COBB AP/ATR Beta Fuel Scaling

[Enki]

Post your scaling information/experiences here; I'm sadly still waiting for my maps.

[phate]

Subbin. No results here since I'm currently on 93 octane.

[rfinkle2]

@silvapain will have some, as well as Dustin.

I have a map to test, but won't have data until either tomorrow or the weekend.

[djuosnteisn]

I was just testing the maps without changing anything else. Basically to make sure the fuel trims behaved as expected, without any changes in fuel or e85 mix ratio. So far, worked like a charm.

[wolly6973]

Still waiting for Evan to get back to me, but in the meantime...

[kritz]

Rob, If you need another car to increase the testing data shoot me a map.

@rfinkle2

[RichieRichness]

I'll send my maps today. subbed.

[silvapain]

I don't have any MAF datalogs yet, but...

I'm using a map originally tuned for 93 octane pump gas that's been adjusted 40% by David at COBB. The LTFT/STFT combinations are higher than they were on pump gas, but based on discussions in other threads my theory is that it's attributed to the 40% increase in injector pulse width. This means the MAF scale is much more sensitive to errors. A simple MAF cal will fix it.

My CL AFRs are meeting their targets no problem. I'm seeing 1.07 lambda in light cruising (my CL target), and 1.00 lambda at idle in neutral (an AFR target from a yet unexposed fueling table).

I edited my current map in ATR and checked the box for 'keep non-table data' prior to saving. Afterwards I sent it to @David@COBB and he verified the beta changes were kept.

[Enki]

Originally Posted by silvapain I edited my current map in ATR and checked the box for 'keep non-table data' prior to saving. Afterwards I sent it to David@COBB and he verified the beta changes were kept.

Good to know we can still fuck with the maps and keep the scaling intact.

Edit: At least until these settings are exposed via ATR.

[Fobio]

eff you guys in the eye...I'm jelly!

fuck it...I'm gonna go make the run out to that place and get me some E85...

[djuosnteisn]

Here's my initial data, somewhat cleaned up and consolidated:







I did a "maf cal log" last night on the way home, on my current 2 gal e85 mix map. Basically just getting a snap shot of the various fuel trims across the entire maf range. Then i flashed the new 20% scaled map from David this morning... put some miles on the car (commute to work is roughly 25 miles), and did another "maf cal log" on the last road to my work.

I combined both LTFT and STFT for a total trim... and included AFR so you can see that these trims are indeed resulting in the right AFR, and then tried to match the maf curves as close as possible, just to align the various LTFT break points.


Close enough to convince me though... the new "scaled" map is most certainly resulting in more fuel (more negative fuel trims). Roughly 15-17% more.

[silvapain]

Dustin, I should thank you for the info but groan you for the huge-ass graph.

[djuosnteisn]

Originally Posted by silvapain I don't have any MAF datalogs yet, but... I'm using a map originally tuned for 93 octane pump gas that's been adjusted 40% by David at COBB. The LTFT/STFT combinations are higher than they were on pump gas, but based on discussions in other threads my theory is that it's attributed to the 40% increase in injector pulse width. This means the MAF scale is much more sensitive to errors. A simple MAF cal will fix it. My CL AFRs are meeting their targets no problem. I'm seeing 1.07 lambda in light cruising (my CL target), and 1.00 lambda at idle in neutral (an AFR target from a yet unexposed fueling table). I edited my current map in ATR and checked the box for 'keep non-table data' prior to saving. Afterwards I sent it to @David@COBB and he verified the beta changes were kept.

Just cause you didn't say it explicitly... but your running your pump gas maf curve on 100% e85... with the 40% scaling, and indeed it's working as intended, right?

I'm not surprised that the trims are off "slightly", i mean 40% is kinda a shot from the hip unless you used an ethanol content analyzer and got super scientific on it lol. But close to zero, and the fact that your running 100% e on a pump gas maf curve says a ton.

Great to hear

Originally Posted by silvapain Dustin, I should thank you for the info but groan you for the huge-ass graph.

Hahaha, it's not that big, but i can copy and resize if you want me to.

[silvapain]

Originally Posted by djuosnteisn Just cause you didn't say it explicitly... but your running your pump gas maf curve on 100% e85... with the 40% scaling, and indeed it's working as intended, right? I'm not surprised that the trims are off "slightly", i mean 40% is kinda a shot from the hip unless you used an ethanol content analyzer and got super scientific on it lol. But close to zero, and the fact that your running 100% e on a pump gas maf curve says a ton. Great to hear

Correct; I'm on 100% E85 but using the MAF scale I made on straight 93 octane pump gas. As a matter of fact, my entire map is from my pump gas tune, just with some adjusted timing and AFR targets to optimize for E85. No MAF or load adjustments at all.

