Is this a case of needing the e38 Manifold Vacuum Patch?

[granatl]

I'm chasing my tail trying to figure out why the car has these random bouts of going ultra lean. I'm wondering if people think I should apply the e38 manifold vacuum patch.
I recently installed FIC 2150 injectors as I was running out of e85 around 18 psi of boost on the previous injectors. In general, I'm running too rich in PE, but getting it closer and closer.
Frames 32009-32047 show it going VERY lean, yet nowhere else is it anywhere near THAT bad.
Since I needed to re-tune for the bigger injectors, I decided to take a mix of DSTeck's guide for doubling stoich and halving "IFR vs. Pressure" and someone's else's comments about NOT touching the MAF numbers (ever), but instead just edit the fueling. So, I took the stock GM MAF curve and left it unmodified.

So, is there something I'm overlooking in my numbers or is the patch exactly what I need?

2010 Camaro, e85, FIC 2150, 7875 Turbonetics turbo, Squash Return Style double pumper

27Sep2015_3.hpt27Sep2015_3.hplJax_2bar_E38__alt.cfg

[granatl]

Adding screenshot...lean.png

[granatl]

The patch DID make a difference.

[schpenxel]

Are you running meth injection by chance? I'm assuming not since you're running E85 but figured I'd ask.

Are you logging fuel pressure?

[schpenxel]

Did you intend for it to be running in mixed mode? It's using MAF and virtual VE right now it looks like

If you want to do that, you first need to dial MAF and VE in one at a time. Your VE table also looks really strange. I've never seen one that flat.

Fuel trims are atrocious on this thing--like -20% averages.. some spots are down under -30%

You need to start with the basics IMO. Use the best injector data that you've got. I like the "double stoich / half IFR" method that you mentioned. Do that. Put it in SD mode, get virtual VE table ironed out. I'd probably not run the MAF unless you just really want to for some reason. It will be next to impossible for fuel trims to be consistently low when running a MAF unless you have very good injector data, which I highly doubt you have, no offense.

[granatl]

Although I have meth injection, it's disconnected. I don't have a transducer (or FPCM) to get the fuel pressure. I think I do have to pursue that though, because I keep wondering how much fuel that Squash system can feed via a -6 line. There are data logs where I'm >200 KPA and bank 2 (the feed line side) stays rich and bank 1 oscillates with narrow valleys. I know narrow band isn't accurate outside their normal range, but it's odd that I see this.

I installed the FIC data as it is on their website. The car idles smooth and drives nice while not in PE.

The reason for the high variance on LTFTs is that I'm not going to touch the MAF curve, but instead trying to do it via "Injector flow mult vs. MAP." I haven't yet figured out a way to mathematically get a good guess for these values. I'm certainly getting closer (since I posted this) though.

Once the car gets to 4k RPM, it doesn't use the VVE any longer. Even so, I'll try some of your suggestions.

[realcanuk]

No clue why you wouldn't fix the maf curve, rather than play with injector data. First time I ever hear to...... "not touch the MAF curve".
Doesn't make any sense to me.

[07GTS]

also your injector offset data is still suited to a non boost referenced fuel system, with your IFR flat lined to suit boost/vac system (assuming your boost referenced) the offset should also have the same row to suit your line pressure in all columns otherwise the ecu is trying to offset what the reg is also offsetting

[SultanHassanMasTuning]

injector data must be correct, PW and mini PW and offsets

and as mentioned you must tune your maf curve/or your VE tables

[granatl]

The reason for not touching the MAF curve is simply an experiment. I read someone's Internet rant about how "everyone does it wrong," so I was curious if it could be done the other way. So GM delivers this nice looking curve and adjusts everything else to fit -- but they have millions in equipment that I don't. Still, I'm seeing how close I can get it and then saving the MAF and VVE for last (so to speak).

I hadn't understood that about the offset. That explains the wackiness. I'll flatten my offsets (by volt row). Does that mean I should switch the Offset Select from "vacuum" to "MAP?"

[10_SS]

You have to dial in the MAF at those airflows just like you want to cal your VE table... GM certainly hasn't calibrated that setup at 18psi worth of airflow. The injector data if originally correct, is still correct at 18psi worth of airflow. Since your so early in the tune, you should convert to the "2bar Map - Speed Density" OS since it's free, and will give you boost tables and a real VE table.

