Mapped Points, OP, Timing, VCT...

[lee82]

I've been looking at my tune file along with several other '15-'17 tunes and I have some questions on mapped points, optimum power, timing advance, and VCT.

In all of the tune files, Mapped Points Configuration shows Mapped Points 13, 26, and OP have zeroes (not used), the rest are 1's.

I see under airflow --> variable camshaft --> Optimum Power there's "enable load" and "enable pedal position" tables. The enable pedal position tables are all 6000 rpm / 89%, but enable load has various load percentages vs the entire rpm range.

I also see under airflow / variable camshaft / OP that there's specific tables for intake and exhaust valve open / close angles.

So here's my questions. At WOT, I use mapped points 7, 21, and 22, depending on the RPM, for timing advance. Does this mean I am also using mapped points 7, 21, and 22 for the intake and exhaust valve opening / closing, or am I using the OP cam timing tables since engine load is over the "enable load" for OP, or do I have to meet both criteria for pedal position AND enable load to use the OP cam timing tables? Or if you are using say mapped point 22 for timing advance, are you stuck with mapped point 22 for cam timing? If you want to use the OP cam timing, do you have to enable mapped point OP as well? Should this even be done?

Last question, is there a book written on strategies / control algorithms? Doing this by trial and error, tweaking numbers, logging, repeat, just to see what tables and variables do what seems backwards.

[Thatwhite5.0]

7 is a blending mapped point. I'd say mapped point 7 through 20 are all blending mapped points. Their main purposes are to transition into Optimum Power which would normally weigh in MPs 21 to 25. These are your more aggressive, power producing valve events are.

The mapped points the weight falls in depend 100% on cam angles. Your IVO could retard from 0* to 5* to 10* to 15*. Your IVO alone would cause blend MP 21 (IVO 0*) MP 20 (IVO 10) and MP 22 (IVO 15).
Your EVC is probably some where in between 10 and 20*, which would cause more weight in MP 21 (EVC 20*) and MP 20 (EVC 15). This is why you see more weight in MP 21 and 22 WOT.

MP 21 is IVO 0, EVC 20
MP 22 is IVO 15, EVC 22 which is high RPM OP angles. At low RPM, the weight will be in MP 25, IVO -20, EVC, 20. Then it will blend from MP 25, to 21, to 22.

Your OP Thresholds need to be met to achieve Optimum Power. You can rescale both of the tables from 6000 to the RPM you desire for your load and throttle thresholds.
The "OP" Mapped Point will not be used. "OP" on an S550 are the IMRC open mapped points and like I said normally run between 20 to 25.

The information is scattered all over the forum, you just have to locate it. The answer to your question could be post number 120 on a 30 page thread. When tuning the coyotes first became supported, "backwards" is all we had and some of us did a lot of work, a lot of trial and error to learn this. A lot of us are still learning and discovering the operation and structure of how the engine and transmission works as one.

[lee82]

7 is a blending mapped point. I'd say mapped point 7 through 20 are all blending mapped points. Their main purposes are to transition into Optimum Power which would normally weigh in MPs 21 to 25. These are your more aggressive, power producing valve events are.

The mapped points the weight falls in depend 100% on cam angles. Your IVO could retard from 0* to 5* to 10* to 15*. Your IVO alone would cause blend MP 21 (IVO 0*) MP 20 (IVO 10) and MP 22 (IVO 15).
Your EVC is probably some where in between 10 and 20*, which would cause more weight in MP 21 (EVC 20*) and MP 20 (EVC 15). This is why you see more weight in MP 21 and 22 WOT.

MP 21 is IVO 0, EVC 20
MP 22 is IVO 15, EVC 22 which is high RPM OP angles. At low RPM, the weight will be in MP 25, IVO -20, EVC, 20. Then it will blend from MP 25, to 21, to 22.

Your OP Thresholds need to be met to achieve Optimum Power. You can rescale both of the tables from 6000 to the RPM you desire for your load and throttle thresholds.
The "OP" Mapped Point will not be used. "OP" on an S550 are the IMRC open mapped points and like I said normally run between 20 to 25.