For reference, I scaled my MAF roughly 39% when I went from pump gas to E85. It's not a linear change, though; E85 needs even more fuel than pump gas at high MAF g/s to hit AFR targets. Therefore my MAF was scaled closer to 45-50% at higher voltages.

[djuosnteisn]

Fucking dope.

[Enki]

Originally Posted by djuosnteisn Just cause you didn't say it explicitly... but your running your pump gas maf curve on 100% e85... with the 40% scaling, and indeed it's working as intended, right? I'm not surprised that the trims are off "slightly", i mean 40% is kinda a shot from the hip unless you used an ethanol content analyzer and got super scientific on it lol. But close to zero, and the fact that your running 100% e on a pump gas maf curve says a ton. Great to hear Hahaha, it's not that big, but i can copy and resize if you want me to.

This can probably be accounted for with seasonal blends; the ethanol content in tank is most likely markedly less now than it would be in the summer time (which may even be dead on).

Honestly, I'd leave it pulling fuel as it is now so that when you switch blends you don't run lean (not that that will hurt anything except power output on pure e).

[rfinkle2]

Originally Posted by silvapain Correct; I'm on 100% E85 but using the MAF scale I made on straight 93 octane pump gas. As a matter of fact, my entire map is from my pump gas tune, just with some adjusted timing and AFR targets to optimize for E85. No MAF or load adjustments at all. For reference, I scaled my MAF roughly 39% when I went from pump gas to E85. It's not a linear change, though; E85 needs even more fuel than pump gas at high MAF g/s to hit AFR targets. Therefore my MAF was scaled closer to 45-50% at higher voltages.

I don't intend to derail this thread, but think your tune is still performing as well as it is because you are pure boost tuning.

Calculated loads will still need manual adjusting (correct me if I'm wrong here) if you just convert an old 93 map and still have some active load comp tables.

[Alpha]

So we just got about 15% more fuel out of the stock injectors with this new Beta software? (Sorry I'm a noob)

[Enki]

Originally Posted by rfinkle2 I don't intend to derail this thread, but think your tune is still performing as well as it is because you are pure boost tuning. Calculated loads will still need manual adjusting (correct me if I'm wrong here) if you just convert an old 93 map and still have some active load comp tables.

Since the MAF is no longer scaled, his calculated load values should be much more reasonable than they ever were when the map was manually adjusted for the fuel.

Logs?

Originally Posted by Alpha So we just got about 15% more fuel out of the stock injectors with this new Beta software? (Sorry I'm a noob)

I don't think we have any injector adjustment stuff in these maps. Correct me if I'm wrong, but I'm pretty sure we are just talking about scaling fuel requirements via scalar instead of MAF (for use eth guys).

Anyone?

[silvapain]

Originally Posted by rfinkle2 I don't intend to derail this thread, but think your tune is still performing as well as it is because you are pure boost tuning. Calculated loads will still need manual adjusting (correct me if I'm wrong here) if you just convert an old 93 map and still have some active load comp tables.

Calculated load is based on MAF g/s and RPM. Load is just another term for Volumetric Efficiency (VE), which is the percentage of actual airflow through the engine at a given RPM compared to the theoretical ideal.

My load values on E85 are all jacked up due to tricking the ECU by scaling the MAF. On the COBB beta map, my MAF isn't falsely scaled, so my load values are 'actual'. Therefore, I don't need to adjust any load-based tables.

Now, at WOT my car will hit higher load values on E85 now than it did with pump gas because I'm making more power. I may need to up my load targets for that reason to hit the boost I want, but I don't have to change it if I don't want.

[Enki]

Originally Posted by silvapain Calculated load is based on MAF g/s and RPM. Load is just another term for Volumetric Efficiency (VE), which is the percentage of actual airflow through the engine at a given RPM compared to the theoretical ideal. My load values on E85 are all jacked up due to tricking the ECU by scaling the MAF. On the COBB beta map, my MAF isn't falsely scaled, so my load values are 'actual'. Therefore, I don't need to adjust any load-based tables. Now, at WOT my car will hit higher load values on E85 now than it did with pump gas because I'm making more power. I may need to up my load targets for that reason to hit the boost I want, but I don't have to change it if I don't want.

I wonder if this will resolve the issues seen over in Dano's boost tuning thread regarding some sort of artificial load limit capping output of the engine no matter what tables are modified.

[silvapain]

Originally Posted by Enki I don't think we have any injector adjustment stuff in these maps. Correct me if I'm wrong, but I'm pretty sure we are just talking about scaling fuel requirements via scalar instead of MAF (for use eth guys). Anyone?

Correct. This beta map from COBB let's those of use running Ethanol blends make one scalar value change and not have to use the MAF scale to 'trick' the ECU into running the correct amount of fuel to hit our AFR targets. This won't gain use any more injector headroom.

