Specific ECU FLash tuning questions

[futurevr4man]

To start, here is a very short list of my mods:

3.75L
dual td05/td06 20g's
stage III heads
FMIC
550cc injectors (currently upgrading to 1200cc's)
3.75" Z06 maf in blowthru
anything else needed to support this stuff

when i began logging with my 550's, everything was generally fine. start/cruised like a factory car with just the injector scaling and batter voltage latency changed to fit my denso 550's. i messed with the antilag a bit and built 8psi easily. the follow questions are based off this limited experience.

** i understand that the last cell takes the value of whatever comes after it **

-load
there is a limiting (safety) switch for load. i know this, and i generally understand how it works. My question comes in with, does anything else access this table? i wasnt logging 2-byte load at the time so idk what numbers i was hitting, however, i maxxed out the table before 6000rpm's consistently. if i gave only 70% (just throwing out a random number) throttle then i could rev it out all the way to redline. if i kept it floored, i would get to about 5700rpm (changed with temperature of the air outside, obviously) and it wouldnt go any higher... like a soft cut of sorts.

to restate, my question is if i change this table, does another piece of code work off this "fuel cut double mod" table? is there a reason why i cant just change the load to like 500 (its 198 at the 6000rpm cell)? what about the "target engine load table A/B"?

-AFR
so greg, you said to use the VE efficiency table to change fuel. well, with 1200cc injectors, changing even 1% is DRASTICALLY different than someone with more commonly sized injectors (550's or even 680's). should i use the big high octane table and just modify my fuel that way? i am fine with doing it like that, just seeing if there is another way im not thinking of...

-airflow
so my airflow maxes pretty much immediately.

here is a log of a 1-2-3 pull i did. the rpms are stopping around that 6000rpm mark, and ignore the knock... it was 9 counts at the highest. it was one of my first pulls.



the dark blue line is my airflow, and you can see that it is maxed almost immediately (looking on my computer, its around 4100rpm in 2nd and 3rd that it maxes). do i need to change my "maf smoothing (VE) table"? again, i understand it takes the VE of that 1600hz cell for the rest of the RPM's

-antilag/launch control (same thing in this)
my questions with this have to do with how things are labeled in ecuflash. i am going to list all of them and a 'dumbed down' version of what i think they mean. please correct me if my understanding is wrong, because i think it is on one or two of them.

- stationary rev limit: this is one i am confused on. right above it is "rev limit (normal)" so does stationary rev limit mean that during launch control, it cannot go above this limit at all?
- stationary limit switch speed: the launch control wont activate over this speed (mph)
- minimum throttle %: you have to exceed this number for launch control to activate
- antilag start rpm: it will pull the amount of timing you tell it to in the "antilag ignition retard" section
- antilag ignition retard: this is another section im not sure about... is this telling the ecu to "pull this much timing from the current timing" or is the ecu setting timing to the amount you put in this box? for instance, if i have -10 in the box, is the ecu pulling ten degrees of timing from the amount it runs normally, or is it setting timing to a set -10 degrees while in launch control?
- antilag ignition retard limit: the way i understand this, timing will get pulled to this limit at the very most, but again, is timing being set to this at the "stationary rev limit" or what? linearizing between the start rpm and the rev limit? i hope im making sense.
- antilag AFR: the "AFR" you want your engine to shoot for while in launch control. its not an ACTUAL AFR, its just a reference... you can make it leaner or more rich

i know you told me once greg to go with the settings you have already in there, but because of my engine and turbo size, its just not a good match for my car... so do you have any personal recommendations for my specific setup? i have some settings in mind already, and i would like to see how they match up.

sorry for the book folks, but these questions have been eating at me for some time. i am reading merlin's huge PDF on tuning evo's and in general i have been reading a lot about tuning. i have a good grasp on it all, but these things are still cloudy for me. i will gladly try to expand my thoughts on any of them if i was not clear enough the first time (especially the launch control section).

thanks for your constant help, greg. VERY appreciative! many a beer will be bought for you at NG

[Greg E]

i wasnt logging 2-byte load

That's what you need to be logging. Don't even bother logging the normal airflow and load requests.
For now anyway... I already worked out a mod to stuff the 2-byte variable into a 1-byte space.

You just gave me an idea. For some reason people keep logging those 1 byte requests and asking the same questions you are here. Maybe in the next chrome version I'll replace them with the new "stuffed" address and eliminate the 2-byte requests. Easier to guys who are new to this to understand.

to restate, my question is if i change this table, does another piece of code work off this "fuel cut double mod" table? is there a reason why i cant just change the load to like 500 (its 198 at the 6000rpm cell)? what about the "target engine load table A/B"?

