GT350 Not entering power enrichment

[bbrooks98]

Trying to get started on tuning a gt350 on the dyno and i can't seem to get into power enrichment. Log and cal attached. Set the pedal vs throttle to zero and it still shows Fuel Source "Stoich"

[small tuner]

mod list

[bbrooks98]

Hell Horse twin turbo kit, Bosch motorsports 1000cc injectors, Fore twin fuel pump return system set to 55psi base.

[small tuner]

rise max torque ( CLIP Torque Max Indicated)

[bbrooks98]

rise max torque ( CLIP Torque Max Indicated)

Better but i think it was the max engine tq set to 7000, set it to 850 and it seems to work. Hitting insufficient fuel flow now above 6500 with the patch installed.

[small tuner]

how much boost and how much HP. can you log injectors duty cycle. fuel pressure vacuum line off?

[bbrooks98]

only 8psi dropping to 6, made 677 on a Mustang dyno. Bosch 1000cc 66% duty. Fuel pressure 55psi baro

[small tuner]

setting desired fuel pressure over Injector at 40 psi. fuel pressure should match yours tables.

[bbrooks98]

setting desired fuel pressure over Injector at 40 psi. fuel pressure should match yours tables.

I set the injector data flow rate and offset time at a 55psi constant per the bosch data I received. The fuel pump desired delta I set to 40.3 by taking local barometric pressure subtracted from the 55psi base pressure setting with no vac line attached. Then I set the adder to 55psi per this thread.

https://forum.hptuners.com/showthrea...949#post605949

Bosch 1000.jpg

[small tuner]

i will suggest to return adder to stock value and set others @55 as per fuel pressure and give it a pull

[bbrooks98]

i will suggest to return adder to stock value and set others @55 as per fuel pressure and give it a pull

I will give that a shot as the fuel pump settings have been the variable i'm not used to here.

[JFiorito]

Maybe it's your Fuel Enrichment Pedal? I've been tinkering with this lately because I'd be stuck in stoich longer than I wanted when rolling into the throttle causing some knock.

Fuel Enrichment Pedal.PNG

[bbrooks98]

Maybe it's your Fuel Enrichment Pedal? I've been tinkering with this lately because I'd be stuck in stoich longer than I wanted when rolling into the throttle causing some knock.

Fuel Enrichment Pedal.PNG

that was set to zero above 5k to always be in PE. It turns out if you max out the torque maximum for setting 1 and 2 it won't go into PE. If you set it to something more realistic it works.

Maximum tq.jpg

[veeefour]

It has nothing to do with your injector or pump - at 65% of dute we can see you have plenty of fuel. It's in your torque model and speed density.

Your LOAD wants to breach 2 at 5800 rpm which suggest 14psi of boost even tho you are targeting 6-8. ECU is trying to save you from running out of fuel.
Your MAF tells me air is there to support 800hp but your injector pulse tells me your ECM is cutting the engine torque.

[murfie]

Absolute pressure is what you would see on a fuel pressure gauge
Delta pressure is Absolute minus MAP pressure as thats the pressure on the top and bottom of the injector. This is what determines flow rate through the injector. Most injectors are calibrated at 14.7PSI air pressure at their opening. It would be unreasonable to have them spray into a complete vacuum and publish that data.

That being said if you use a injector flow rate thats 10% higher than actual, to keep AFR on target, airflow will have to be ~10% higher. They scale together. This will put MAP, load, and torque higher than where it should be. Higher airflow will make fuel flow higher as thats how FPCM determines fuel flow to control pump.

Fuel flow based on a FPCM thinking its controlling a returnless system isn't accurate on a return style fuel system. You can raise the axis values of fuel flow and fuel mass, in the fuel section to make fuel source stay CL stoich, but really with a return style system you are not monitoring fuel flow at all, its flowing at maximum all the time excess is returning to the tank. All the inferred data about pressure becomes obsolete with a 1:1, and the only thing that matters is the single injector flow rate its keeping it at. You do want to monitor that the regulator is able to maintain rail pressure under high loads, as is now how you tell if you have sufficient flow from the pump.

[bbrooks98]

It has nothing to do with your injector or pump - at 65% of dute we can see you have plenty of fuel. It's in your torque model and speed density.

Your LOAD wants to breach 2 at 5800 rpm which suggest 14psi of boost even tho you are targeting 6-8. ECU is trying to save you from running out of fuel.
Your MAF tells me air is there to support 800hp but your injector pulse tells me your ECM is cutting the engine torque.

This is probably spot on. The question is would that trigger the insufficient fuel flow? I've seen plenty of s550s and s197s with inflated load values that run fine without that popping up. Also aside from it displaying that limit, it seems to not effect fueling in anyway.

Airflow is probably high because at 8psi the motor was too knock prone for pump gas.( it actually ran 10 when timing was lowered enough for pump). So because of the knock we put some ethanol in it to add some knock resistance since changing WG springs was too much a task at that moment. At the time we were on the dyno and did not have a content gauge, I had to take a guess on content based off trims. The stoich value is currently set in the 10s.

Once I return i will take an actual ethanol content reading and scale the maf to match the correct stoich content. It was also a mustang dyno I've never used so typically 677 is more on a dynojet from what the owner kept telling me and i wasn't sure how much more based off airflow i should see. This wasn't my usual dyno I use.

[bbrooks98]

Absolute pressure is what you would see on a fuel pressure gauge
Delta pressure is Absolute minus MAP pressure as thats the pressure on the top and bottom of the injector. This is what determines flow rate through the injector. Most injectors are calibrated at 14.7PSI air pressure at their opening. It would be unreasonable to have them spray into a complete vacuum and publish that data.

That being said if you use a injector flow rate thats 10% higher than actual, to keep AFR on target, airflow will have to be ~10% higher. They scale together. This will put MAP, load, and torque higher than where it should be. Higher airflow will make fuel flow higher as thats how FPCM determines fuel flow to control pump.

Fuel flow based on a FPCM thinking its controlling a returnless system isn't accurate on a return style fuel system. You can raise the axis values of fuel flow and fuel mass, in the fuel section to make fuel source stay CL stoich, but really with a return style system you are not monitoring fuel flow at all, its flowing at maximum all the time excess is returning to the tank. All the inferred data about pressure becomes obsolete with a 1:1, and the only thing that matters is the single injector flow rate its keeping it at. You do want to monitor that the regulator is able to maintain rail pressure under high loads, as is now how you tell if you have sufficient flow from the pump.

So going off that, I should probably set the delta to the 14.7 standard rather than the local baro. Other than that i think the rest was scaled correctly if the injector data provided was accurate.

[murfie]

The delta your 1:1 is maintaining is what determines the fuel flow value. So going off the local barometer is correct. Just using the 55PSI flow rate they give you may not be.

If they determined 55PSI is a certain flow rate, with air pressure around 14.7 or not very far above sea level, this number is just a guess. Then some one at a high altitude like 6000Ft, would actually have a higher fuel flow at the same 55psi rail pressure, because the air pressure would be lower. So instead of a 40.3 delta pressure, they might have a 43.3 delta pressure. The person at high altitude, would probably want to use the 58PSI flow rates for accuracy. This probably doesn't induce much error, and even less when you are talking about 14.7 compared to 14.5 or 14.9. It's all just a pursuit of reducing as much error out of the injector control as possible to get the most accurate air mass values the rest of the tune is going to use. If you have a known good MAF like OEM or from PMAS, you can actually use that to set your fuel pressure to match the flow rate you are using.