LS7 Trying to Use LTFT Tuning Until...

[Les10]

Hey Les, I Looked at the MAFlog7 and the knock is from the tune not being dialed in. From my observation, timing is a little high in the lighter load area, that mixed with a lean conditions is where you are getting knock. The MAF curve from what you have done so far is looking better! Just going to have to put more fuel to it. If it were me, id highlight the MAF table from 3900Hz on up and multiply it by 1.03 then hit smooth a few times and start from there. Remember though, once you make a change to the tune, drive around for about 15-20 min BEFORE you start logging data.

I noticed that you had a few random instances where your spark dropped like it cut timing. It may also be helpful to log FUEL CUT TORQUE MANAGEMENT TYPE, SPARK TORQUE MANAGEMENT TYPE, ETC TORQUE MANAGEMENT TYPE in your channels. As for going back and forth between MAF & VVE, I'd continue with the MAF tuning until it gets a bit more better. Then I would switch over to VVE.

I appreciate your advice & have added those channels to my Scanner. Those will be part of fixing the knock problem, correct? I think I understand the suggestion to up the MAF table, you are speaking of the MAF Calibration tables, Airflow vs Freq Low & High, correct?

If I tweak the MAF table & continue with the MAF tuning will dialing that in better help with the knock issue or do I need to deal with the knock directly first? As you can tell the knock issue has me concerned.
Thanks!

[LS ROB]

I understand "seeing" the knock is concerning. This is why you have a High Octane and Low Octane spark table. If the ECM senses knock, it will revert to the low octane table. If you want you can flash this in and see how it acts. The attached file has timing reduced and added to the MAF table. I dont suspect this will cure all of the knock but should have you going in the right direction. Remember to drive 15 minutes or so before logging. Its called "rich after flash" if you want to look it up. Also, the more cell hits you can get, the better your data will be.

Just so that you are aware, i am not an actual tuner; just some guy with an ls7 trying to help another guy with a ls7.

MAF Flash7,forMAFlog7-1.hpt

[Alvin]

After installing the new injectors & logging and flashing 7 MAF calibrations with LTFTs I'm at a stalemate with reuslts. I attached my latest flash (MAF Flash7) using Special paste from log (MAFlog7). I also attached my latest flash with SD Reactivated (MAF Flash8), wanting to know if I am properly disabling SD for the MAF logging.

Knock Retard seems to be getting worse as I continue to log. I'm new to computer tuning but have enough experience with old street & race cars to know that knock ain't good. How do I address that? LS Rob suggested I add Cylinder Mass to my Scanner channels & I did.

I know, it's a mess, so where do I go from here?? Should I move on to trying to disable MAF & tune SD??

I attached (MAFlog9) just to show the latest with SD Reactivated. Thanks All!!

It does not look like you are putting it into SD mode. There is a pid you can log that will tell MAF sensor state. Failed, etc. You should also have a P101, 102, or 103 code active for it to be in speed density mode.

I pulled timing out in your problem area just so you can see were it is happening.

The log labled MAF doesn't look too far out of place on the fuel trims. They will never be zero. Having the fueling correct will help with timing but you will have to pull timing in some spots/add in others etc.

MAF Flash8,ReactivateSD.2.hpt

[Les10]

It does not look like you are putting it into SD mode. There is a pid you can log that will tell MAF sensor state. Failed, etc. You should also have a P101, 102, or 103 code active for it to be in speed density mode.

I pulled timing out in your problem area just so you can see were it is happening.

The log labled MAF doesn't look too far out of place on the fuel trims. They will never be zero. Having the fueling correct will help with timing but you will have to pull timing in some spots/add in others etc.

MAF Flash8,ReactivateSD.2.hpt

Thanks You for taking the time to look into my issues.

1) I thought I was tuning MAF or calibrating MAF using the 'Airflow vs Freq' Low & High tables & everthing I read & videos I watched told me that I needed to disable SD which is what I thought I had done. Additionally I was using Fuel Trims to log for this process.

2) I did think the "P101, 102, or 103 code" would come up if I disabled MAF but it was my intention to disable SD so I could tune MAF. So PLEASE tell me if I was going about this all WRONG. If so, I need to stop & regroup.

