XDI High Pressure Fuel Pump upgrade

ninjacoupe

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I did not do the camshaft or the injector upgrade. As of now, I am not limited By the GDI system.
Awesome!! I was thinking there had to be a benefit to just the pump upgrade which is a lot more feasible for most people. Looking forward to seeing more of your updates to this!

 
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engineermike

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Awesome!! I was thinking there had to be a benefit to just the pump upgrade which is a lot more feasible for most people. Looking forward to seeing more of your updates to this!
Once you start digging into the system you start to understand what the limiting factors are and when they kick in. For instance, the pcm controls the rail pressure via a commanded duty cycle of the pump. If you are below 100% DC, you are still successfully controlling the pressure. Once you reach 100%, you are out and need more pump capacity. That’s where the cam comes into play. Next, you have to look at the injector opening (SOI) and closing (EOI) to make sure you have enough time to get the desired fuel in there. Basically, it usually starts injecting fuel about 30 deg ATDC on the intake stroke and leaves the injector open until the desired amount of fuel is injected. When the demand is high it will continue to inject fuel part-way up the compression stroke. There is a maximum total crank angle opening but also a latest possible closing (EOI limit). If you exceed either of these maximums, the pcm will either supplement with port or close the throttle, depending on the cal. However, I’ve logged these values and mine barely stays open past BDC at heavy load, so I don’t think I’m near the injector limit at this time.
 

markmurfie

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Big DI injectors and Pumps = Big power gains.

End
of
Discussion

They just hurt the wallet. (Ive made 1,216 rwhp on DI only... its awesome)
This is a discussion about increased donation resistance and increased timing advance. Nothing about power gains will be shown. I'm not saying there isn't potential power gains. I'm just saying we might see another hurt engine and a 18+ lower compression build sooner rather than later, if timing is continuously pushed to the borderline of detonation. He knows he can add boost, but isn't paying attention to what he needs to be, to determine when to add timing and when to add boost.
 
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engineermike

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@markmurfie thank you for your concern. I know better than to say that my motor will not fail but I can say with a high degree of certainty that my calibration strategy is currently undoubtedly safer than at least two of the most common calibrations used in these cars. How do you know what I am paying attention to anyway?
 

markmurfie

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@markmurfie thank you for your concern. I know better than to say that my motor will not fail but I can say with a high degree of certainty that my calibration strategy is currently undoubtedly safer than at least two of the most common calibrations used in these cars. How do you know what I am paying attention to anyway?
What you were/are doing with timing doesn't sound safe at all. Knock had to happen to see what you are seeing.

Who knows what you are looking at as far as saftey is concerned, you certainly are looking at the knock sensor with a limited idea of how to use it safely. Not even letting the ECU slowly creep into detonation to minimize it's intensity.

It's also why I asked how you were measuring torque/power output. Timing doesn't always mean more power. I don't need to actually see the numbers just a measuring process. With out even a vague hint as to what you are looking at, I assume it's nothing and you are tuning it strictly by the knock sensor indicating knock.

Just a voice of caution about what you are doing.
 


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engineermike

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What you were/are doing with timing doesn't sound safe at all. Knock had to happen to see what you are seeing.
Mine knocked much more often when I was using a very common calibration than it does now. Another example is the Roush cal....it runs them right into knock, then backs off, then into knock again. OAR is off so it can't even learn from it.

Who knows what you are looking at as far as saftey is concerned.......With out even a vague hint as to what you are looking at....
You claimed to know what I was looking at in post #18. I was just curious how you knew.

Not even letting the ECU slowly creep into detonation to minimize it's intensity.
How quickly am I adding timing vs the ECU's knock advance?

Timing doesn't always mean more power.
It does when you are below MBT and knock.

Just a voice of caution about what you are doing.
Thank you for your concern.
 
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ProChargerTECH

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This is a discussion about increased donation resistance and increased timing advance. Nothing about power gains will be shown. I'm not saying there isn't potential power gains. I'm just saying we might see another hurt engine and a 18+ lower compression build sooner rather than later, if timing is continuously pushed to the borderline of detonation. He knows he can add boost, but isn't paying attention to what he needs to be, to determine when to add timing and when to add boost.

Huh?

Running DI only (no port blending) will totally allow him to run more timing and make more power. I have had great joy in being able to run larger DI injectors and large DI pumps, to remove the port injectors entirely on 1000+ hp cars.

The last one that made the 1,216 rwhp HP.... gained 166 hp just by removing the port injectors.

Virutally "free" horsepower in the means that the boost stayed the same, the fuel stayed the same, and the only change was being able to property run DI only.