[rfinkle2]

Originally Posted by silvapain Calculated load is based on MAF g/s and RPM. Load is just another term for Volumetric Efficiency (VE), which is the percentage of actual airflow through the engine at a given RPM compared to the theoretical ideal. My load values on E85 are all jacked up due to tricking the ECU by scaling the MAF. On the COBB beta map, my MAF isn't falsely scaled, so my load values are 'actual'. Therefore, I don't need to adjust any load-based tables. Now, at WOT my car will hit higher load values on E85 now than it did with pump gas because I'm making more power. I may need to up my load targets for that reason to hit the boost I want, but I don't have to change it if I don't want.

Crappers.. mystyped when I said "adjust calculated load values"... intended to say load axis tables will need tweaking FML.

A big step foreward in ease of use, nonetheless.

[Alpha]

Originally Posted by silvapain Correct. This beta map from COBB let's those of use running Ethanol blends make one scalar value change and not have to use the MAF scale to 'trick' the ECU into running the correct amount of fuel to hit our AFR targets. This won't gain use any more injector headroom.

Gotcha, thanks!

[silvapain]

Originally Posted by Enki I wonder if this will resolve the issues seen over in Dano's boost tuning thread regarding some sort of artificial load limit capping output of the engine no matter what tables are modified.

I certainly hope so. I had no problems hybrid tuning on pump gas before going to E85 and scaling my MAF. The caveat is that I haven't load tuned on pump gas with the latest firmware revision; if the issues we're seeing now are due to a firmware change this won't fix it.

[Enki]

Originally Posted by silvapain I certainly hope so. I had no problems hybrid tuning on pump gas before going to E85 and scaling my MAF. The caveat is that I hadn't load tuned on pump gas with the latest firmware revision; if the issues we're seeing now are due to a firmware change this won't fix it.

One way to find out.

[phate]

Originally Posted by Enki I don't think we have any injector adjustment stuff in these maps. Correct me if I'm wrong, but I'm pretty sure we are just talking about scaling fuel requirements via scalar instead of MAF (for use eth guys). Anyone?

This is essentially an injector "adjustment". Meaning it is fooling the ecu into thinking we are taking in more air than what the MAF curve says, somehow. Of course we don't know the mechanics [yet], but it is the same thing we are doing with MAF scaling for E85. Because the fueling calc is based on the MAF curve, there has to be a multiplier in there somewhere (or actaully a multiplier scale, since the scaling is NOT linear on E85, as silvapain said).

So no actual injector head room was gained, we are just injecting more air per revolution, but without the scaled maf curve.

[djuosnteisn]

Originally Posted by Alpha So we just got about 15% more fuel out of the stock injectors with this new Beta software? (Sorry I'm a noob)

Originally Posted by silvapain ...This won't gain use any more injector headroom.

Unless David has been making tweaks to inj latency, or something along those lines. I have my fingers crossed that he's found a way to actually make the injector open earlier than normal. That means we won't necessarily be "bound" between the intake valve opening and spark ignition events. We would theoretically be able to spray earlier, even with a closed intake valve, and significantly increase or fueling window.

Shit, honestly, i'd be willing to spray fuel at the tail end of the exhaust stroke if i could lol.

[rfinkle2]

Originally Posted by phate This is essentially an injector "adjustment". Meaning it is fooling the ecu into thinking we are taking in more air than what the MAF curve says, somehow. Of course we don't know the mechanics [yet], but it is the same thing we are doing with MAF scaling for E85. Because the fueling calc is based on the MAF curve, there has to be a multiplier in there somewhere (or actaully a multiplier scale, since the scaling is NOT linear on E85, as silvapain said). So no actual injector head room was gained, we are just injecting more air per revolution, but without the scaled maf curve.

IIRC Evan is adjusting injector latency.

[djuosnteisn]

I think david is adjusting tables on fuel mass and latency or something along those lines.

[silvapain]

Originally Posted by Enki One way to find out.

I plan on attempting to load tune on this beta map, or at least hybrid load/boost.

[djuosnteisn]

Thanks finkle for your ninja forums skillz on finding this link:

Have you measured when the injectors...



That post shows the injector opening event hugging the intake valve opening event. So lower VVT and higher spark advance = much shorter fueling window.

[Enki]

Originally Posted by phate This is essentially an injector "adjustment". Meaning it is fooling the ecu into thinking we are taking in more air than what the MAF curve says, somehow. Of course we don't know the mechanics [yet], but it is the same thing we are doing with MAF scaling for E85. Because the fueling calc is based on the MAF curve, there has to be a multiplier in there somewhere (or actaully a multiplier scale, since the scaling is NOT linear on E85, as silvapain said). So no actual injector head room was gained, we are just injecting more air per revolution, but without the scaled maf curve.

There has to be something else involved if the trims/AFRs are staying consistent with only the scalar change. The MAF curve isn't a linear one, so there's no way it could just be a simple scalar value IMO.

