What is the load algorithm?
Jun 28, 2006, 01:36 AM
#5
This information below may be useful on how the ecu calculates load. Notice I said maybe, I just found this while searching around.
http://www.gems.co.uk/downloads/Manu...0draft%20R.pdf
http://www.gems.co.uk/downloads/Manu...0draft%20R.pdf
Jun 30, 2006, 04:55 PM
#6
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Just found this posted by Al. Food for thought. Hmm...
"The estimated load value is variable and is effected by the relationship between power produced and maf signal. Alterning the VE of the engine will effect the calculation the ecu uses to estiamte boost level."
"The estimated load value is variable and is effected by the relationship between power produced and maf signal. Alterning the VE of the engine will effect the calculation the ecu uses to estiamte boost level."
Jul 1, 2006, 10:12 AM
#7
There are several tables that we still dont have. The primary VE table is one of them, and its probably one of the most important ones to get. Once we have access to the primary VE table we will be able to easily scale everything for new cams, stroker kits, or whatever.
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Jul 1, 2006, 10:49 AM
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VE tables are usually associated with speed density based ECU's. A speed density based ECU will look at the MAP(pressre) sensor (load) and the RPM of the engine and look those up in a VE fuel table. These type of ECU's dont' know that more air is coming into the engine because of a bigger exhaust, hotter cams, ect.
Mass airflow based ECU's use input from the MAF sensor (Mass of air or Volume of air depending on sensor), air temp sensor, ect to calculate how much fuel the engine needs. This way the fueling should be compensated for cams, bigger exhaust, ect.
Not to argue but if the EVO is Karman vortex (volume measurement) and it reflects in the load calculations when we do modifications that increase volumetric efficiency. I guess I don't understand why there would also be a need for a VE table, we already have a load calculation algorithm and a fuel table based on load and rpm.
Mass airflow based ECU's use input from the MAF sensor (Mass of air or Volume of air depending on sensor), air temp sensor, ect to calculate how much fuel the engine needs. This way the fueling should be compensated for cams, bigger exhaust, ect.
Not to argue but if the EVO is Karman vortex (volume measurement) and it reflects in the load calculations when we do modifications that increase volumetric efficiency. I guess I don't understand why there would also be a need for a VE table, we already have a load calculation algorithm and a fuel table based on load and rpm.
Jul 1, 2006, 01:02 PM
#9
Its actually what the MAF scaling and MAF smoothing table is for.. Those adjustments are for abhorrant MAF readings, or if the airflow reading is out of sync with the actual demand of the engine.. People rarely adjust those because its not really necessary to change it.
Last edited by MalibuJack; Jul 1, 2006 at 01:05 PM.
Jul 1, 2006, 01:53 PM
#10
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Originally Posted by MalibuJack
Its actually what the MAF scaling and MAF smoothing table is for.. Those adjustments are for abhorrant MAF readings, or if the airflow reading is out of sync with the actual demand of the engine.. People rarely adjust those because its not really necessary to change it.
Jul 1, 2006, 02:31 PM
#11
Originally Posted by AlwaysinBoost
not to get too far off topic but I though those two tables were used to adjust for the addition of an intake?
Jul 1, 2006, 04:04 PM
#12
Originally Posted by AMS
VE tables are usually associated with speed density based ECU's. A speed density based ECU will look at the MAP(pressre) sensor (load) and the RPM of the engine and look those up in a VE fuel table. These type of ECU's dont' know that more air is coming into the engine because of a bigger exhaust, hotter cams, ect.
Mass airflow based ECU's use input from the MAF sensor (Mass of air or Volume of air depending on sensor), air temp sensor, ect to calculate how much fuel the engine needs. This way the fueling should be compensated for cams, bigger exhaust, ect.
Not to argue but if the EVO is Karman vortex (volume measurement) and it reflects in the load calculations when we do modifications that increase volumetric efficiency. I guess I don't understand why there would also be a need for a VE table, we already have a load calculation algorithm and a fuel table based on load and rpm.
Mass airflow based ECU's use input from the MAF sensor (Mass of air or Volume of air depending on sensor), air temp sensor, ect to calculate how much fuel the engine needs. This way the fueling should be compensated for cams, bigger exhaust, ect.
Not to argue but if the EVO is Karman vortex (volume measurement) and it reflects in the load calculations when we do modifications that increase volumetric efficiency. I guess I don't understand why there would also be a need for a VE table, we already have a load calculation algorithm and a fuel table based on load and rpm.
Thanks for reminding me. I often forget that I spend most of my time with Speed Density stuff, and the Evo is definitely not Speed Density. Sure wish we could figure out what the load calcs were, or at least find the offset that contains what load cell, or load region, the car is using.
Jul 4, 2006, 10:16 AM
#13
I finally made a few logs today and wanted to try to take a stab at the load formula. I know from my DSMLink experience that it is mainly based off of mass airflow/revolution, along with a few other variables that can change it slightly.
So, looking at my Evoscan logs with the logreader, I came up with this equation which seems to work pretty decently for my car. Maybe a few of you can test it out and see what you come up with:
Load = Maf Hz/ Engine RPM * some variable(s)
For my car I used the "some variable(s)" as a constant of 852, based on a few quick calculations.