Whats crazy is I think the car will actually pick up 200hp, though it ran out of intank pump (feeding the DI pump) so the run had to be cut short for safety reasons.
 
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engineermike

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Just an update to anyone interested, I've been tuning the car with the new XDI pump as spare time permits. To re-cap, previously I was getting a repeatable 1.2-1.4 deg of knock retard at a specific engine speed and load. So far, I've been able to add 2 deg of spark timing at that point and I'm seeing zero knock retard. The net change at that operating point is an added 3-4 deg of spark timing so far, which exceeded my expectations.

The duty cycle of the XDI pump has rarely gone past 80% so far. I've been keeping an eye on my injection window to ensure I don't run out of time for injection, as that would indicate my injectors are undersized. I was surprised to see when COT mode switched on, the injection angle increased by a whopping 70 deg, pushing way back into the compression stroke, which is even better for knock suppression (the above timing figures were NOT in COT mode). However, even in COT, there is still plenty of window available for injection. I've since increased the GDI pressure by 100 psi per XDI's recommendation, which will also buy a few degrees. WOT GDI injection generally starts around 30 deg ATDC on the intake stroke and lasts until about BDC +/- before compression. In COT mode, I've logged injection lasting as late as 110 deg BTDC.
 

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Good information. Hopefully this will catch on more.
 

4sdvenom

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Very good info! Thank you for the update, and definitely looking forward to more! Quick question since I'm still getting educated on the GDI. What are you referring to when you say tuning in COT mode? I'm sure it's obvious but I couldn't figure it out tonight to save my life!
Thanks
Ken
 
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engineermike

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..Quick question since I'm still getting educated on the GDI. What are you referring to when you say tuning in COT mode? ...
Cat Over Temp mode, where it enrichens the a/f ratio when the calculated catalyst temperature exceeds a threshold. The fuel demand makes a step change increase when this happens. You should have enough fuel system overhead to cover this scenario plus temps colder than those experienced during tuning.
 

4sdvenom

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Cat Over Temp mode, where it enrichens the a/f ratio when the calculated catalyst temperature exceeds a threshold. The fuel demand makes a step change increase when this happens. You should have enough fuel system overhead to cover this scenario plus temps colder than those experienced during tuning.
Thank you!
That is the only thing I was not following!! The rest I could. Makes a difference lol
 

sigintel

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Thanks for posting up and moving the ball forward together. DI is expensive but effective tech in getting around fuel limitations in port injection only combustion regimes.
I think a whole world would open up to more tuners to get more fuel and combustion analysis tools and hardware available. Maybe EGT probes? Anything that helps characterize what is happening immediately before detonation and generally aid exploration of combustion.
Combustion pressure sensors on plugs are the shiznit but omg $$$.
Getting into cat temp issues could be exciting and terrifying all at once, math physics chemistry = more horsepower!

Ford should consider just loan out freely/on deposit such tools to anyone thats clearly ready.
 
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engineermike

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I decided to share some more data from my tuning since the last update on 1/4.

I was using 5000 rpm as my test point to reduce the number of variables. This is the last log I took before installing the XDI HPFP, where you can see I was commanding 15.9 deg Borderline timing (BKT) and it knocked (red line). Load was 1.46 and charge temp 92 deg. This behavior was repeatable.

1618333993781.png


As of my January 4th update, the following log is where I was commanding 18.1 deg Borderline timing and there was no knock response. Load was 1.49 and charge temp was 80. You might argue that the charge temp helped with the knock response, but the load would have counteracted some of that. I commanded 2.2 deg more spark and didn't get the 1.4 deg knock retard, so the net gain was 3.6 deg in this case.

1618334309094.png


I continued to push and tweak some other things in the calibration. My disclaimer is that some of the further improvements could be due to other things in the calibration rather than just the increased GDI blend that the new pump enabled, but either way I'm pretty excited about the results. In the following, I was commanding 19.2 deg Borderline timing and there was no knock retard. Load was 1.46 and charge temp 89, similar to the initial log above.

1618334833407.png


All of the above data was sampled at 5000 rpm. What's even more impressive to me was that at 7250 rpm, 1.57 load, and 83 deg charge temp, I was commanding 20.1 deg spark and still no knock retard:

1618335150886.png


Another point worth noting is that on January 4th, I posted that the end-of-injection was occurring at 110 deg BTDC (during compression). I've since logged end-of-injection as late as 75 deg BTDC. From a knock-suppression perspective, injection during compression is more beneficial than injection during intake.

All of the above was on Shell 93 octane with no octane booster whatsoever.
 

 
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