That's for the stock boost controller. It doesn't target boost, it targets airflow.

http://www.3sgto.org/showthread.php?...l=1#post211656

so greg, you said to use the VE efficiency table to change fuel. well, with 1200cc injectors, changing even 1% is DRASTICALLY different than someone with more commonly sized injectors (550's or even 680's). should i use the big high octane table and just modify my fuel that way? i am fine with doing it like that, just seeing if there is another way im not thinking of...

Think of the fuel table more like your target airflow table and the VE table like an SAFC. The higher the numbers you make on the right hand side of the VE table, the more fuel you are telling the ECU to add. Lower numbers = leaner.

I know the VE table only goes to 1600hz and one of the future chrome mods are to extend this table to go all the way to 2800 to give the user the ability to fine tune higher airflow numbers. For now, all you got to work with is just the last cell in that table.

There's nothing wrong with just using the fuel table and disregarding the intake tables all together. That's the way the EVO guys tune their cars. It works just as well. In the end, it's about getting your IPWs to give you the desired AFR you want. To me though, it make more sense to tune the intake tables since those are the ones with the incorrect values for your turbo/intake setup. It also makes tuning your target AFR easier when you got switchable fuel maps too.

so my airflow maxes pretty much immediately.

Again, log the 2-byte stuff.

- stationary rev limit: this is one i am confused on. right above it is "rev limit (normal)" so does stationary rev limit mean that during launch control, it cannot go above this limit at all?
- stationary limit switch speed: the launch control wont activate over this speed (mph)
- minimum throttle %: you have to exceed this number for launch control to activate

It's the rev limit when your speed is less than 6mph (limit switch speed) and your throttle is less than 80% (min throttle percent). Basically, while the car is stationary with your foot planting the gas pedal to the floor.

Don't worry, everyone has a hard time grasping this the first time. Go try it. Car at a stand still, FIRMLY floor the gas pedal.

- antilag start rpm: it will pull the amount of timing you tell it to in the "antilag ignition retard" section
- antilag ignition retard: this is another section im not sure about... is this telling the ecu to "pull this much timing from the current timing" or is the ecu setting timing to the amount you put in this box? for instance, if i have -10 in the box, is the ecu pulling ten degrees of timing from the amount it runs normally, or is it setting timing to a set -10 degrees while in launch control?
- antilag ignition retard limit: the way i understand this, timing will get pulled to this limit at the very most, but again, is timing being set to this at the "stationary rev limit" or what? linearizing between the start rpm and the rev limit? i hope im making sense.

The ECU has a limit on how far back the timing can be retarded during a knock situation. This is a NEW limit to get around that so ignition can happen waaaaay later in the ignition cycle. How far back is this new limit is called the Anti-lag retard limit. This new limit is only in place during launch control NOT normal driving.

Antilag ignition retard is the actual timing degree itself you want during launch control.

I put in the antilag start rpm because I found during testing that the engine would just die long before it ever got up to the Stationary Rev Limit. This at least gave the motor a chance to rev high enough before you started screwing with the ignition.

- antilag AFR: the "AFR" you want your engine to shoot for while in launch control. its not an ACTUAL AFR, its just a reference... you can make it leaner or more rich

You got it!

i know you told me once greg to go with the settings you have already in there, but because of my engine and turbo size, its just not a good match for my car... so do you have any personal recommendations for my specific setup? i have some settings in mind already, and i would like to see how they match up.

You gotta test it at the track. Toni saw WORSE 60ft times from massive wheel spin with these settings at NG this year. He was running 15Gs with better tires than me too. More conservative settings might have helped. Just one of those things you need to play with to tailor to your car depending on the track/weather that day.

sorry for the book folks, but these questions have been eating at me for some time. i am reading merlin's huge PDF on tuning evo's and in general i have been reading a lot about tuning. i have a good grasp on it all, but these things are still cloudy for me. i will gladly try to expand my thoughts on any of them if i was not clear enough the first time (especially the launch control section).

thanks for your constant help, greg. VERY appreciative! many a beer will be bought for you at NG

No such thing as a stupid question. This is all very new to all you guys and it's a LOT to take in. It's not all going to sink in right away.

[futurevr4man]

That's what you need to be logging. Don't even bother logging the normal airflow and load requests.
For now anyway... I already worked out a mod to stuff the 2-byte variable into a 1-byte space.

You just gave me an idea. For some reason people keep logging those 1 byte requests and asking the same questions you are here. Maybe in the next chrome version I'll replace them with the new "stuffed" address and eliminate the 2-byte requests. Easier to guys who are new to this to understand.

yeah ill mess with the 2-byte stuff next time i log. i tried to log load, but it wasnt working, but maybe it was 1-byte. i cant remember anymore.

