TDStuart Tuning Adventure

[deanm11]

Thank you for all the ideas in this thread, particularly around simplifying mapped points. Taking all the input, I have a new starting point that I am hoping is ready to make some adjustments to VE on my 2022 GT FBO Comp Cams/Holley Intake car.

I have very similar looking mismatches to tdstuart in two areas [ETC Torque Request > Engine Brake Torque] & [Desired Airmass > Actual MAF] at many times. At times the inferrred Baro is low/light but not off as often as the other metrics are in discrepancy. Latest tune attached where I've done the following. I can start a new thread but thought it was on point being the same cams though I have the high rpm oriented intake manifold. I'm running a soler 95mm round throttle body (ZR1 Corvette based) I'm around 520rwhp on a dynojet on pump E85.

I retuned my MAF with the switch that makes the input be pure MAF signal.. it resulted in a 5% or so shift. Previously I had tuned off trims without makgin that temporary switch. When I did this, I do tend lean and the trims take some time catching up hit targetted lamda. That says in those regions VE is too low. When I tuned with the normal blend of VE input, I had to push MAF higher than reality in order to overcome the (partial) low input of the VE side.

I looked to existing mapped points that have similar cam angles to where I wanted to end up. I am now going with 14/15 idle/light load/decel, 18/19/20 cruise and 23/24/25/26 OP. I need 4 for OP as my dyno optimized cam settings don't get to the right numbers at all RPMS by interpolating between two MPs. 4 covers it at least from 3000rpm or so. I made snap lines 14-15, 18-19,19-20, 23-24,24-25,24-26. Emissions and FE are disabled. To start, I didn't make too much change the stock distance tables but instead just made the existing mapped point arrays use the MPs I'm now using. It's a rough start. I've turned throttle feedback off in preparation and did a little drive (no log yet) and it runs quite good. I think I can tel the throttle feedback is not there at parking lot speeds sometimes.

I took engineermike's suggestions for MPs in general
14 0,0
15 20,0

18/19/20 - kind of light to higher load crusing and generally moving the angles in the direction of where they should be when it crosses over to OP.

23-26 - matching my OP angles at 3500, 5500, 6500, 8200rpm

I did a few adjustments to driver demand and the Torque/Inverse to attempt to make
them be more realistic for my power. I used my dyno data at first. It seemed to go a little too far so I dialed it back some by hand.

Finally, I copied the Spark/VE and Torque tables from MPs that were close to the angles that I am using at my new Mapped points. E.g I went from:

0 to 14
1 to 15
7 to 18
8 to 19
13 to 20
25 to 23/24/25/26

I feel like I will only really need to do substantial work in isolating 4 MPS - 18/19/20/25

I think 0/1 are fine they way there as long as the car feels nice and smooth (and it already does)

Tune the 3 cruise points. I will dial in fuel economy by adjusting the angles for those points too.

Then 25 should be fine to copy to all for OPs as it wil have unique data at various RPMs... UNLESS the reall VE data across my optimum OP tune can't be represented in a VE that is smooth enough to be described by the quadratics.

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[tdstuart]

Thank you for all the ideas in this thread, particularly around simplifying mapped points. Taking all the input, I have a new starting point that I am hoping is ready to make some adjustments to VE on my 2022 GT FBO Comp Cams/Holley Intake car.

I have very similar looking mismatches to tdstuart in two areas [ETC Torque Request > Engine Brake Torque] & [Desired Airmass > Actual MAF] at many times. At times the inferrred Baro is low/light but not off as often as the other metrics are in discrepancy. Latest tune attached where I've done the following. I can start a new thread but thought it was on point being the same cams though I have the high rpm oriented intake manifold. I'm running a soler 95mm round throttle body (ZR1 Corvette based) I'm around 520rwhp on a dynojet on pump E85.

I retuned my MAF with the switch that makes the input be pure MAF signal.. it resulted in a 5% or so shift. Previously I had tuned off trims without makgin that temporary switch. When I did this, I do tend lean and the trims take some time catching up hit targetted lamda. That says in those regions VE is too low. When I tuned with the normal blend of VE input, I had to push MAF higher than reality in order to overcome the (partial) low input of the VE side.

I looked to existing mapped points that have similar cam angles to where I wanted to end up. I am now going with 14/15 idle/light load/decel, 18/19/20 cruise and 23/24/25/26 OP. I need 4 for OP as my dyno optimized cam settings don't get to the right numbers at all RPMS by interpolating between two MPs. 4 covers it at least from 3000rpm or so. I made snap lines 14-15, 18-19,19-20, 23-24,24-25,24-26. Emissions and FE are disabled. To start, I didn't make too much change the stock distance tables but instead just made the existing mapped point arrays use the MPs I'm now using. It's a rough start. I've turned throttle feedback off in preparation and did a little drive (no log yet) and it runs quite good. I think I can tel the throttle feedback is not there at parking lot speeds sometimes.

I took engineermike's suggestions for MPs in general
14 0,0
15 20,0

18/19/20 - kind of light to higher load crusing and generally moving the angles in the direction of where they should be when it crosses over to OP.

