3.5 EcoBoost Advice?

[Bugasu]

To me, it seems as if getting the Desired TIP (Throttle Inlet Pressure) up is what you're after when tuning the boost level here, then changing some of the limiters on the turbo/wastegate settings as not to go past them. I'm going to poke at some parameters some more and see if I can get the desired TIP up at this point.

Precisely. The basic workflow for the ECU is:
Torque Desired -> Load Desired -> Airflow Desired -> MAP Desired -> TIP Desired -> Turbine Conditions needed (Mass fraction etc) -> Final WG Request.

You need to work your way through each stage. Torque Desired to Load Desired through the Torque to Load tables, Load to Airflow is a basic calculation, Airflow to MAP is through the VE equations, MAP to TIP is a few tables which might not be available on your strategy (essentially just to have delta pressure over the throttle for better transient performance), turbine conditions is fancy math you dont really have control over, and you obviously have the wastegate maps.

The goal then is to get TIP Desired up by getting your Torque Desired/Load Desired up, and then to tune your wastegate system until you can get TIP Actual to match TIP Desired in as many conditions as you can. If TIP Actual > TIP Desired (and thereby MAP Actual > MAP Desired), the ECU closes the throttle to control the airflow delivered. You're basically going the right direction with what you want to do.

[96gt4.6]

Precisely. The basic workflow for the ECU is:
Torque Desired -> Load Desired -> Airflow Desired -> MAP Desired -> TIP Desired -> Turbine Conditions needed (Mass fraction etc) -> Final WG Request.

You need to work your way through each stage. Torque Desired to Load Desired through the Torque to Load tables, Load to Airflow is a basic calculation, Airflow to MAP is through the VE equations, MAP to TIP is a few tables which might not be available on your strategy (essentially just to have delta pressure over the throttle for better transient performance), turbine conditions is fancy math you dont really have control over, and you obviously have the wastegate maps.

The goal then is to get TIP Desired up by getting your Torque Desired/Load Desired up, and then to tune your wastegate system until you can get TIP Actual to match TIP Desired in as many conditions as you can. If TIP Actual > TIP Desired (and thereby MAP Actual > MAP Desired), the ECU closes the throttle to control the airflow delivered. You're basically going the right direction with what you want to do.

Thank you! I had the right logic, just needed it laid out as to how the computer gets to the calculation of the TIP desired. I knew that if I can get the TIP desired up, then I would simply have to move some of the boost and wastegate limiters up as i'd be approaching them with the new settings. Thank you for verifying my theory. I'll poke at some of the tables and see where I end up. I have deduced a lot of where I need to start by comparing the '11-14 Eco Boost tunes from an SCT vs. Stock tune. It looks like the Torque inverse tables, amongst others, are the main starting point. Now, i'm trying to develop a handle on how much to modify the values to get where I want to be, it will take a little bit of poking.....and the 3 minute write time sure makes for some good seat time! haha.

On my 2012 I upped the turbo protection limiting numbers a bit and started playing with the wastegate duty cycle to get boost up but at this point im not able to hold boost that well so im starting to adjust the proportional and integral gains to flatten the curve. I'm guessig that the wastegate solenoid runs on a PI loop to adjust how the selenoid is cycled but im not completely sure if it can be tuned like your typical closed loop system.

This was my first thought as well, but knowing that the computer will always shoot desired TIP, it would only work it's way back down as you're having. Sounds like the key is as described by Bugasu, we have to follow the computers calculated logic path to get the TIP requested value up.

Very good guys, let's keep it going!

[Eric@HPTuners]

Guys if there is some specific variable you would like to be able to log, I can probably find it and add it to our scanner.

[wbt]

Guys if there is some specific variable you would like to be able to log, I can probably find it and add it to our scanner.

IMO mapped points would be most valuable.

[96gt4.6]

Guys if there is some specific variable you would like to be able to log, I can probably find it and add it to our scanner.

Thank you for being so helpful on everything Eric! As soon as I decipher what i'm actually needing i'll certainly be asking for anything that I might not have.

So, we've deduced that to get a higher commanded TIP (boost pressure), we need to command more torque, which in turn we need to command more load.

I'm working on currently trying to decipher what load the stock tune is commanding, but am unsure on which PID indicates this:



I'm ASSUMING calculated engine load, as the calculated engine load close to 1.0 in this log, corresponds to the commanded torque value in the scanner, which corresponds to the torque value listed in this table around that load on the LH Axis, give/take:




It appears that the stock load v. Torque table is filled out with values that will be more than I'm going to ask for at over 500+ ft/lb on the 1.8 load cell, therefore to me it would seem as if all I need to do is get the requested load up more and that in turn should request more torque which would in turn request more TIP:



What i'm struggling to grasp is how to request more load, if I could get into these cells, the torque values are greater which should up the boost:



Here is something that throws me off though......this table is taken from an aftermarket tune on a 2012 F150 3.5 EB. I compared it to a stock file from the same year of truck, and the aftermarket tune has the load v. torque values all lowered.......i'm still trying to decipher what the logic in this is. Is it perhaps a way to fool the system to get more boost?