The information is scattered all over the forum, you just have to locate it. The answer to your question could be post number 120 on a 30 page thread. When tuning the coyotes first became supported, "backwards" is all we had and some of us did a lot of work, a lot of trial and error to learn this. A lot of us are still learning and discovering the operation and structure of how the engine and transmission works as one.

Thanks for the honest response and good information. I can definitely tell you guys have reversed engineered a lot to get where you are, I just need more time to dig around. I just bought and read Lasota's book in one night, hoping it would would explain ALL of the logic, but unfortunately it doesn't. For $125 I guess it does give me some background, but you guys are doing WAY more manipulation and have been giving more in depth responses to lots of questions.

I'll keep on digging and just start doing some reverse engineering myself. I stumbled on some threads late last night that pointed me in a good direction, I just need time a weekend or two on a test track to sort it all out.

[paulsmithsr]

Use stock settings

[veeefour]

There are no gains in VCT angles for OP in stock n/a applications above FACTORY values - period.
I've seen few claiming they managed to "squeeze" more juice by tuning OP angles STOCK but all they do is chasing ghosts by looking at MAF value...
"Look there's a 2lb increase' my angles are better than ford"...no, they are not.

Unless you change intake manifold or cams - different story.

[paulsmithsr]

V is correct

[lee82]

I'm trying to figure out which mapped points are causing the stumble / surge at low rpm & load with IMRC's removed, so I figured I'd try each mapped point individually to see which one(s) are causing issues. Well the first one I tried, Mapped Point 14, is SMOOTH. Zero stumble at low load / rpm, idle is decent, REALLY smooth cruising 30-80 mph. I lost a little part throttle power for sure (which may be due to the IMRCs being locked out), so I set OP enable to 50% load. The car is super predictable and smoother than even with the IMRC's on the gen 2 intake.

So is there any reason to *not* run a single mapped point like 14 or 15 for anything from idle to mild/moderate acceleration and cruising, and only using the TiVCT during OP mode to make sure I get full power? I don't care about emissions and to a large extent efficiency... I'm just thinking longevity of the engine, and negative mechanical effects.

Edit: I'm curious as to what the IVO / EVC angles in the software actually mean in relation to actual angles. I assume the IVO/EVC both cams are at zero advance/retard from their standard position in relation to TDC (whatever that may be, I can't find specs on the Gen 2 coyote cams or how they are set up) when at 0/0. So does 10/10 mean both cams are advanced 10 degrees, or that both the IVO and EVC events happen at +10 degrees to whatever angle they are in relation to TDC, which would be retarded? Judging just by the OP angles and my super basic understanding of how this might affect torque, it would appear that positive numbers are actually retard, and negative angles are advance. So at WOT, you advance the intake cam 15-20 degrees at the mid range, but at the upper rpm range you are retarding the cam 15 degrees. I get that, it helps beef up torque at the mid range AND provide extra horsepower up top. So what does retarding the cams 40-50 degrees at low load do like some mapped points call for? Is this for fuel economy & emissions?

I'm really scratching my head why using just a 0/0 mapped point results in so much smoother operation without IMRC's than using the heavily retarded cam angle tables and/or why we would even use them to begin with.

[decipha]

Its opening the exhaust to get reversion to cause egr for reduced emissions and better economy.

[engineermike]

This is what I?ve determined:

- Startup is 0,0 because that is the neutral unenergized state of the phasers with no oil pressure.
- -20 or -30,0 is idle because it has the least possible overlap, for a smooth idle.
- -30,50 is used at cruise. This represents both cams fully retarded, which delays Evo which in turn extends the expansion stroke and extracts more energy from the exhaust gas and improves fuel economy. Delaying ivc reduces the dynamic compression ratio which forces manifold pressure up and reduces pumping losses. This simulates the atkinson cycle.
- At heavier loads, it starts moving toward the wot region to smooth the transition to OP cam timing.
- In wot midrange, intake cam fully advances to increase dynamic compression and improve torque.
- At wot top-end, intake cam retards to tale advantage of the ram-tuning effect.