So, for example in one of my logs, I was at 1308Hz at 4656 RPM (right at the end of a spoolup after going WOT in 2nd), and my EvoScan log showed timing as 2*.
So, 1308/4656*852=239 So, looking at the 240 load column in my stock map at 4500RPM, the timing value is 2. So that checks out.
Using one more data point: A different run at the top of third I had 1585Hz at 6781 RPM, and the log showed 17* timing.
1585/6781*852=199 So, in the 200 load column in my stock map at 6500, it is 15* timing and at 7000 it is 18* timing. So, 17* checks out there, too.
Obviously, this isn't an exact forumula since I used a constant where I know there are variables, but I think this may help a few people out to get an idea of what there load number is. I know someone already posted how to find what load column you are in, but if this load forumla checks out and you find a constant that seems to work on your setup, you can use the forumla to calculate what load column you are in when you are knocking and how much timing is being pulled as a result.
Eric
So, looking at my Evoscan logs with the logreader, I came up with this equation which seems to work pretty decently for my car. Maybe a few of you can test it out and see what you come up with:
Load = Maf Hz/ Engine RPM * some variable(s)
For my car I used the "some variable(s)" as a constant of 852, based on a few quick calculations.
So, for example in one of my logs, I was at 1308Hz at 4656 RPM (right at the end of a spoolup after going WOT in 2nd), and my EvoScan log showed timing as 2*.
So, 1308/4656*852=239 So, looking at the 240 load column in my stock map at 4500RPM, the timing value is 2. So that checks out.
Using one more data point: A different run at the top of third I had 1585Hz at 6781 RPM, and the log showed 17* timing.
1585/6781*852=199 So, in the 200 load column in my stock map at 6500, it is 15* timing and at 7000 it is 18* timing. So, 17* checks out there, too.
Obviously, this isn't an exact forumula since I used a constant where I know there are variables, but I think this may help a few people out to get an idea of what there load number is. I know someone already posted how to find what load column you are in, but if this load forumla checks out and you find a constant that seems to work on your setup, you can use the forumla to calculate what load column you are in when you are knocking and how much timing is being pulled as a result.
Eric
Jul 4, 2006, 10:21 AM
#14
you've made good headway... the constant should be easy enough to work out in the future, coolant temp, baro pressure, etc.. all affect it slightly, if you start going "off" as temperature chances, you should actually capture that variable and its value affect..
Jul 4, 2006, 10:32 AM
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Originally Posted by l2r99gst
I finally made a few logs today and wanted to try to take a stab at the load formula. I know from my DSMLink experience that it is mainly based off of mass airflow/revolution, along with a few other variables that can change it slightly.
So, looking at my Evoscan logs with the logreader, I came up with this equation which seems to work pretty decently for my car. Maybe a few of you can test it out and see what you come up with:
Load = Maf Hz/ Engine RPM * some variable(s)
For my car I used the "some variable(s)" as a constant of 852, based on a few quick calculations.
So, for example in one of my logs, I was at 1308Hz at 4656 RPM (right at the end of a spoolup after going WOT in 2nd), and my EvoScan log showed timing as 2*.
So, 1308/4656*852=239 So, looking at the 240 load column in my stock map at 4500RPM, the timing value is 2. So that checks out.
Using one more data point: A different run at the top of third I had 1585Hz at 6781 RPM, and the log showed 17* timing.
1585/6781*852=199 So, in the 200 load column in my stock map at 6500, it is 15* timing and at 7000 it is 18* timing. So, 17* checks out there, too.
Obviously, this isn't an exact forumula since I used a constant where I know there are variables, but I think this may help a few people out to get an idea of what there load number is. I know someone already posted how to find what load column you are in, but if this load forumla checks out and you find a constant that seems to work on your setup, you can use the forumla to calculate what load column you are in when you are knocking and how much timing is being pulled as a result.
Eric
So, looking at my Evoscan logs with the logreader, I came up with this equation which seems to work pretty decently for my car. Maybe a few of you can test it out and see what you come up with:
Load = Maf Hz/ Engine RPM * some variable(s)
For my car I used the "some variable(s)" as a constant of 852, based on a few quick calculations.
So, for example in one of my logs, I was at 1308Hz at 4656 RPM (right at the end of a spoolup after going WOT in 2nd), and my EvoScan log showed timing as 2*.
So, 1308/4656*852=239 So, looking at the 240 load column in my stock map at 4500RPM, the timing value is 2. So that checks out.
Using one more data point: A different run at the top of third I had 1585Hz at 6781 RPM, and the log showed 17* timing.
1585/6781*852=199 So, in the 200 load column in my stock map at 6500, it is 15* timing and at 7000 it is 18* timing. So, 17* checks out there, too.
Obviously, this isn't an exact forumula since I used a constant where I know there are variables, but I think this may help a few people out to get an idea of what there load number is. I know someone already posted how to find what load column you are in, but if this load forumla checks out and you find a constant that seems to work on your setup, you can use the forumla to calculate what load column you are in when you are knocking and how much timing is being pulled as a result.
Eric