23-26 - matching my OP angles at 3500, 5500, 6500, 8200rpm

I did a few adjustments to driver demand and the Torque/Inverse to attempt to make
them be more realistic for my power. I used my dyno data at first. It seemed to go a little too far so I dialed it back some by hand.

Finally, I copied the Spark/VE and Torque tables from MPs that were close to the angles that I am using at my new Mapped points. E.g I went from:

0 to 14
1 to 15
7 to 18
8 to 19
13 to 20
25 to 23/24/25/26

I feel like I will only really need to do substantial work in isolating 4 MPS - 18/19/20/25

I think 0/1 are fine they way there as long as the car feels nice and smooth (and it already does)

Tune the 3 cruise points. I will dial in fuel economy by adjusting the angles for those points too.

Then 25 should be fine to copy to all for OPs as it wil have unique data at various RPMs... UNLESS the reall VE data across my optimum OP tune can't be represented in a VE that is smooth enough to be described by the quadratics.

Haven’t read all of this but if you are still having problems with cams and airflow dm me and I’ll give you the solution big tuners use which may help you.

Good job on the tuning tho!

 

[engineermike]

@tdstuart, is it a calibration solution or a hack/shortcut?

@deanm11 I took a look at your file and have a few comments. Take this with FWIW, but one advantage of mapped point simplification is that you have less mapped points to tune. And if you follow Roush's example, which is a good one to follow, you have snap lines between all the points in the flow path which means you're only weighting 2 mapped points at a time. If that's what you're shooting for then here are my comments regarding the mapped point layout:

• I'm not sure I follow the logic of disabling FE. Have you confirmed it's using the desired schedules when you want? I've set mine up to skip drivability so it lives in either stability, FE, or OP. But with yours I'm looking at the breakpoints and it looks like max load for stability is .31, but min load for drivability is .72 to .88 while 0.6 puts it in OP. If it's following these it's in stability to below .31 load, never-never land between .31 and .6, and OP above .6. I don't know how the logic is using these breakpoints to determine which VCT schedule to use.
• There seems to be some snap lines missing, like MP15 to 18, and 20 to 23 or 24.
• I don't see where your MP19 and 20 are even necessary. You could add a snap line from 18 to 26 and have it ride that line as it transitions from light load to OP.
• Your MP18 is at 20, 40. I don't have solid data to back this up but I I'd considering moving this one a little closer to home with your aftermarket cams.
• Your MP25 is directly between 24 and 26. If you added a snap line from 24 to 26, then 25 wouldn't need to exist.
• Some of your OP cam timing doesn't seem to line up on the mapped point 23 to 24 snap line. You could make some small tweaks to the exhaust cam in that region and get on the snap line without any real detriment to the torque output.

That said, I would be awesome if HPT or PCMTec had a mapped point graphing function so you can see how these are laid out and how it's flowing.

 

[engineermike]

This is a quick-n-dirty representation of your mapped points and snap lines:

This is what I'm proposing (sorry for the quality):

 

[deanm11]

This is a quick-n-dirty representation of your mapped points and snap lines:

This is what I'm proposing (sorry for the quality):

Thank you very much for the review and suggestions. It all makes sense to me on first read. I will likely fully adopt before I get to the first logging/VE tweaking. MP18, like back to 10,30 or 10,20 (?) Very generous of you to provide this input. Thanks. It may be some weeks before I get to tuning on this given other priorities.

 

[engineermike]

MP18, like back to 10,30 or 10,20 (?)

Good question. I don't know. First of all, the only reason Ford pushes the cams retarded at cruise is for fuel economy. Retarding the exhaust cam extends the power stroke, while retarding the intake cam requires higher MAP to achieve desired torque, resulting in less pumping losses. It's sets up a pseudo-Atkinson cycle. What I did learn is that I tried running OEM FE cam timing on a Whipple car at cruise and did some freeway fuel economy testing and found that it got worse. Then it occurred to me that OEM uses IMRC at cruise and Whipple doesn't, so perhaps it only improves fuel economy to go that far retarded if you have the turbulence benefits of IMRC in place. I concluded that everything has to be "just so" in order for those highly-retarded cam timings to show any fuel economy benefits. I'm guessing you're not even prioritizing fuel economy anyway. That being the case, there's not much reason to push them back to 20, 40 at cruise, as it could make economy worse and economy isn't even a priority. I'd probably put them at like 20, 20 or 10, 20 at cruise if it were me, but I have no data to back that up.