[lee82]

This is what I?ve determined:

- Startup is 0,0 because that is the neutral unenergized state of the phasers with no oil pressure.
- -20 or -30,0 is idle because it has the least possible overlap, for a smooth idle.
- -30,50 is used at cruise. This represents both cams fully retarded, which delays Evo which in turn extends the expansion stroke and extracts more energy from the exhaust gas and improves fuel economy. Delaying ivc reduces the dynamic compression ratio which forces manifold pressure up and reduces pumping losses. This simulates the atkinson cycle.
- At heavier loads, it starts moving toward the wot region to smooth the transition to OP cam timing.
- In wot midrange, intake cam fully advances to increase dynamic compression and improve torque.
- At wot top-end, intake cam retards to tale advantage of the ram-tuning effect.

I read some papers last night on this and it's pretty clear. Decipha is in fact correct, and you are correct as well. At the end of the day though, people want to know how to tune their car to operate without the IMRC's and don't care what exactly is happening, just "what are the settings I need to use". But, as a mechanical engineer myself (I had to dust off some knowledge from my automotive engineering courses lol), I want to explain the reasoning behind all of it.

Fords strategy for reducing emissions and improving efficiency at low & part loads is multi-faceted. Retarding the exhaust valve, retarding the intake valve, and use of the IMRC/CMCV system. They all work independently, but also together, and in some cases, you can't have one without the other. The IMRC serves one purpose, creating turbulence at low load, low map, low rpm conditions for better air/fuel mixing and a more efficient combustion. This by itself creates some added efficiency across the board, regardless of cam phasing, and no it doesn't "create more torque", but it does create more torque per unit of fuel/air added because the combustion is more efficient, but only at part load. At WOT, the CMCV doesn't do anything except (hopefully) get out of the way. Retarding the intake cam also creates some efficiency at part load by itself as well, but *only* when sufficient intake valve velocity and turbulence are available. So pre-IMRC/CMCV systems, at low load, low rpm conditions, the intake valve was *not* able to be retarded, because you would lose the ability to mix the fuel with the air sufficiently, so you did it only once you had enough rpm / air velocity (higher rpm / map / load). The emissions reduction gains of retarding the exhaust valve seem to care less about this, so they were able to retard the exhaust valve much earlier in the rpms. So here's the fun part, with IMRC's not only do you get an advantage across the board in the lower rpm / part load efficiency, it allows for earlier retarded intake cam events, which push overall efficiency even further. That said, the IMRC's *must* be closed in order to retard the intake cams at the low load / low rpm condition and still get sufficient air/fuel mixing, so if you don't have them, you cannot expect to retard the cams at the low rpm / load condition and get the same result. In fact, as we all know, you actually get a *poorer* result, with popping, stuttering and less efficiency.

So once we understand this, it's easy rework the strategy in the mapped points and distance tables when the IMRC's are removed. There's probably several ways to do it, but at the end of the day, you need to reduce or eliminate the intake cam retard in the low rpm / low map / low load range, and in some cases possibly dial back the exhaust retard as well. You can leave the cam retard alone at the higher rpms because there's sufficient air velocity already.

IMO, the easiest way to run without IMRC's is killing mapped points 0-13, and then setting all of low rpm / part load cam phasing to 0 or at least reduce the retard phasing by maybe 80% (I'm not sure how much you can get away with, or if there is even any efficiency gain without the IMRC system in place). You could also just kill everything like I did and run one or two mapped points for idle and part load that don't have the aggressive retard phasing.

[lee82]

So running 0/0 without any IMRCs surely makes for a smooth ride but throttle response is kind of blah, most likely due to the less efficient combustion and most likely lower cylinder pressures. The virtual LSA at 0/0 is probably pretty wide, so I wondered what would happen if I tightened it up. So as not to affect the built in advance / retard, I retarded the exhaust cams 5 degrees and advanced the intake cam 5 degrees. Maybe it?s in my head, but this felt much better. I then cranked it to 10/-10 and it got even better. Then at 13/-13 I thought it idled worse (too lopey) and the throttle was actually a bit touchy / too responsive. I settled at 8/-8 evc/ivo. It actually makes the car have a tiny bit of lope to it, nothing crazy, but not the purr of factory angles and IMRCs closed. I noticed though that the exhaust cams don?t phase as consistently as the intake cams at low rpm / idle. Off throttle 1200-1400 rpm or higher it works fine, but 800 rpm no. I guess that?s normal due to lower oil pressure?

