load = map vs load = tps

[evo_gerard]

good day everyone, 

i'm looking for some advice on when to choose load = tps vs load = map. i've read in the help file that it could be used on a single throttle car with unstable vacuum. I'm doing a project here with a car that has very large and aggressive cams. its idle is around 1050rpm and it vaccum is around -29kpa (MGP). Around there the VE value is around 50. once i go for a drive and the car goes extremely lean the 0kpa (MGP) area. to try to remedy this i start adding VE in the cruise areas. but i end up reaching the maximum value of 150. i know this can't right because we haven't really gone into boost yet. probably just 5 psi at most.

I'm probably going to do some mechanical checks on the fuel system to make sure all is good. 

what i'm asking is would i benefit from going load = tps and using a 4d fuel map for boost?

attached is a cal file and a log. the cal file is very rough as this is only my 2nd link ecu tune and the car is a bit extreme.

the log file is a little drive around with 150 in the fuel map. 

 

Edited December 18, 2020 by evo_gerard

[Adamw]

No, changing load source to BAP/MAP X-over or MAP with TP on the fuel table axis look up will not solve your problem - your VE will still be the same when manifold pressure is 100KPa.

Most of your fuel settings look right, so large VE numbers usually means the engine is not getting as much fuel delivered as the ECU thinks it is delivering.  Fuel pressure looks ok so I would be suspicious of injector flow.  Those 2000cc CNG injectors are very prone to partially seizing and or blocking so I would start with a flow test on those first.  

[evo_gerard]

good day, finally got a chance to go back to the car.

@Adamw i took you advice and we re-did all the fuel lines changed the fuel filter and cleaned and flow tested the injectors (the injectors weren't flowing evenly).

today i updated the ecu firmware. dropped the fuel pressure to match what i set in the ecu at 3 bar and went for a drive. it was better but still leaner than the target afr once the car went over into positive pressure (even thou the VE numbers are maxed at 150). i tried something to see if i could get the actual lambda to match the target. i turned on the 4d fuel table, set it to always on and i added another 20% everywhere from 20kpa MGP. it worked(see Saturday drive 2 log) . but i am very new to tuning standalone ecus so i'm coming here to ask if that is a strategy that i could employ or is it a bandage/short cut that i should not use?

i also attached the tune.

also the car is a drag car masquerading as a street car. everything is big. it previously made 1000whp with its last setup. could this car have such high VE?

i tried to attach a log before i turned on the 4d fuel table but the file was to big. also any discrepancies seen with the egt was to the egt wires not being fastened properly to the module.

any advice guys would be greatly appreciated. 

evo 7.zip

[Adamw]

No, if you have a VE of 150% something is still off.  The fuel pressure sensor calibration looks pretty odd.  What sensor do you have?

Since you have not far off realistic VE at idle, but very high under boost, it suggests maybe a fuel pressure issue.

[evo_gerard]

4 hours ago, Adamw said:

No, if you have a VE of 150% something is still off.  The fuel pressure sensor calibration looks pretty odd.  What sensor do you have?

Since you have not far off realistic VE at idle, but very high under boost, it suggests maybe a fuel pressure issue.

its using an aem 150psig pressure sensor

this is the scaling i used: https://www.aemelectronics.com/sites/default/files/aem_datasheet/30-2130-150 Sensor Data.pdf

[koracing]

It's odd they list the PSI in gauge pressure but the kpa in absolute pressure - this is a gauge pressure sensor after all.  I use the same sensor frequently.  I would recommend changing your calibration to gauge pressure since that is what the fuel pressure sensor input needs to see the proper pressure in the fuel model.  Subtract 100 from your sensor settings in Cal4.

[evo_gerard]

6 hours ago, koracing said:

It's odd they list the PSI in gauge pressure but the kpa in absolute pressure - this is a gauge pressure sensor after all.  I use the same sensor frequently.  I would recommend changing your calibration to gauge pressure since that is what the fuel pressure sensor input needs to see the proper pressure in the fuel model.  Subtract 100 from your sensor settings in Cal4.

ok will do. but this is confusing a bit now. the oil and fuel pressure sensors are aem 150psig sensors, the water pressure is an aem 100psig sensor and the MAP sensor is an aem 5bar sensor. so i'm wondering if my other sensor calibrations are wrong also?

[Adamw]

Your MAP cal looks ok.  Your water press is wrong, change to this:

Note for the fuel & oil press, instead of using cal 4 you can just set it to the preconfigured calibration "1000Kpa (150psi) TI sensor".

[evo_gerard]

9 minutes ago, Adamw said:

Your MAP cal looks ok.  Your water press is wrong, change to this:

Note for the fuel & oil press, instead of using cal 4 you can just set it to the preconfigured calibration "1000Kpa (150psi) TI sensor".

thank you very much @Adamw for the support and lightening fast replies. i greatly appreciate it.

[koracing]

On 12/13/2020 at 4:59 PM, Adamw said:

Your MAP cal looks ok.  Your water press is wrong, change to this:

Note for the fuel & oil press, instead of using cal 4 you can just set it to the preconfigured calibration "1000Kpa (150psi) TI sensor".

I've found that canned cal is pretty close just slighlty off from what the AEM sensor cal and my own various other dyno instruments read.  Even with the right cal it's always a good idea to check for offset/drift in the signal of any sensor.

I went and reviewd AEM's PSIg SS sensor data and all but the 2000psi sensor seem to show the kpa values starting at 100 instead of 0kpa.  A gauge sensor should be relative to BAP so they should all start at zero.  

[evo_gerard]

good night everyone,

i have an update. so i rescaled the pressure sensors, set over the base fuel pressure to 300kpa and even thou i'm using the fp sensor option in the "fuel system type" setting i switched to MAP referenced and set the base pressure to 300kpa and then returned the setting to fp sensor.

i went out for a drive and i saw improvement. i was able to turn off the 4D fuel map because it was alot richer than target. 

the thing is i still had 150 in the main fuel map. and it was close to being on target.  probably a few areas where it was still a little leaner than is should but also had an area as you could see in the attached log.

not to be honest the car needs some work on the ignition map so the timing numbers are way to low and this car is seeing alot of boost at wastegate pressure. i did notice that on the tail end of the little full throttle pull in the log it went richer than target which i'm guessing is a good thing.

could it be that the injector values for the primary injectors are wrong? its ID2000cc. the secondary injectors are fic 2150cc.

i got the injector deadtimes and short pulsewidth adder from ID but i'm wondering if its not flowing as much as advertised

aggressive streetdrive 2.llg KGB 7.pclr

[Adamw]

Yeah Im a bit suspicious one of the injector flow rates arent correct.  It looks like you have plenty of headroom in terms of duty cycle at the boost you where running in that log, so as a test you could try a run with zeros right across your staging table so it is running on only primary, see if AFR still tracks close to target.  Then do another run with 100% right across the staging table so its only running on the secondary injectors, and see what AFR does.  That may give us some clues where the discrepancy is.

[evo_gerard]

14 hours ago, Adamw said:

Yeah Im a bit suspicious one of the injector flow rates arent correct.  It looks like you have plenty of headroom in terms of duty cycle at the boost you where running in that log, so as a test you could try a run with zeros right across your staging table so it is running on only primary, see if AFR still tracks close to target.  Then do another run with 100% right across the staging table so its only running on the secondary injectors, and see what AFR does.  That may give us some clues where the discrepancy is.

will do just letting the holiday period pass and i'll report back as soon as possible. thanks for all your patience and assistance. it's fully appreciated.