Stock table on the same truck:



Again, thanks for the help so far! I appreciate the opportunity to learn and the willingness of those whom have helped out!

[Bugasu]

Going the wrong way
Your throttle requested torque goes through the torque to load to be come the requested load.
Thus, when you see them lower the TTL requirements, essentially thats raising the load request for a given torque. I.e. before 400 Tq Requested would be 1.3 load, now its 1.6 load.

The load to torque tables are the inverse, meant to match it up I believe for actual torque measurement at the end. I don't believe they play a direct role in the request.

So what they're doing is keeping your throttle table torques within the normal range for example, and then by lowering the TTL tables (and raising the LTT tables), you effectively are requesting the higher load.
Don't forget that as you raise these loads, you will run into other limiters. A good way to see which one you're currently hitting is Airflow Limit Source if its available to you. This will give you a clue which table you need to use to shape your desired load curve.

Also, the only load you probably want to monitor is "Air Load". Calculated Engine Load is basically your current air load divided by the maximum air load for your cam pair. These tables I don't know if they exist from any of the maps I've been on, but they're not that important to line up anyways. Absolute Load is a better reading, closer to the one you see, but it doesn't update at the same rate as Air Load I believe. Air Load is also based on in-cylinder actual airmass, where as Absolute is throttle plate flow (which will be more because some air blows through the cylinders in some situations).

[96gt4.6]

Ooook, now that makes sense and I see the flow path for this, THANK YOU!

So, the question I have now, instead of scaling the requested torque to load table down to get a higher load, why not just request more torque via the driver demand tables in the first place? Wouldn't that be easier? (just trying to understand the thought process and logic path to scaling the tables vs. just asking for more TQ, still learning!).

And yes, once these are scaled, there are a few tables that need to be modified I see that will clip the power.

Again, thank you for taking time to explain this, it helps immensely as the whole Torque based tuning is something i'm still learning, and knowing the logic process the ECU uses and what the tables are referenced for helps a lot.

[Bugasu]

Ooook, now that makes sense and I see the flow path for this, THANK YOU!

So, the question I have now, instead of scaling the requested torque to load table down to get a higher load, why not just request more torque via the driver demand tables in the first place? Wouldn't that be easier? (just trying to understand the thought process and logic path to scaling the tables vs. just asking for more TQ, still learning!).

And yes, once these are scaled, there are a few tables that need to be modified I see that will clip the power.

Again, thank you for taking time to explain this, it helps immensely as the whole Torque based tuning is something i'm still learning, and knowing the logic process the ECU uses and what the tables are referenced for helps a lot.

This is a valid option, but I think the reason is probably because of torque limits that we may not have access to. I have done this for some vehicles without any problems, and then others I'd always end up hitting a cap I didn't have access to. You also have the issue that without a load bearing engine dyno and a lot of time, you'll not be able to really dial in the table to its true values anyways unfortunately, if that matters to you.

I also forgot to add, if you click on the Axis Label, you can modify the axis itself. I was unclear if you were saying you couldn't modify them, because you should be able to

[96gt4.6]

This is a valid option, but I think the reason is probably because of torque limits that we may not have access to. I have done this for some vehicles without any problems, and then others I'd always end up hitting a cap I didn't have access to. You also have the issue that without a load bearing engine dyno and a lot of time, you'll not be able to really dial in the table to its true values anyways unfortunately, if that matters to you.

I also forgot to add, if you click on the Axis Label, you can modify the axis itself. I was unclear if you were saying you couldn't modify them, because you should be able to

Got it. And yes, I had seen you can modify the axis table to add more load/TQ as necessary, but as you stated there is no way to populate the table without a dyno or simply guessing, which can yield driveability issues and what not.

My stock tables appear to have about 3-4 load cells above where it's at now and the tables are populated by the OE calibration, so I believe I should be OK by asking for more TQ from the driver demand table. Of course i'll go in and cap the ignition timing 4 or 5 degrees lower as i'm not sure how much more boost this will theoretically add initially.

Eric, are there any tables in the tune as was being described earlier that relate Torque or Load to Desired TIP pressure? This would be nice as we could see what's going to be requested by requesting more Torque/Load beforehand.

Excellent info guys!

[Bugasu]

Got it. And yes, I had seen you can modify the axis table to add more load/TQ as necessary, but as you stated there is no way to populate the table without a dyno or simply guessing, which can yield driveability issues and what not.

My stock tables appear to have about 3-4 load cells above where it's at now and the tables are populated by the OE calibration, so I believe I should be OK by asking for more TQ from the driver demand table. Of course i'll go in and cap the ignition timing 4 or 5 degrees lower as i'm not sure how much more boost this will theoretically add initially.

