How do I increase cylinder airmass axis?

[KFXGUY]

04 ls1 gto. Turbo car. Under boost I easily max out the cylinder airmass axis of 1.20. I have a 2 bar custom OS. I need this so I can control spark differently from low boost to higher boost. Is there a way to do this? Someone said something about messing with injector data to scale? it. It sounded like I would need to retune my whole calibration for that? I really don?t want to do that if there?s another way. But I really need to be able to control my timing better. I leave in first gear on like 3psi which it definitely wants more than 12-13 degrees. Then I shift to second and give it say 7lbs. I may need to take away a degree or so and then third I may run 10.5lbs and need to pull it back to 12-13. Ideas? Thx

[TCSS07]

If it doesn't give you the ability to change it on the spark chart axis to higher numbers then yes you would have to scale the injectors to get back on cyl air mass scale
you can either lower the injector flow rate (which i would use) or lower the flow rate modifier vs volts and yes you'll have to re tune your airflow models but if its spot on you can just remove a set percentage to get close like remove 10% from the injector flow rate and do the same for your maf or ve which ever you use or just remove the fueling from the flow rate first and see how it goes

[KFXGUY]

What am I looking for to change on the spark chart? I’m unfamiliar with what you mean by “give me the ability to change it”. How do I attempt to change it?

[TCSS07]

some ecms give you the ability to change the max amount of cylinder airmass - so open your main ho spark chart and on the axis that has the cylinder airmass if its underlined you can click it and change the numbers but if not it means its hard coded and you cant so scaling the injectors would be the only work around

[KFXGUY]

Thanks for your replies.

So if I scale it, the airmass values don’t actually change, it just changes the regions it now reads in?

[TCSS07]

Correct, if you lower the fuel flow rate you'll drop down on the cylinder air mass scale so instead of maxing out at let's say 1.7 you'll be lower. It sort of tricks the ecm into thinking its flowing less air but you'll have to find the right numbers for your particular setup to get you back on scale

[Ben Charles]

That ECU is older 24x so not bake to edit axis.. so scale is your best bet..
I would do a 50% scale tune and have a 2.40 limit (on top of the 1.20 limit you have now)

[kingtal0n]

I wouldn't scale it if you don't need to.

Simply use afr advance (its always worked for me)
whatafradvdoes.jpg

[KFXGUY]

Well how does that work? Looks like your table goes to 210. Can I get mine to do that?

[kingtal0n]

I don't think you are seeing clearly yet. The scanner goes to whatever you want, that isn't your issue.

The yellow/orange/green box is showing afr advance. look at the axis on afr advance carefully. The units there represent PE mode, like 1.0 to 1.3 is enrichment status. RPM is the scale on the left.

i.e. read the box titled "aFR spark advance correction" and see what you can divulge in that, rpm on the y axis, and afr on the x axis.
for example is afr commanded is "1.2" and rpm is 5200, it will "add" -0.99* of timing (which is a negative number so it takes out a degree of timing)

iirc 14.7/1.2 is the commanded a/f ratio if your base a/f is set to 14.7 (some are 14.5 or whatever)

[KFXGUY]

I don't think you are seeing clearly yet. The scanner goes to whatever you want, that isn't your issue.

The yellow/orange/green box is showing afr advance. look at the axis on afr advance carefully. The units there represent PE mode, like 1.0 to 1.3 is enrichment status. RPM is the scale on the left.

i.e. read the box titled "aFR spark advance correction" and see what you can divulge in that, rpm on the y axis, and afr on the x axis.
for example is afr commanded is "1.2" and rpm is 5200, it will "add" -0.99* of timing (which is a negative number so it takes out a degree of timing)

iirc 14.7/1.2 is the commanded a/f ratio if your base a/f is set to 14.7 (some are 14.5 or whatever)

Ok I overlooked that box. I was looking at the scanner and saw afr correction. Forgive my ignorance, I have not worked my way to this sort of thing yet.

So. The spark correction. I see across the top that must represent my kpa. And then rpm to the left like you said. And this would work great for me, but where do I find this spark correction in my program? I dont have my computer with me so I can’t look through it, are you sure I have this table? I don’t remember seeing it. Thanks for your replies.

[KFXGUY]

I wouldn't scale it if you don't need to.