Thanks

[Alvin]

Thanks You for taking the time to look into my issues.

1) I thought I was tuning MAF or calibrating MAF using the 'Airflow vs Freq' Low & High tables & everthing I read & videos I watched told me that I needed to disable SD which is what I thought I had done. Additionally I was using Fuel Trims to log for this process.

2) I did think the "P101, 102, or 103 code" would come up if I disabled MAF but it was my intention to disable SD so I could tune MAF. So PLEASE tell me if I was going about this all WRONG. If so, I need to stop & regroup.

Thanks

Its likely easier if I just show you..

Look at the differences between this file and yours. * You may need to copy the high octane spark tables into the low * Some OS's (most gen 3, handful of gen 4) default to the low octane table if there is a MAF fault. We are essentially causing a MAF fault so the ECM uses VVE

MAF Flash8,ReactivateSD.3.hpt

[Les10]

I understand "seeing" the knock is concerning. This is why you have a High Octane and Low Octane spark table. If the ECM senses knock, it will revert to the low octane table. If you want you can flash this in and see how it acts. The attached file has timing reduced and added to the MAF table. I dont suspect this will cure all of the knock but should have you going in the right direction. Remember to drive 15 minutes or so before logging. Its called "rich after flash" if you want to look it up. Also, the more cell hits you can get, the better your data will be.

Just so that you are aware, i am not an actual tuner; just some guy with an ls7 trying to help another guy with a ls7.

MAF Flash7,forMAFlog7-1.hpt

Yep, GHuggins had warned me about the "rich after flash" problem before & I realize now I have been trying to rush things. I do appreciate your time & willingness to help another LS7 guy. Z06 or Z28?

How do you get more cell hits? just more driving? Cell Hits Required in the Graph Layout Editor??
Thanks for the Flash, MAF table & timing, great!

Would using a wideband make this altogether simpler?

[Alvin]

You can zero out the injector tip temperature offset and completely do away with the "rich after reflash" issue. Most trucks of this era have this table zeroed out from the factory.

If you care to turn it back on you can after you've done the majority of your tuning.

It's not needed IMHO. If it was injector dynamics, d works, and FIC would offer injector tip temp offset tables. Injector offsets are not tuneable items. Its a dump in the data and go situation.

[Les10]

You can zero out the injector tip temperature offset and completely do away with the "rich after reflash" issue. Most trucks of this era have this table zeroed out from the factory.

If you care to turn it back on you can after you've done the majority of your tuning.

It's not needed IMHO. If it was injector dynamics, d works, and FIC would offer injector tip temp offset tables. Injector offsets are not tuneable items. Its a dump in the data and go situation.

I am at such a disadvantage not knowing the Tuner Lingo. The table in question is "Injector Offset vs Injector Temp"? If so, my table has zeros (0.0000) all across. So then that means I don't need to be concerned with the "rich after reflash" issue??

Thanks

[Alvin]

I am at such a disadvantage not knowing the Tuner Lingo. The table in question is "Injector Offset vs Injector Temp"? If so, my table has zeros (0.0000) all across. So then that means I don't need to be concerned with the "rich after reflash" issue??

Thanks

That's right. Still.. I'd make sure to get plenty of data before making changes. I tell people at least 15 minutes.

[LS ROB]

Yep, GHuggins had warned me about the "rich after flash" problem before & I realize now I have been trying to rush things. I do appreciate your time & willingness to help another LS7 guy. Z06 or Z28?

How do you get more cell hits? just more driving? Cell Hits Required in the Graph Layout Editor??
Thanks for the Flash, MAF table & timing, great!

Would using a wideband make this altogether simpler?

No worries. Yes, more driving time for more hits. The values will count up or down depending on how many hits you get in a particular cell. Example here: lets say your fueling in a particular cell is really -1.25 but you only hit that cell 5 times. Well, that cell could show -5.50 rich. You didn't hit the cell enough times for the value to adjust accordingly. You make the adjustment and on the next log, you show that you are now lean in that area. The more hits = the better. A wideband is very helpful and i recommend getting one. You will need it to tune WOT areas anyways. I'd recommend taking an idle log and watching how the scanner counts the cell hits in real time. That will give you a better understanding on how the fuel trim value is determined. Just above the graph there is some letters A and C. A is for the average which is what you copy/paste into the editor and C is the hit count for the cells.