 

[deanm11]

Good question. I don't know. First of all, the only reason Ford pushes the cams retarded at cruise is for fuel economy. Retarding the exhaust cam extends the power stroke, while retarding the intake cam requires higher MAP to achieve desired torque, resulting in less pumping losses. It's sets up a pseudo-Atkinson cycle. What I did learn is that I tried running OEM FE cam timing on a Whipple car at cruise and did some freeway fuel economy testing and found that it got worse. Then it occurred to me that OEM uses IMRC at cruise and Whipple doesn't, so perhaps it only improves fuel economy to go that far retarded if you have the turbulence benefits of IMRC in place. I concluded that everything has to be "just so" in order for those highly-retarded cam timings to show any fuel economy benefits. I'm guessing you're not even prioritizing fuel economy anyway. That being the case, there's not much reason to push them back to 20, 40 at cruise, as it could make economy worse and economy isn't even a priority. I'd probably put them at like 20, 20 or 10, 20 at cruise if it were me, but I have no data to back that up.

Cool. Thanks for the explanation. When I get to it, I'll try angles around that for otpimum combination of drive-ability and economy. If I can get optimum economy at 70 on the highway, I'd like it. Fairly secondary goal but I had intended to try it. Maybe an added mapped point for that at a very narrow load range. Economy results are engineering curiosity to me at least. I still don't fully know how my '20 FBO E85 got about 24 highway. On around E72.

 

[tdstuart]

@tdstuart, is it a calibration solution or a hack/shortcut?

A shortcut, makes it so you don't have to tune any of the airflow model. Not that I think its the correct way, but it does work, and is what I did in my tune until I could get a map sensor setup as If I remember right, I didn't have any luck getting the model right without one.

Its what Lund does and what I assume 90% of tuners also do.

 

[deanm11]

Thanks again Mike. I took a lot of what you suggested and made revisions in the attached. I was simply ignorant of the load breakpoints for Optimum Driveability. Eliminated OD and am using FE. I retained all my mapped points, as I have some thought that progressing through those non OP points is a better transition to OP cam angles. Might not matter. I did tweak my OP cam angles so that the interpolation across my 4 OP MPs will allow hitting my OP angles while being exactly on line between two of the points. Going to be a while before I have time to test.

 

[WildHorse]

Yep temps will drop with stock cai and jlt but for some reason creep up with the PMAS. Not sure if it’s the maf location getting hit with a stream of hot air or what

I asked Nick James, MAF positioning, clocking, doesn't matter.
I now have the fender-well kit, IAT are under control now, and drops to ambient when moving.
I don't have the fog light removed, that, IMO will cause more problems. Turbulent air, pressure
spikes, etc. The MAF really doesn't like those situations. I also measured how hot the intake tube
was after some very spirited driving, much cooler than it's surroundings.

As for your situation, only thing I can really think of for your IAT going up is that there must be
something different in the RAD area between your "premium" car, and my "BASE" car, that perhaps
is directing more rad area heat to the fender-well.

 

[deanm11]

Moved my MAF curve up MASSIVELY (20%+) finally deciding there was nothing else that could be majorly wrong in my tune to have desired airmass be WAY above MAF reading.

This was partly based on examining old tune during my second dyno with cams where my desired and actual torque were in line at that time, as well as inferred baro. My MAF was higher at that time... what I moved to today was even beyond this and brought me largely in line. It was partly based on reviewing Mike's old email to me where at one point he was suspicious of my MAF. Not that long ago I did what I thought was right to tune MAF (cyl air aniticipation settings, etc, etc) and that MAF curve was clearly just too low. My trims were on average +5% before this latest tune. I also retested my latest ethanol batch and adjusted Stoich a little.

Tweaking VE just wasn't going to do it. More work to be done but in one fell swoop the inferred baro, load MAF/desired and desired/actual torque is now very close to matching. I had to move wheel torque error limits up with the new time, otherwise it was throwing a wrench. That was from only adjusting the MAF compared to the tune that didn't do that.

 

[deanm11]

Here's the tune and log right before where everything is off. Only difference is MAF curve between the two tunes/logs.

 

[deanm11]

In the improved/today log, if you'd be so helpful and inclined, compare 16.24.50 elapsed and 16.26.19. snapping around 6400rpm. In the initial run up (2nd gear?) to that first point, the trims are circa 5% negative. nearly all the way to 6700. Actually about their worst at the 6412rpm snap there , -7%. Shift out at 8200rpm, stabilize and reach full timing, hit 6400 rpm again, trims are positive! Higher MAF reading by a solid 1lb/hour. A little ram air effect? Almost everything else reads the same. 2 degrees cooler IAT. Any thoughts?

 

[deanm11]

Latest tweaked log and tune. It's running great and the tune seems very solid. The main things that I would want to improve are sometimes a part throttle ease in to near WOT doesn't get PE. Fully going for WOT is never a problem. And I've got some fairly low load, low rpm throttle cases where I've got trims approaching or around -10%. It's not often and everything else is so good. It's probably my crusing/low load MP(18) but I didn't have success changing trims with VE adjustments elsewhere so I'm leaving it for now. I'm hitting near 61 lb/Min MAF at the top with positive/near zero trims.

 

[Pistol_91]

Your 32732 table is strange and may be the reason you're having inconsistencies there.
If I were the ECU trying to figure out when to go into PE I would be confused as in should I make the switch at 80%, 75%, 70%, 65% or 60%? Change the axis values to different RPM ranges or make all the values there the same. It may help.

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