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ECUFlash accel enrichment table not really accel enrichment?

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Old Apr 29, 2008 | 10:05 PM
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ECUFlash accel enrichment table not really accel enrichment?

I've been going through some of the fuel subroutines. It looks to me that the "accel enrichment" table in ECUFlash is not really an acceleration enrichment. Based on what I've deciphered, it appears to be a rpm-dependent scaling factor for a barometric pressure based compensation to the IPW. I read somewhere that people already knew that the accel enrichment table wasn't really accel enrichment, but I haven't been able to find any threads or posts on the topic. Can anyone point me in the right direction?
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Old Apr 29, 2008 | 10:11 PM
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i was told by the other ecuflash gurus that it worked like an accelerator pump did on the carbs of old. when you tipped in on the throttle it richened it up a little to make power onset smoother
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Old Apr 29, 2008 | 10:20 PM
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What you describe is the intent of an acceleration enrichment routine, but I don't think this is what the table in ECUFlash represents.

Its definitely a barometric pressure based compensation. The general effect of the compensation is to increase the IPW as the barometric pressure increases. Acceleration will lower the air pressure at the MAF, so this would cause a lean out effect which is the opposite of what would be expected if it were an enrichment routine.

I just figured out too that the "acceleration enrichment" item in EvoScan is nothing but another load value in the ECU, so its wrong as well!
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Old Apr 29, 2008 | 10:32 PM
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very interesting hope some of the other great minds will chime in
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Old Apr 30, 2008 | 02:31 AM
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Quote my own Post
Not accel enrichment but a similar issue.
By the way, I don't know if somebody has already told this.
During dissassemble I find out that the table named "Boost Enhancement Enrich/Enlean (Anti-lag) Map" is used only in the ignition function.

It changes the ignition value from the high/low ignition map under some circumstances. (If a flag is set: I don't know when this flag will be set)
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Old Apr 30, 2008 | 03:19 AM
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Part of an email I got from Bez concerning accell enrichement. He knew the table that was previously defined did nothing like it was described:


Originally Posted by Bez Bashni
But at the beginning stage U could use the patch I send before - but you need the accell enrichment to correct. I found the real acell enrichment tables and how it works in evo-I will use stock acell enrichment in my patch-so U can tune these tables right now.

add this to your xml-I spend ~1.5 hours finding the exact adresses 4 your definition..

<table name="Asynch_Acell_Enrichment" category="Fuel" address="1254" type="2D" level="1" scaling="uint16">
<table name="X" type="Static Y Axis" elements="5">
<data>pause_period</data>
<data>min_TPSdelta</data>
<data>Max_pulsewidth</data>
<data>idle_TPSRange</data>
<data>after_engine_start_addition</data>
</table>
</table>

<table name="Asynch_VS_TPSDELTA" category="Fuel" address="32b6" type="2D" level="1" scaling="uint8">
<table name="X" type="Static Y Axis" elements="9">
<data>0</data>
<data>1</data>
<data>2</data>
<data>3</data>
<data>4</data>
<data>5</data>
<data>6</data>
<data>7</data>
<data>8</data>
</table>
</table>

<table name="Asynch_TPS(Rpm) Limit" category="Fuel" address="32c6" type="2D" level="1" scaling="WGDuty">
<table name="X" address="6c26" type="Y Axis" elements="10" scaling="RPM"/>
</table>

<table name="Asynch_Accel_vsRPM" category="Fuel" address="32e4" type="2D" level="1" scaling="uint8">
<table name="X" address="6c26" type="Y Axis" elements="10" scaling="RPM"/>
</table>


Heres mine examle of altering enrichment - left WAS -right - NOW (see .jpg)


Briefly
1 table
Pause period - TPS dynamics measurement cycle (shorter -faster) It measures TPS and copares it to OLD TPS value
min TPSDLTA - the minimum encrease of ADC value to recognise enrichment (TPS-OLDTPS) shoud be > TPSDELTA
Max Pulsewidth - total maxium enrichment pulsewidth
Idle tpsrange - the range withn wich the enrichment will work.
after engine start addition - the asynch PW constantly used within first ~5 seconds of engine started.