I did a swap into a 68 camaro, so the ls7 is based off of the Z28 due to the VSS signal from the trans i believe. I cant remember right off what it was exactly but the engine was converted to a wetsump like an ls3 so i didnt have to run all the additional oil lines that you have with a dry sump.

[Les10]

That's right. Still.. I'd make sure to get plenty of data before making changes. I tell people at least 15 minutes.

Thanks!

[Les10]

Its likely easier if I just show you..

Look at the differences between this file and yours. * You may need to copy the high octane spark tables into the low * Some OS's (most gen 3, handful of gen 4) default to the low octane table if there is a MAF fault. We are essentially causing a MAF fault so the ECM uses VVE

MAF Flash8,ReactivateSD.3.hpt

OK, so PLEASE bear with me as I try to explain what I was trying to do. In my mind my whole process was logging to tune MAF so I was disabling SD (per what I thought was proper). My last flash for tuning was ( MAF Flash7,forMAFlog7.hpt ) in which I thought I had disabled SD. The only reason I attached ( MAF Flash8,ReactivateSD.hpt ) was to show how I had reactivated SD & hoping someone could verify if I was doing it right. I am attaching both flashes again to save you time hopefully.

Please let me know if this even makes sense & again if I'm on the right track. I realize my posts are wordy because I'm just learning the Lingo and am trying to explain myself. I am most respectful of you folks, had no idea there was so much to it, and that there were so many different ideas, approaches & ways to skin the cat.

Thanks!MAF Flash7,forMAFlog7.hptMAF Flash8,ReactivateSD.hpt

[Les10]

I understand "seeing" the knock is concerning. This is why you have a High Octane and Low Octane spark table. If the ECM senses knock, it will revert to the low octane table. If you want you can flash this in and see how it acts. The attached file has timing reduced and added to the MAF table. I dont suspect this will cure all of the knock but should have you going in the right direction. Remember to drive 15 minutes or so before logging. Its called "rich after flash" if you want to look it up. Also, the more cell hits you can get, the better your data will be.

Just so that you are aware, i am not an actual tuner; just some guy with an ls7 trying to help another guy with a ls7.

MAF Flash7,forMAFlog7-1.hpt

My car liked your tune. After I flashed it I saw -3 to -6 LTFTs & no Knock Retard. I did a data log & after flashing it I saw better LTFTs and just a little Knock Retard (<1). Attaching before & after logs & the tune I flashed.

Does the LTFT differences between Banks 1 & 2 look related to bad O2 sensors possibly? Is Bank 1 jumping around too much?

[LS ROB]

Bank to bank will show some variance and is normal. However, if there is a significant difference, you will want to look for vacuum and exhaust leaks. The o2's seem to be switching fine. What mods do you have on the car now? Long tubes, stock intake, bigger throttle body etc?

I did see some small knock in a few lean areas but once fueling is closer, that should take care of it. Based on the "3rdRob" log, I tweaked the MAF Low table some more. I also tweaked the PE table and upped the TPS % to 65 so you should be able to hit some of mid load areas. Is the car a manual or automatic and do you like the idle of the car now?


MAF tune 1.hpt

Edit** had to rename the tune. It somehow kept linking the previous version.

[Les10]

Bank to bank will show some variance and is normal. However, if there is a significant difference, you will want to look for vacuum and exhaust leaks. The o2's seem to be switching fine. What mods do you have on the car now? Long tubes, stock intake, bigger throttle body etc?

I did see some small knock in a few lean areas but once fueling is closer, that should take care of it. Based on the "3rdRob" log, I tweaked the MAF Low table some more. I also tweaked the PE table and upped the TPS % to 65 so you should be able to hit some of mid load areas. Is the car a manual or automatic and do you like the idle of the car now?