[engineermike]

Very interesting; I spent a lot of time on this about a year ago and you’ve filled in a blank for me I hadn’t connected before. I hadn’t realized that delaying ivc would adversely affect turbulence such that you lose efficiency without IMRC.

I noticed that Whipple (no IMRC) was only moving the cams to 30/20 (intake/exhaust) max at cruise. I tried pushing them 40/50 like stock but I carefully measured fuel economy and it only lost efficiency, even though I copied the stock spark tables over as well. I would also note that both the predator and roush (also no IMRC) tunes follow almost identical cam phasing paths as each other and both run 30/30 max at cruise. (I’ve long-surmised that the same person was involved in the roush and predator tunes). I don’t think keeping the intake cam near zero is the answer, but roush and predator certainly thinks 30 is better than 40.

I would also note that I locked mine at 30/0, 40/20, 25/25, and 0/0 (to tune the spark tables) at anything above idle and never noticed any differences SOTP or regarding smoothness. The torque model should handle any losses in torque output for us. I did notice wot differences though.

[Thatwhite5.0]

I'm trying to figure out which mapped points are causing the stumble / surge at low rpm & load with IMRC's removed.

Depending on how you run it. Leaving all MP enabled and trying to run all 25 will cause a nasty blend between spark tables/torque tables and give you bad drivability.

Running 14+, timing is more advanced and torque tables are set pretty high at low loads. MBT needs to be lowered for sure. When your spark tables blend, if your spark advance between 3 blending mapped points, say 14, 15, 16 vary 10 to 15*, you can feel that jolt when you're driving. You may even feel or hear the car switch between these tables as a small surge.
Running 14+ at low load from 1000 to 2000, i usually command IVO 30 evc 10 through the fuel economy distance table.

Cam angles switching between fuel economy and optimal stability can also cause a surge, rather it be the cams themselves, spark advance or the torque tables needing adjust at lower loads.

Also, the cam angles from 0 - 13 and 14-25 are similar, but they are not the same. If you do not change your Mapped points and mapped points distance tables, that will be the cause of your drivability problems. Your cams will be ahead of where they should be. How engineermike explained in #9. Not changing the distance tables will cause the cams to be ahead. Instead of your cam retarding for fuel economy, they're already advancing to get ready for transitioning to OP.

[lee82]

Very interesting; I spent a lot of time on this about a year ago and you’ve filled in a blank for me I hadn’t connected before. I hadn’t realized that delaying ivc would adversely affect turbulence such that you lose efficiency without IMRC.

I noticed that Whipple (no IMRC) was only moving the cams to 30/20 (intake/exhaust) max at cruise. I tried pushing them 40/50 like stock but I carefully measured fuel economy and it only lost efficiency, even though I copied the stock spark tables over as well. I would also note that both the predator and roush (also no IMRC) tunes follow almost identical cam phasing paths as each other and both run 30/30 max at cruise. (I’ve long-surmised that the same person was involved in the roush and predator tunes). I don’t think keeping the intake cam near zero is the answer, but roush and predator certainly thinks 30 is better than 40.

I would also note that I locked mine at 30/0, 40/20, 25/25, and 0/0 (to tune the spark tables) at anything above idle and never noticed any differences SOTP or regarding smoothness. The torque model should handle any losses in torque output for us. I did notice wot differences though.

Interesting. I may need to play with it and see how much if any I can retard the cams and still have good drivability. Maybe 0/0 isn't the best answer, but leaving the stock cam phasing even when only running MP's 14-22 wasn't very good at all either. Maybe there is a happy medium like what Roush is doing with *some* angle change. Less than stock, but more than 0.

Take a look at the Gen 1 (non-imrc) cam phasing. There's very little intake cam retard at low load & low rpm, certainly anything with light acceleration or highway cruising has virtually 0. I'm 99% sure the addition of the IMRC's is the only way you can really pull off the heavily retarded intake valve events at low load & rpm.

