Can you change map resolution for 2 bar?

[KFXGUY]

So I?m using a 2 bar custom os. 2004 gto. I?ve hated how it chopped my ve resolution in half from what it was. I downloaded a 2000 (I think) firebird 2 bar tune from the repository and it?s resolution is way better than mine. Any way to change mine? Examples:

Mine



Firebird

[Ben Charles]

Only way to change it change the OS

[KFXGUY]

I’ve tried every custom os for my computer. The non boost map ones have increase resolution but the two they offer with boost capabilities has this very vague and low resolution ve table. I can’t get the car to run right with this crappy table, the fueling is very erratic, gets bad mileage, surges sometimes and wasn’t like that with the non boost operating system.

[5FDP]

He means change the stock OS but in your case you get what you get and that's it. You won't find a different OS for that computer that will work better.

Earlier computer from 1999-2002 offer far better resolution to the 2 bar and 3 bar tables than the later 2003+ computers from everything I've looked at.

You will just have to get the table as smooth as you can get it and keep closed loop active so the computer can help you through fuel trims. The minor loss in table resolution shouldn't cause you this mainly problems, tons of people get by with great results.

[Bill@HPTuners]

04+ are all this way, not enough room.

[KFXGUY]

He means change the stock OS but in your case you get what you get and that's it. You won't find a different OS for that computer that will work better.

Earlier computer from 1999-2002 offer far better resolution to the 2 bar and 3 bar tables than the later 2003+ computers from everything I've looked at.

You will just have to get the table as smooth as you can get it and keep closed loop active so the computer can help you through fuel trims. The minor loss in table resolution shouldn't cause you this mainly problems, tons of people get by with great results.

Well I’m extremely picky in my drivability tuning. Like if it dips below the target idle speed I won’t be ok with letting it be that way. I’ve smoothed it, and I’ll tell you, the cam I have had caused me more tuning headaches than it’s worth. I even let someone else try and tune it and that didn’t help. He suggested that maybe it has a weak idle because of the stock head. Maybeva leaking valve(s). So I bought 243’s, ported them And had a valve job done. Even upped the compression. Nope. I did get it satisfactory this even for now, but I’m thinking my ecm is taking a dump. I’ll see if it starts acting up and go from there. I’ll either sell this car or do a whole harness/computer/engine/trans swap out of a ls3 camaro, if I can’t get it like I want.

[5FDP]

No computer is perfect, that's why they allow for corrections.

If you're that picky then I don't know what to say because once you mod the engine you are throwing so much out the window with how well you can control things.

Maybe change to a less aggressive camshaft to make it work better. Blaming the computer would be the last thing on my mind.

[kingtal0n]

the boost portion of the VE map does not need to be high resolution.

In fact many systems for example AEM do not intend a full tuning effort of their boost condition, but instead rely on something called 'boost enrichment'.

Using 'BE' one may simply tune the engine at wide open throttle with 0psi of boost to generate the VE curve of the engine,
Then, using a copy and paste method, one simply needs to copy the resulting VE curve for 0psi to all sections of 1psi+

Since an engine's VE with a fully open throttle blade isn't going to change when pressure increases due to boost (only theoretical VE changes) all that remains is to add some % to the already tuned VE curve, and this is what they call "boost enrichment". It is merely an accessory, i.e. 'bells and whistles' that the VE table actually posses some portion where one might further fine tune the resultant VE curve during boost sessions, and not a necessary tuning function.

[KFXGUY]

the boost portion of the VE map does not need to be high resolution.

In fact many systems for example AEM do not intend a full tuning effort of their boost condition, but instead rely on something called 'boost enrichment'.

Using 'BE' one may simply tune the engine at wide open throttle with 0psi of boost to generate the VE curve of the engine,
Then, using a copy and paste method, one simply needs to copy the resulting VE curve for 0psi to all sections of 1psi+

Since an engine's VE with a fully open throttle blade isn't going to change when pressure increases due to boost (only theoretical VE changes) all that remains is to add some % to the already tuned VE curve, and this is what they call "boost enrichment". It is merely an accessory, i.e. 'bells and whistles' that the VE table actually posses some portion where one might further fine tune the resultant VE curve during boost sessions, and not a necessary tuning function.

That really isn’t my issue. I’m ok with the crappy boost resolution, I’d like better resolution under 100kpa for normal driving and idle and decel conditions. The lowest kpa I’m offered with this map is 30kpa and under decel my engine would go lower than that. It hits 30kpa on other conditions which would be lean if I set it to not be super rich on decel and visa versa. This is when I’m out of dfco range. Which is most lower speed driving.

[KFXGUY]

04+ are all this way, not enough room.

Not enough room for what? I looked up the 05-06 gto ve maps and they don’t get the resolution cut like mine.

[5FDP]

E40 computers are different than P59 that have less memory/space in the computer file.

[kingtal0n]

That really isn’t my issue. I’m ok with the crappy boost resolution, I’d like better resolution under 100kpa for normal driving and idle and decel conditions. The lowest kpa I’m offered with this map is 30kpa and under decel my engine would go lower than that. It hits 30kpa on other conditions which would be lean if I set it to not be super rich on decel and visa versa. This is when I’m out of dfco range. Which is most lower speed driving.

hmm. Install a huge cam, that should keep it out of the 30kpa- range

[cobaltssoverbooster]

in order to be able to expand the range of the table you must have enough ram in the ecu to hold the coding for the new matrix size, plus its populated data, and any accessing code that needs to be addressed.
there are a lot of ecu's that dont get the OS upgrades we want because there just insn't enough internal storage to hold everything we want. P59 is a good example...that boosted ve table is complete ass

[kingtal0n]

all its rlly missing is 20kpa row. i've zero'd out my 10kpa row.

and ive set dfco to come on at 28kpa

so 2kpa difference?

come to think of it. When tuning my 20-30kpa region I did some 'tuning' in the injector global table as well. If the global injector table has a 20kpa row- there is your 30kpa multiplier to remove fuel for 20kpa sessions.

theres always a way around these little nit picks.