Attachment 132806

Car is a 6-speed manual 2007 Z06. I have returned most of the car back to stock including exhaust manifolds, intake & throttle body. Only engine mod currently is a Katech 116 cam (220/244 duration, 615/648 lift & 116 LSA). I increased idle speed from 850 RPM to 1000 RPM to make it more stable for logging. Once tuning is done I will return it to 850.

What's the TPS % all about?

Many Thanks!

[LS ROB]

Gotcha. We can leave the idle where it is for now if you want but just know when you lower it back; it will need dialed in more from idling in a different cell area. I'd say its better to go ahead and lower it back but its your choice. If you do lower it back, make sure it will idle on its own before getting out on the road. I would do a couple of throttle blips to see how it catches itself and if no issues, then hit the road. The TPS% allows you to give more pedal before Power Enrichment kicks in (fuel multiplier). We want no fueling corrections while tuning which is why things like DFCO have to be turned off. After tuning, that can be dropped back down to where it was. You can use the gears of the the car to get higher up on the MAF Hz table. Normally, i put mine in 6th on the highway and give it slow steady throttle feathering pulses. Just keep in mind that this is going to get you into new territory that hasn't been tuned yet so it's possible you may pick up a little more knock.

[Les10]

Gotcha. We can leave the idle where it is for now if you want but just know when you lower it back; it will need dialed in more from idling in a different cell area. I'd say its better to go ahead and lower it back but its your choice. If you do lower it back, make sure it will idle on its own before getting out on the road. I would do a couple of throttle blips to see how it catches itself and if no issues, then hit the road. The TPS% allows you to give more pedal before Power Enrichment kicks in (fuel multiplier). We want no fueling corrections while tuning which is why things like DFCO have to be turned off. After tuning, that can be dropped back down to where it was. You can use the gears of the the car to get higher up on the MAF Hz table. Normally, i put mine in 6th on the highway and give it slow steady throttle feathering pulses. Just keep in mind that this is going to get you into new territory that hasn't been tuned yet so it's possible you may pick up a little more knock.

I will put the idle back to 850 in last file before I flash it. Thanks for the concise info on the TPS & the tip on 6th gear data gathering.

[Les10]

Gotcha. We can leave the idle where it is for now if you want but just know when you lower it back; it will need dialed in more from idling in a different cell area. I'd say its better to go ahead and lower it back but its your choice. If you do lower it back, make sure it will idle on its own before getting out on the road. I would do a couple of throttle blips to see how it catches itself and if no issues, then hit the road. The TPS% allows you to give more pedal before Power Enrichment kicks in (fuel multiplier). We want no fueling corrections while tuning which is why things like DFCO have to be turned off. After tuning, that can be dropped back down to where it was. You can use the gears of the the car to get higher up on the MAF Hz table. Normally, i put mine in 6th on the highway and give it slow steady throttle feathering pulses. Just keep in mind that this is going to get you into new territory that hasn't been tuned yet so it's possible you may pick up a little more knock.

Starting to understand getting logging data higher on the MAF Hz table using upper gears & throttle. Flashed latest file after lowering the idle [ MAF tune,LSRobs2nd.hpt ]. Did 25min log [ 2ndfileRob.hpl ]. Copied graph data from log & pasted into new file [ Maf tune,LSRobs2ndfile.hpt ]. Did 30 minute log [ 3rdRobFile.hpl ]. Seeing some KR as predicted.

[LS ROB]

Give this one a go Les. Les MAF tune 1.1.hpt I took out 1* from the spark table and used the MAF data to tweak the MAF. This time when you press the throttle go just a bit more than you have been and remember to do slow pulses of the pedal. Basically, we are trying to lug the car down some using the gears without lugging it too hard, but we haven't hit all of the cells in the MAF Low table yet but we are getting closer.

[Les10]

Give this one a go Les. Les MAF tune 1.1.hpt I took out 1* from the spark table and used the MAF data to tweak the MAF. This time when you press the throttle go just a bit more than you have been and remember to do slow pulses of the pedal. Basically, we are trying to lug the car down some using the gears without lugging it too hard, but we haven't hit all of the cells in the MAF Low table yet but we are getting closer.

Yeah, I was watching the Scanner HZ graph as I was logging yesterday & see how it relates, Thanks