That's for the stock boost controller. It doesn't target boost, it targets airflow.

http://www.3sgto.org/showthread.php?...l=1#post211656

are you referring to the target engine load table A/B? i am mainly just trying to get away from the table thats for safety for my engine so i can make a full pull. i thought it was the "fuel cut double mod" table? i dont know how high my load actually is, so it would be a real pain to have to change that over and over again, reflashing every time... i want to just set it to some unattainable load (like 500 or something) and do a full pull, then ill change it back to where it should be at. does that make sense?

Think of the fuel table more like your target airflow table and the VE table like an SAFC. The higher the numbers you make on the right hand side of the VE table, the more fuel you are telling the ECU to add. Lower numbers = leaner.

i understand this, but like i said, 1% is A LOT of fuel on 1200cc's!

I know the VE table only goes to 1600hz and one of the future chrome mods are to extend this table to go all the way to 2800 to give the user the ability to fine tune higher airflow numbers. For now, all you got to work with is just the last cell in that table.

There's nothing wrong with just using the fuel table and disregarding the intake tables all together. That's the way the EVO guys tune their cars. It works just as well. In the end, it's about getting your IPWs to give you the desired AFR you want. To me though, it make more sense to tune the intake tables since those are the ones with the incorrect values for your turbo/intake setup. It also makes tuning your target AFR easier when you got switchable fuel maps too.

im really glad you are extending that table. that should be very helpful. i will mess with the intake table, just the last 3 cells give or take, and if i need more fuel up really high... then i have the fuel tables i can adjust.

It's the rev limit when your speed is less than 6mph (limit switch speed) and your throttle is less than 80% (min throttle percent). Basically, while the car is stationary with your foot planting the gas pedal to the floor.

did you mean "greater"? launch control only comes on when its greater than that percentage (87% for instance). and my launch control worked fine, the thing thats getting me is that the way you are describing it, why is there another box under limits called "rev limit (normal)"? are they just reiterating eachother at that point? i think im still being dumb here...

The ECU has a limit on how far back the timing can be retarded during a knock situation. This is a NEW limit to get around that so ignition can happen waaaaay later in the ignition cycle. How far back is this new limit is called the Anti-lag retard limit. This new limit is only in place during launch control NOT normal driving.

so i cannot have my ignition retard less than the limit i suppose? i guess it makes sense, its a little iffy to me though. not sure what the disconnect in my brain is...

Antilag ignition retard is the actual timing degree itself you want during launch control.

the settings it comes with is like -10 i think... wouldnt you want a positive ignition timing, like say 5 degrees BTDC? having the spark so late wont help to build boost i wouldnt think? am i being dumb again?

You gotta test it at the track. Toni saw WORSE 60ft times from massive wheel spin with these settings at NG this year. He was running 15Gs with better tires than me too. More conservative settings might have helped. Just one of those things you need to play with to tailor to your car depending on the track/weather that day.

that makes sense

[futurevr4man]

on the fuel cut double mod, maybe i should just make the timer really really long, figure out my load im hitting, then set my load on the double mod, and change the timer back (in that order)?

[Greg E]

on the fuel cut double mod, maybe i should just make the timer really really long, figure out my load im hitting, then set my load on the double mod, and change the timer back (in that order)?

That's what I do.

[Greg E]

are you referring to the target engine load table A/B? i am mainly just trying to get away from the table thats for safety for my engine so i can make a full pull. i thought it was the "fuel cut double mod" table? i dont know how high my load actually is, so it would be a real pain to have to change that over and over again, reflashing every time... i want to just set it to some unattainable load (like 500 or something) and do a full pull, then ill change it back to where it should be at. does that make sense?

Ignore every single table in the TURBO section. Those are all the tables that operate the stock BCS. Pretty sure you're not using that.

i understand this, but like i said, 1% is A LOT of fuel on 1200cc's!

It's not adding 1% more fuel. It's a mutlipler off the airflow scaling table. Don't fear the numbers.

did you mean "greater"? launch control only comes on when its greater than that percentage (87% for instance). and my launch control worked fine, the thing thats getting me is that the way you are describing it, why is there another box under limits called "rev limit (normal)"? are they just reiterating eachother at that point? i think im still being dumb here...

Durrr... Yes. (dunce hat) "greater than" not less.

Rev limit (normal) is your normal redline while driving.

so i cannot have my ignition retard less than the limit i suppose? i guess it makes sense, its a little iffy to me though. not sure what the disconnect in my brain is...

You got it. If you do set the retard less than the limit, it'll just use the limit value.

the settings it comes with is like -10 i think... wouldnt you want a positive ignition timing, like say 5 degrees BTDC? having the spark so late wont help to build boost i wouldnt think? am i being dumb again?

You could try that. The idea is to get as much unburnt exhaust as possible thru the turbo to get it to spin up.

[futurevr4man]

ok, i believe i understand it all now. thank you for your responses!

[Greg E]

Yeah man! Good questions!