Injector pulsewidth outcome

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
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kristoe36
Posts: 5
Joined: Mon Oct 17, 2022 2:15 pm
ECU Model: S100 Pro
Firmware Version: 90.26

Injector pulsewidth outcome

Post by kristoe36 »

Hey guys,

I wanted to ask the DTA family about what factors play into the following scenario.

The ecu: DTAFast S100 PRO
Engine: E46 M3 - S54B32 - Stock Injectors

For testing this, i have checked that all enrichments available are off and nothing related to fuel enrichment is displayed in the Real Time Mapping display. Additionally interpolation has been turned off.

I have quite a big difference in actual injector pulsewidth vs injector pulsewidth set in the main fuel table.

For example: the injector pulsewidth set for idle at 0% throttle and 1250 rpm has been set to 1.97ms
The actual pulsewidth shows 2.52ms

What causes this difference in outcome? The difference is present in the whole range of operation, so not only idle. I would like to be as close as possible when in ideal conditions (batt volt as expected 13.8v, injector deadtimes set correctly etc...)

Attaching a picture from the log at idle. Also the fuel map.

Thanks in advance
Attachments
Fuel map
Fuel map
Log at idle
Log at idle
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Injector pulsewidth outcome

Post by stevieturbo »

Unless you are doing steady state cell tuning with where you can fix load/rpm in the relevant cell, there is no reason to turn interpolation off.

IJPW will be whatever is in the table, plus injector dead time and any other compensations that may be applied.
kristoe36
Posts: 5
Joined: Mon Oct 17, 2022 2:15 pm
ECU Model: S100 Pro
Firmware Version: 90.26

Re: Injector pulsewidth outcome

Post by kristoe36 »

Hi stevieturbo,

Interpolation Off was just there to make sure that the injector pulsewidth isnt being affected by neighbouring cells when showing you this result.
kristoe36
Posts: 5
Joined: Mon Oct 17, 2022 2:15 pm
ECU Model: S100 Pro
Firmware Version: 90.26

Re: Injector pulsewidth outcome

Post by kristoe36 »

Also helpful if anyone had the fuel calculation model the S100Pro uses.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Injector pulsewidth outcome

Post by stevieturbo »

What fuel calculation model ? I already explained
kristoe36
Posts: 5
Joined: Mon Oct 17, 2022 2:15 pm
ECU Model: S100 Pro
Firmware Version: 90.26

Re: Injector pulsewidth outcome

Post by kristoe36 »

Hi stevie,

Misread your answer at first, missed the fact that inj deadtime is ofcourse just added to the PW specified in the fuel map.

Thanks, that answers my question.

We can close this thread.
kristoe36
Posts: 5
Joined: Mon Oct 17, 2022 2:15 pm
ECU Model: S100 Pro
Firmware Version: 90.26

Re: Injector pulsewidth outcome

Post by kristoe36 »

kristoe36 wrote: Mon Oct 17, 2022 5:16 pm Hi stevie,

Misread your answer at first, missed the fact that inj deadtime is ofcourse just added to the PW specified in the fuel map.

Thanks, that answers my question.

We can close this thread.
I found it a bit annoying at first because when checking logs for our cars after competitions and trying to sort out anomalies and really fine tune some sectors of the fuel map, the numbers didnt easily match up, and now I know its due to deadtime. Would be great if it was possible to log or display the injector pulsewidth w/o deadtime to get a true value of fuel map + any resulting enrichment more easily. Battery comp is something static so that once you set and validate it, you dont think about it anymore for the given set of injectors.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Injector pulsewidth outcome

Post by stevieturbo »

Battery comp is not static, unless battery voltage is entirely static. ( or you've filled in corrections that are static despite changing voltage/pressure )
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