Simply use afr advance (its always worked for me)
whatafradvdoes.jpg

Ok. I found that table. What do the numbers across the top mean? How can I use this table to retard timing at higher boost? Thx

[5FDP]

You went over his post too quickly, he already said the x axis is PE (EQ Ratio commanded).

[KFXGUY]

You went over his post too quickly, he already said the x axis is PE (EQ Ratio commanded)

Well I should have searched before posting instead of after. So I got that part. But I guess my question should have been, how do I use pe to retard my timing in higher boost kpa areas? Sorry if it’s a dumb question, but right now I’m not seeing how the timing and boost correlate to the pe numbers.

[LSxpwrdZ]

Still easier to scale the tune or use a custom OS that has the ability to adjust spark vs boost.

Problem with the EQ Ratio Spark Correction table is you are relying on boost enrichment to not only command the correct fueling but also now to retard the timing as it goes richer. Boost enrichment isn't instantaneous on most applications so there will be a brief period during a pull in boost transition that it's going to be commanding leaner than you want and overtimed.

[KFXGUY]

Still easier to scale the tune or use a custom OS that has the ability to adjust spark vs boost.

Problem with the EQ Ratio Spark Correction table is you are relying on boost enrichment to not only command the correct fueling but also now to retard the timing as it goes richer. Boost enrichment isn't instantaneous on most applications so there will be a brief period during a pull in boost transition that it's going to be commanding leaner than you want and overtimed.

Yea I’m not going to even try it that way (eq table).

I’m going to see if any of the other custom os available are any better. If not, I’m going to beg plead, bribe the guys at hp tuners to add in an expanded table. I really don’t like rigging up the tune with scaling it. Am I right in saying that all of my kpa and cylinder airmass readings won’t be correct anymore? The table will still read the same maximum numbers on the left but will be in lower cells because of the scaling? Am I right? Thx for the replies. I just want to do this the most correct way I can.

[Ben Charles]

Hp wont be able to extend spark table... it was down to extend spark table or fueling... fueling won ha...

I never use BE.. to slow, just stick to PE table and scale tune and your problem is solved

[lukearmstrong1990]

EFI live has a gen 3 feature that has a custom table in their 2 and 3 bar OS. the table is "spark retard vs. MAP' referenced to RPM. so basically it allows you to set your max cyl airmax axis to as much timing as it will take at the boost value that constitutes 1.20 g/cyl and then use the custom table to further retard timing as MAP increases.

example 1.20 g/cyl E85 at 7psi might take 22 degrees.. then you can use the custom table to, for example, retard 4 degrees at 185KPA resulting in 18 degrees at 12 psi. retard a further 4 degrees at 210KPA resulting in 14 degrees at 16PSI and so on and so forth. I "BELEIVE" HP are currently exploring this. if they're successful it will be splendid because no longer will we have to just "accept" the fact that max cyl airmax timing value is less than it could be on low boost.

only alternative is to as above re-scale the whole tune to move the operating area down the airmass values resulting in less resolution for part throttle and cruise etc.

[KFXGUY]

EFI live has a gen 3 feature that has a custom table in their 2 and 3 bar OS. the table is "spark retard vs. MAP' referenced to RPM. so basically it allows you to set your max cyl airmax axis to as much timing as it will take at the boost value that constitutes 1.20 g/cyl and then use the custom table to further retard timing as MAP increases.

example 1.20 g/cyl E85 at 7psi might take 22 degrees.. then you can use the custom table to, for example, retard 4 degrees at 185KPA resulting in 18 degrees at 12 psi. retard a further 4 degrees at 210KPA resulting in 14 degrees at 16PSI and so on and so forth. I "BELEIVE" HP are currently exploring this. if they're successful it will be splendid because no longer will we have to just "accept" the fact that max cyl airmax timing value is less than it could be on low boost.

only alternative is to as above re-scale the whole tune to move the operating area down the airmass values resulting in less resolution for part throttle and cruise etc.

Yea I really didn’t want to scale it because I’m already compromising my resolution as it is, resulting in a slight surge that’s intermittent when cruising down to a stop.

So. Can I, have a buddy flash in a efiLive operating system and be able to read it back with hp tuners and edit it how I need?

[lukearmstrong1990]

no, that table currently only exists in EFI life. if you read it back with HP it will be in the HEX code but not visible to you.

what your airmass max out at boost wise and how much boost u run high boost?

what timing low and high boost do you want to run