[Ben C]

all its rlly missing is 20kpa row. i've zero'd out my 10kpa row.

and ive set dfco to come on at 28kpa

so 2kpa difference?

come to think of it. When tuning my 20-30kpa region I did some 'tuning' in the injector global table as well. If the global injector table has a 20kpa row- there is your 30kpa multiplier to remove fuel for 20kpa sessions.

theres always a way around these little nit picks.

Nope, it's missing half of the values in between Min and Max meaning the pcm has to interpolate between bigger jumps between cells

[kingtal0n]

Nope, it's missing half of the values in between Min and Max meaning the pcm has to interpolate between bigger jumps between cells

oh specifically how it goes in 10's. Yes i agree that is disheartening however with the number of VE modifiers available (unlike a stand-alone which typically only has a few) it should still be possible to get something satisfactory done. The VE tends to be somewhat flat, no large changes from cell to cell usually, so smooth from here0 to there10 is technically just as smooth as when I add breakpoint in between at 5. I see what you are saying how it might seem inconvenient for tuning however keep in mind the scanner and logging functions can still log in 5's or even 1kpa cells, making exact pinpoint a/f monitoring/changes stilll possible even with a reduced resolution VE map.

Anyways. I don't see it as such a large hurdle. It could be worse... there are plenty of other things that could be worse. You know how sometimes you might hear "if they do everything right, then nobody notices anything" well for the most part I feel like we don't notice much and these tiny uncontrollable 'noticeable details' get scrutinized to blown out proportions because there isn't much to complain about in the grand scheme of everything that could have gone wrong but didn't.

[Chris@HPTuners]

As Bill said, its a limitation in the amount of free calibration space we had in the PCM for the bigger 2x size table. It just didn't fit, hence the smaller half resolution table.

[KFXGUY]

Nope, it's missing half of the values in between Min and Max meaning the pcm has to interpolate between bigger jumps between cells

Yep, exactly. and that causes erratic behavior. Id be ok with low resolution boosted region....even low resolution above 70Kpa....but idle really needs to be better.

[KFXGUY]

oh specifically how it goes in 10's. Yes i agree that is disheartening however with the number of VE modifiers available (unlike a stand-alone which typically only has a few) it should still be possible to get something satisfactory done. The VE tends to be somewhat flat, no large changes from cell to cell usually, so smooth from here0 to there10 is technically just as smooth as when I add breakpoint in between at 5. I see what you are saying how it might seem inconvenient for tuning however keep in mind the scanner and logging functions can still log in 5's or even 1kpa cells, making exact pinpoint a/f monitoring/changes stilll possible even with a reduced resolution VE map.

Anyways. I don't see it as such a large hurdle. It could be worse... there are plenty of other things that could be worse. You know how sometimes you might hear "if they do everything right, then nobody notices anything" well for the most part I feel like we don't notice much and these tiny uncontrollable 'noticeable details' get scrutinized to blown out proportions because there isn't much to complain about in the grand scheme of everything that could have gone wrong but didn't.

I got it real close now, its much more stable. I'm just very picky and like it perfect. If this was a race car, I'd idle it higher and call it good. Its a partial daily driver (i drive it 2-3 times a wekk to work) so i just like it to be as good as possible.

[kingtal0n]

I also drive everyday with 1 car only. My first and only V8 LS engine ever is my first hptuners attempt (2016~) daily now for almost 20,000 miles since turbo 5.3 4l80e segmented flex fuel 411. I've used six or seven stand-alones prior and coming to this was straightforward for the most part because all pressure stand-alone emphasize is MAP->Injector train of thought and that is what the VE map represents for each RPM breakpoint. Some stand-alones have pitiful fuel maps even worse than the one shown in the thread. The factory ECU is just straight up complicated/complex presumably because the engineers needed to emphasize emission control and mileage to an increasingly strict standard. There are too many dependent variables in charge of global gains. Hptuners does extremely well for the most part, de-convolutes this link between us and ecu, so we can actually re-program the ecu to suit our needs instead of using it as a doorstop (without hptuners that is what a GM ecu would be to me at least). We have to remember that it isn't the hptuners inventors who are responsible for the factory ecu complexity/shortcomings, they didn't invent/create the factory computers we use or control the size of the fuel map shown. They just help us dramatically smooth the process of re-programming of it for the most part and many times in control systems there are no one single answer, its up to the designer to implement 1 of an infinite number of strategies and I get the feeling of being extremely well organized and tested, of this there is no question.

That said, the key to take away is how much simpler a typical stand-alone is than the GM ecu. I could very easily argue that the factory ECU is more powerful and stable, and dare I say robust, than a typical stand-alone, especially newer factory computers. The thing those control theories do not seem to account for however is the risk of adding components. We can always add more sensors to make things more stable. But each sensor adds mathematics, formulas, lengths of text, and at some point you are going to have too many sensors for practical application to be reliable, due to the interweb of calculations proposed to affect the model when sensors themselves are not reliable enough yet. So it is also nice to be able to disable features and disconnect dependencies. Like when we disable the maf sensors. Whew, that is one less input to worry about.