[lee82]

Depending on how you run it. Leaving all MP enabled and trying to run all 25 will cause a nasty blend between spark tables/torque tables and give you bad drivability.

Running 14+, timing is more advanced and torque tables are set pretty high at low loads. MBT needs to be lowered for sure. When your spark tables blend, if your spark advance between 3 blending mapped points, say 14, 15, 16 vary 10 to 15*, you can feel that jolt when you're driving. You may even feel or hear the car switch between these tables as a small surge.
Running 14+ at low load from 1000 to 2000, i usually command IVO 30 evc 10 through the fuel economy distance table.

Cam angles switching between fuel economy and optimal stability can also cause a surge, rather it be the cams themselves, spark advance or the torque tables needing adjust at lower loads.

Also, the cam angles from 0 - 13 and 14-25 are similar, but they are not the same. If you do not change your Mapped points and mapped points distance tables, that will be the cause of your drivability problems. Your cams will be ahead of where they should be. How engineermike explained in #9. Not changing the distance tables will cause the cams to be ahead. Instead of your cam retarding for fuel economy, they're already advancing to get ready for transitioning to OP.

The stumbling is definitely happening even in just the pure fuel economy tables with heavily retarded intake/exhaust cam phasing. I've changed mapped points and distance tables and never got it fully straightened out. Changing the cam phasing at part load has been the only answer so far.

[engineermike]

Lee82, I’m pretty sure in the gen1 an IVO of 0 is actually full retard. When the gen2 came out they changed phasers and +30 became full retard. You have to combine the intake IVO in the neutral position (340? in the gen2 iirc) with the IVO number to get the final value.

[engineermike]

Consider this solution….you could very easily use the fuel economy index array to change the commanded points from 3-4-5-6-7 to 12, and from 8-9 to 23. The max retard at cruise would then be 25/25 rather than 40/50, and MP23 would bring it closer to OP to ease the transition.

The only tricky part is that 12 IIRC is an imrc-closed mapped point for which there is no imrc-open equivalent. The solution would be to average all the torque, spark, and SD tables for MP 16 and 20 and use those values for 12. This would be very close to accurate since 12 falls right between 16 and 20. Another solution could be to disable mp12 but command it anyway, which would force the PCM to average the data itself but it will let a dozen of them weigh in.

[Thatwhite5.0]

Lee82, I’m pretty sure in the gen1 an IVO of 0 is actually full retard. When the gen2 came out they changed phasers and +30 became full retard. You have to combine the intake IVO in the neutral position (340? in the gen2 iirc) with the IVO number to get the final value.

I've always looked at it that way, though I don't know gen 2 cam specs. I think they have the same spec but more lift. They're just timed different.
Gen 1 ivo angles -50, -30, 0
Gen 2 ivo angles -20, 0, 30

The stumbling is definitely happening even in just the pure fuel economy tables with heavily retarded intake/exhaust cam phasing. I've changed mapped points and distance tables and never got it fully straightened out. Changing the cam phasing at part load has been the only answer so far.

Running 14+ begins with a big difference. Mapped point 0 is almost irrelevant in the s550s. Mapped point 1 is your idle mapped point with ivo 20 Evc 0. Using MP 15 for idle with ivo 30 Evc 0. With the torque tables set high and timing much more advanced.
Distance # 2 is where the issues you speak of happen when running 14+ with incorrectly assigned fuel economy MP.
MP 2 ivo 30 Evc 0.
MP 16 ivo 40 Evc 20
The cam angles for 16 would be distance 4 using stock tables.. Just one example of the distances getting ahead of where they should be. These angles would be too retarded for the load, rpm and driving conditions they would be in.

[Thatwhite5.0]

Lee, turn on your misfire counter and see if what you're feeling is misfires.

[lee82]

Lee82, I’m pretty sure in the gen1 an IVO of 0 is actually full retard. When the gen2 came out they changed phasers and +30 became full retard. You have to combine the intake IVO in the neutral position (340? in the gen2 iirc) with the IVO number to get the final value.

I didn't catch that, but I see it now. Thanks!