Asynch vs TPS - the amount of enrichment added for each point of tps difference.
Asynch_TPS(Rpm) Limit The TPS(RPM) above wich the enrichment will not be added
Asynch_Accel_vsRPM the general enrichment -Limits max total enrichment vs RPM - in newer ecu its an addition to some value)

these params exists on evo all ecus..The adressses could vary.
To log FPULSE2 (asynch injpulse) RAM:FFFF6D08 FPULSE2 i give U the ref 2 its adress 4 your ecu

Last edited by Tuner@Swift; Apr 30, 2008 at 03:22 AM.
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Old Apr 30, 2008 | 06:13 AM
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Originally Posted by mrfred
What you describe is the intent of an acceleration enrichment routine, but I don't think this is what the table in ECUFlash represents.

Its definitely a barometric pressure based compensation. The general effect of the compensation is to increase the IPW as the barometric pressure increases. Acceleration will lower the air pressure at the MAF, so this would cause a lean out effect which is the opposite of what would be expected if it were an enrichment routine.

I just figured out too that the "acceleration enrichment" item in EvoScan is nothing but another load value in the ECU, so its wrong as well!
Great work, mrfred.

So, this is sort of a lookup table again, in a similar way that the air density had a lookup table when we were talking about what I thought was the mass airflow routine?

As baro goes up, the mass airflow goes up, so accordingly the mass fuel (IPW) has to go up as well. It sound like instead of doing exact calculations, this table is used sort of as a lookup for part of the calculations similar to the air density lookup table?

Am I understanding this correctly?


Thanks,
Eric
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Old Apr 30, 2008 | 06:56 AM
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lol, time to detune my accel enrich tables and see what happens. I've been looking for something that compensates for baro changes.
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Old Apr 30, 2008 | 11:20 AM
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Originally Posted by honki24
lol, time to detune my accel enrich tables and see what happens. I've been looking for something that compensates for baro changes.
Have you looked at the "Baro and Air Temp Compensation" 3D table?
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Old Apr 30, 2008 | 11:52 AM
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In an ongoing attempt to better my cruising AFR's/performance, I lowered the numbers in this table around the cruising areas. I did notice that the initial tip in was leaner and stayed more toward 14.7ish then stock settings in this table. With the stock settings I was dropping to 10's AFR upon small throttle changes. Not sure if that helps the discussion any?

SQ
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Old May 1, 2008 | 07:38 AM
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Originally Posted by razorlab
Have you looked at the "Baro and Air Temp Compensation" 3D table?
Only briefly, but I'm not exactly sure how to use them. I could trial-and-error it probably, but w/ everything on my plate right now that's usually not feasible. You know... a good "how to" thread would be one that explains in detail each table in ECUFlash that is currently defined and how it works. It could be added to as new definitions arise. That would be an amazing resource. lol, so many ideas... so little time.
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Old May 1, 2008 | 07:52 AM
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BTW, how do I simply rename this table to something like "NOT accel enrichment"? I tried just right clicking it, going to the evo7base tab and changing its name. I also tried going into the evo7base xml and changing it.. but both result in ECUFlash thinking the table is undefined. There's obviously somewhere in the code that is specifically looking for the name "accel enrichment" and I'm screwing that up by simply renaming it.
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Old May 1, 2008 | 07:53 AM
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You have to change the name in both evo7base.xml and your ROM's XML file.
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Old May 1, 2008 | 08:43 AM
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all i know is it does function how it says, i put really higher #'s in the map and it definetely loss power from to much fuel. But like you said maybe it also is barometric compensation also who knows.
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Old Jul 30, 2008 | 08:17 PM
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Any developments on this?

I finally had time to turn off lean spool on my personal Evo (I know, I know ), the AFR is constant in each gear now but I still get a big ol AFR enrichment right at peak load when banging through the gears. It's almost a full AFR point dip.

I tried bringing down the accel enrichment numbers but it didn't do much.

here is an example logged, I have BARO on there as well in plotted in pink:

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