway, I'll get off the soap box now. LOL
 
Again.. great explanation.
FYI, I noticed my power flat line on the strip with a stock HPOP along with the injector chip combo. After I added the stealth pump with same injector chip combo it was gone and was able to hold 30+ lbs of boost at a hard dig at 110 mph. This will further exemplify what you were saying. If I were to get custom tuning I could easily see 400 rwh. At this point I am at 378 and 780 and still get 18mpg around town.
 
Is stealth's hpop the best bang for your buck? I just have an early 99 7.3 w/ ts 6 position chip, cool air and 5" exhaust and it flat lines quick even in the milder settings. I was told to do injectors and hpop, just wanting to know what brands are good for my application.
 
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