Eric, are there any tables in the tune as was being described earlier that relate Torque or Load to Desired TIP pressure? This would be nice as we could see what's going to be requested by requesting more Torque/Load beforehand.

Excellent info guys!

The tables you seek are the VE tables
Load Desired is converted to Airflow Desired via math, and this airflow is further limited and then pumped

Remember, 1.00 Load represents that the cylinder has as much air as would be expected at 100% VE under Ford's ideal operating conditions (29.92 in.Hg, 100* manifold charge temperature, 200* engine coolant temperature). This value depends obviously on the displacement of the cylinders. You can find it here:


So, if you multiply your current load by this value, you get the current aircharge per cylinder being inducted. I.e. you get a lb-mass / induction event.

You then need to convert that to lbm/min to get the airflow.
So, we have to calculate how many induction events we have per minute to finish it out.

This is straight forward enough: Induction Events per Minute = Number of revolutions per minute * number of cylinders inducting per revolution (2 for 4 cyl, 3 for 6 cyl, 4 for 8 cyl etc).
So, to add it all up then:

Airflow = Load * Standard Aircharge * RPM * Cylinders Inducting Per-Revolution

So with your example posted before with Air Load of 1.62:
Airflow = 1.62 * 0.00157 * 4151 * 3 = 31.673 lb/min

So once the Desired Load is found, it calculates the Desired Airflow via this means, limits it, and then this airflow is put through the VE equations to get a desired MAP essentially. There's actually quite a bit more to it than that, but it boils down to that.

[96gt4.6]

Excellent! Thank you!!

I'm starting to poke around at this point, working my way through what we have been discussing, but I have already encountered an issue I can't seem to grasp.

I've begun to play with the Driver Demand table under Engine>Airflow>Electronic Throttle.

First up, I wanted to see if I could request less torque under high accelerator pedal input, so that I could check to see if the flow path/changes agree with what I had come to understand. However, the results were not as expected at all. With the way the table is set up, seen here:



I should be seeing less torque at wide open throttle, however, the results were the exact opposite, and at part/low throttle. I was getting nearly 3/4 throttle at 25% accelerator pedal input, but I had not made any changes to that part of the table. As seen here, the TP was much higher than the APP:



What am I missing here? Looking at the way the table is set up, I should be getting less engine power with higher throttle, correct?

[dlgransion]

which mode were you in? Normal, tow, or sport?

[96gt4.6]

which mode were you in? Normal, tow, or sport?

Initially I was in Normal mode, then when I had seen no changes I copied the same values to both Sport and Wet/Snow modes, with the same result.

[96gt4.6]

Could this perhaps be a '15 forward thing only? Or, perhaps the reason that on the '11-14 modified tune I've shown, they never mess with the Driver Demand table. I'm simply curious as to why it affected the off-idle/part throttle table so much, nothing was changed on that end of the table whatsoever, and commanded torque under WOT didn't move from 4xx Ft/lb even with the tables set so low in that range.

Trying to get a grasp on this before I proceed, there is no point if I can't understand where values are being drawn from in poking around not knowing the results.

[Japeatr]

any issues pasting sport mode pedal response tables into normal ONLY?

[Japeatr]

on my 13' im not finding the pedal ratio tables for each mode, can you elaborate?

[96gt4.6]

any issues pasting sport mode pedal response tables into normal ONLY?

Not presently, it seems to work fine.

on my 13' im not finding the pedal ratio tables for each mode, can you elaborate?

To my knowledge, only '15 and up have these tables accessible:

[Japeatr]

my '13 does not have that table

[96gt4.6]

my '13 does not have that table

I had noticed that as well when downloading and comparing tunes for the '11-14 Eco's. It must be a '15 forward only deal.

Well, I had a chance to experiment with the pickup this weekend, and I still haven't figured out what i'm looking for on getting the commanded TIP up.

I moved the Load/TQ values down, moved the Torque to Load cells up in the last few rows, and raised some of the limiters on the turbo protection as far as outlet pressure a couple of lbs just in case they were limiting me. Also raised max load LSPI to 1.8 across the board, and max commanded tq to 460 with no avail.

I did however enjoy taking the combustion stability limits up, that seemed to make a great difference on the power braking of the truck, it holds boost much better when two footing with those limits raised.

Still can't get the hang of commanding more boost throughout a gear though. I'll keep poking one table at a time and monitor changes, hopefully i'll start getting where I want to be.

Also, i'm also down for a little help from tuners here as far as a little PayPal action goes if someone is willing to nudge me in the right direction. Get with me via PM if that's the case. And, as usual, any input/advice is much appreciated! It appears the '15 and newer pickups might command things a bit differently.

[caniggia]

My guess may be, that this turbo is maxed from factory, could it be? Can you put there MBC for test?