[07GTS]

i have my offsets working fine on the vacuum table and have the map table zeroed out, if u have referenced reg then just the vacuum table will work fine u could use the map one if u needed to go into boost but since the reg is referenced it dose the changes for u, see what ur line pressure is with engine off and copy that column into all others say its 408kpa make all the same as that one and make the 4-5v lines keep the same pattern in stead of zero, IFR v map and IFR v IAT have multipliers also which im not sure are needed usually i only ever see then as 1.0

[07GTS]

also if u doubled stoich then half the IVT terms this will keep the IVT calculation the same as it was otherwise it will think u are super lean and read incorrect, this will also help with the transient tables/IVT gain fueling calculations

[realcanuk]

The reason for not touching the MAF curve is simply an experiment. I read someone's Internet rant about how "everyone does it wrong," so I was curious if it could be done the other way. So GM delivers this nice looking curve and adjusts everything else to fit -- but they have millions in equipment that I don't. Still, I'm seeing how close I can get it and then saving the MAF and VVE for last (so to speak).

I hadn't understood that about the offset. That explains the wackiness. I'll flatten my offsets (by volt row). Does that mean I should switch the Offset Select from "vacuum" to "MAP?"

That person should be ranting in an asylum..... I kind of doubt the whole tuning world does it wrong.

[granatl]

The banter is entertaining -- as I'm not even remotely close to a pro tuner, maybe the guy is nuts. I did MAF curve changes for the first 2 years of HPT on my Camaro -- I'm just experimenting with something different. I'm considering moving the MAF pre-turbo like it used to be, so that I can reconnect the Meth injection and bring down the IAT's. If my hunch is correct, I should be able to move the MAF w/o re-tuning. Whereas before, I think I did have to re-calibrate it (it's been more than a year, so I can't be sure).

I've been told that I have the nicest driving, high horsepower, Camaro out there. Under 1/8 throttle, it drives like a normal car, smooth as glass and gets 19 MPG hwy on e85. So the experiment is just so I learn something new. It'd be easier to just futz with the MAF curve, but I'm getting a chance to learn about some of the other tables that I've never looked at. The injectors are really "too big." I think I've only seen peaks of 35% DC and that will come down once it's not overly rich in PE.

I figured I'd give an update since flattening the offsets.
(Still haven't touched the MAF curve)
All (but one) LTFT is -4% or less. A little more fine tuning of the "Flow Rate Mult vs. MAP" could fix this, but it's not worth tackling right now..
I have my wideband Lambda close to commanded (1/EQ). Still a bit too rich in places, but certainly improving.

I thought I learned from other posts that "PE Throttle/Pedal (HOT)" is dictated by the ETC% (and not TPS%). I have all my PE numbers low, but it looks like instead of 23% pedal, the commanded lambda doesn't drop under 1.0 until 54%. What is the correct PID I should use to match the one utilized by the table -- "ETC Pdl %?"

[10_SS]

my 2010 Camaro E38 is called "PE TPS".

[schpenxel]

The theory is that GM has the MAF curve very accurate due to their super accurate equipment, testing, etc. so then the idea is to change injector data only, instead of the MAF curve, since the MAF curve from GM is already ''correct''

My problem with that theory is the MAF really only reads a SAMPLE of the air going by. It's not like it's a gear driven fluid flow meter where every bit of the fluid going through it is measured.

Change anything before the MAF and you can change how the air is passing through the MAF, which can and will totally throw off the curve GM gave us.

If your injector data is wrong it will never be perfect when running MAF only.

While running SD you at least have so many cells in the VE table that you can unknowingly bake in corrections to correct for bad fuel injector data. There's a cell for every occasion in the VE table I say.. MAF.. not so much.

[10_SS]

I've always wondered why the MAF curve isn't setup more like the VE table... RPM vs Hz table, with Airflow in the cells. Or add a MAF Airflow correction table that has RPM vs MAP.. most would be 1.0... but some cells would have the correction. Seems easy to do. That would be one sweet enhancement from HPT...

[granatl]

my 2010 Camaro E38 is called "PE TPS".

Thanks! This is the one I needed.

[schpenxel]

I've always wondered why the MAF curve isn't setup more like the VE table... RPM vs Hz table, with Airflow in the cells. Or add a MAF Airflow correction table that has RPM vs MAP.. most would be 1.0... but some cells would have the correction. Seems easy to do. That would be one sweet enhancement from HPT...

There's just no reason to if you have proper injector data. Not to mention most would just go SD before bothering with all that. I guess it would be useful though to some people.. though I'd prefer they add boost enrichment tables for the newer ECM's first.. seems they have pretty well stopped custom OS development