Originally Posted by djuosnteisn Unless David has been making tweaks to inj latency, or something along those lines. I have my fingers crossed that he's found a way to actually make the injector open earlier than normal. That means we won't necessarily be "bound" between the intake valve opening and spark ignition events. We would theoretically be able to spray earlier, even with a closed intake valve, and significantly increase or fueling window. Shit, honestly, i'd be willing to spray fuel at the tail end of the exhaust stroke if i could lol.

+1, WTB moar injector

Originally Posted by rfinkle2 IIRC Evan is adjusting injector latency.

On these maps? You sure about that?

[phate]

Originally Posted by djuosnteisn I think david is adjusting tables on fuel mass and latency or something along those lines.

Whatever it is, as long as it works and we don't have crazy load values anymore, I'm down

[Alpha]

Originally Posted by djuosnteisn Unless David has been making tweaks to inj latency, or something along those lines. I have my fingers crossed that he's found a way to actually make the injector open earlier than normal. That means we won't necessarily be "bound" between the intake valve opening and spark ignition events. We would theoretically be able to spray earlier, even with a closed intake valve, and significantly increase or fueling window. Shit, honestly, i'd be willing to spray fuel at the tail end of the exhaust stroke if i could lol.

That's what I was thinking too as I DID hear that they were working on getting us an additional 15%~ out of our stock injectors. (I'm assuming this is being worked on as we speak)

[Enki]

Originally Posted by djuosnteisn Thanks finkle for your ninja forums skillz on finding this link: Have you measured when the injectors... That post shows the injector opening event hugging the intake valve opening event. So lower VVT and higher spark advance = much shorter fueling window.

So we can use simple math to discern effective (current) max spray window based on map values across multiple tables...right?

Also, has anyone dyno proven that there is a benefit/detriment to running VVT values past spoolup?

Originally Posted by Alpha That's what I was thinking too as I DID hear that they were working on getting us an additional 15%~ out of our stock injectors. (I'm assuming this is being worked on as we speak)

This would be awesome and a HUGE step forward for our platform as a whole. You guys think I should update the thread title/OP with information regarding this fueling update as well? Basically make this thread about both fuel scaling and improved injector flow changes?

[rfinkle2]

Originally Posted by Enki There has to be something else involved if the trims/AFRs are staying consistent with only the scalar change. The MAF curve isn't a linear one, so there's no way it could just be a simple scalar value IMO. +1, WTB moar injector On these maps? You sure about that?

No. LOL.... "changes to your injector dwell time and mass of fuel scalar" are being changed.

If dwell time = latency than yes, if dwell time does not = latency than no, I'm not sure.

Bolded type is what is being tweaked.

[djuosnteisn]

Originally Posted by Enki So we can use simple math to discern effective (current) max spray window based on map values across multiple tables...right? Also, has anyone dyno proven that there is a benefit/detriment to running VVT values past spoolup? This would be awesome and a HUGE step forward for our platform as a whole. You guys think I should update the thread title/OP with information regarding this fueling update as well? Basically make this thread about both fuel scaling and improved injector flow changes?

Yup, theoretically simple math. But I think adding VVT in higher rpms (esp on k04) result in drastically reduced maf g/s (e.g. decreased performance). And right now, all this injector control stuff is pure speculation. Nothing has been proven yet, so i'd leave the title as is.



.... until we prove it

[phate]

Originally Posted by djuosnteisn Yup, theoretically simple math. But I think adding VVT in higher rpms (esp on k04) result in drastically reduced maf g/s (e.g. decreased performance). And right now, all this injector control stuff is pure speculation. Nothing has been proven yet, so i'd leave the title as is. .... until we prove it

Yessir. From the little testing I've done, we only saw IDC decrease because the air mass decreased as vvt increased in the higher rpms. On my most recent dyno session (not my car), I played with VVT on the bottom end and it didn't have any sort of effect on power (surprising).

[silvapain]

Originally Posted by Enki There has to be something else involved if the trims/AFRs are staying consistent with only the scalar change. The MAF curve isn't a linear one, so there's no way it could just be a simple scalar value IMO.

A very basic primer on how the ECU determines injector pulse width:

1. The ECU gets a voltage signal from the MAF, and using the MAF scale, turns that into mass airflow (g/s)
2. The ECU determines RPM and calculates load
3. Based on RPM and load, the ECU determines spark advance, VVT, and AFR target
4. Using mass airflow and AFR target, the ECU calculates fuel requirement in mass rate (g/s, lb/hr, whatever)
5. Using a scalar that represents injector size (lb/hr; on DI this would also incorporate fuel rail pressure), the ECU determines required injector pulse width (in milliseconds)

It's the scalar in item 5 that COBB is adjusting I believe. It's a static percentage.