Caddy ats looking to other Eco guys for help with meth tune

I didn't understand the nature of the car on spikes I guess you can say as to understand the zeroed out areas are areas of no control so causing that spike. Now to understand a table completely is essential to being able to make correct adjustments. So looking at my prop table or any other it will have an obvious value of rpm and then to me at least not obvious value pressure delta starting at a negative and increasing to a positive of 4.4 I believe not in front of me at moment. So how to relate the pressure delta to kpa or boost value is my oy way to understand it as I have no clue how pressure delta is related at all. A lot of tables are using this and must be very important and probably some calculation on barometer and kpa to come up with the pressure delta? This is where the greater knowledge of your guys really comes in handy. I have a lot of tables that once I figure this out as even my dc waste gate table uses this on left column so knowing this will help me a ton on so much and guess should have asked this much sooner but thought I had it figured out until some settings didn't fall in line to my logs on kpa so threw that math out the window.

Delta = change

What's the rate of change on a scale if I put one ounce of coins on it per second versus putting 20lb per second on it? That's your rate of change. Higher delta is higher rate of change.

If you slowly reach for my face I only have to move slowly to push your hand away. If you try to slap me fast I have to react much more aggressively to block it.

Same with accelerating to 60mph. If I'm approaching 60mph by accelerating 1mph per second, I can gently lift off gas to hit 60. If I'm accelerating at 20mph gained every second I'm going to have to slam on the brakes to hit 60 exactly.

Same concept with pressure delta. ECU doesn't need to overly damp the system on small pressure changes (from 4 to 5 psi, for ex). So, it allows you to put smaller numbers for less damping. Bigger changes in delta require more system damping to prevent overshoot.

So changing the pressure delta factor table increases the rate of change so knowing that tables like base dc prop gain intergeral and derivative to name a few that use that value in the left column still doesn't give a way to convert to a known value like psi or kpa so to know the scale of that table. For instance base dc rpm vrs pressure ratio everyone knows rpm the value of it and noting will change its rate and you can read it on a gauge easily. Now pressure ratio there is nothing to compare it to so to know the value of the number. We now know the pressure delta factor can make changes to that value but there isn't a gauge that reads pressure delta so what's the conversion from that to say psi or kpa so to know how to adjust those tables properly with out guessing?

And while on questions that are killing me with my tune. When I log I see what the computer wants to see in a few values say commanded afr or boost desired if the program over or under shoots afr the computer compensates a percent before setting a code through ltft or stft and it doesn't really hurt performance. Now if the actual map (kpa) over shoots the desired boost (kpa) it pisses it all off and either closes the throttle or pulls timing maybe even both. This hurts performance bad. Can kill a good pull down a long straight or just pulling into traffic in a hurry when need the car to go. It becomes dangerous in a sence as you expect the car to do something and one time it might pull like hell and get going and another it lays flat because of some change the programs might see that time. So to set that value high and out of the way would be such a plus if that is even possible. So how does the computer come up with this value of desired? A combination of tables? Or something specific I am just looking over? The two last posts are pretty important for someone like myself learing this as it is like not knowing the x and y of a shape when it is a simple triangle as you only know z and trying to figure out the whole damn measurement of that triangle. You can guess forever and might get lucky and hit it but to know the values then do the math and get your answers. Surprised bill is the only one answering this stuff as someone like my self learing a new system this is so valuable and know not everyone gets all this and would have thought a lot more would have chimed in on these couple posts I have put up.

And looking at my dc boost table maybe I just answered part of the question as that is what is setting where boost should be calling for a desired figure? So why the over shoot then if that is it? That is if that is correct. I have had it speed up so fast it makes the car slam or buck hard so this table is finicky for sure. I guess where the other three boost tables prop and so on help adjust the speeds or way the dc table can act ?

Going one post at a time. More punctuation, please. Really hard to read.

On pressure delta, you're way overanalyzing it. It's a simple concept. Regardless, we have made threads on what the tables do. Derivative controls overshoot, for ex. Change the zeroed columns or the whole table to 4.0 and do a pull. See what happens. Adjust down accordingly until you get boost ramp overshoot just right.

You're not writing a thesis on this, just learning to use the tables to get the engine to do what you want safely.

For desired versus actual, understanding how the PID's control boost will eliminate the need to make desired so stupid high that it's out of reach of actual. That's putting a bandaid on a cut to fix a hole in your spleen.

The reason you don't want to do that is because the desired is a reference probably for several dozen or hundreds of other tables. You're severely skewing the whole ecu modifying it too greatly. Desired should be set above your actual goal. Then, read up and learn to adjust the PID's and other tables to avoid superceding that limit.

For the third post idk. Haven't played with ats yet to know exactly what it's doing.

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Originally Posted by codename Bil Doe

For desired versus actual, understanding how the PID's control boost will eliminate the need to make desired so stupid high that it's out of reach of actual. That's putting a bandaid on a cut to fix a hole in your spleen.

The reason you don't want to do that is because the desired is a reference probably for several dozen or hundreds of other tables. You're severely skewing the whole ecu modifying it too greatly. Desired should be set above your actual goal. Then, read up and learn to adjust the PID's and other tables to avoid superceding that limit.

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How do you control what desired boost is? The only thing I've found that effects it is the peak torque and DD. Is there another that is useful? Mine seems to be stuck around 220 kpa. (1.4L Cruze, but the theory should be the same)

I got mine to move up or at least kept them from crossing paths by adjusting the pressure delta factor higher. Know the cruise is damn near if not the same as ats where LNF is not even in the same game as ats now that I have looked at one. The LNF is a piece of cake after dealing with this ats. There is around 10% the amount of tables and most have a load vrs value is easy to make sense of any adjustment. I wish the ats and cruise were that easy and probably why no one answers these threads but bill. I have a good grasp on this now by accident of course but know more now why it is doing certain things and how to correct most of it. Playing around over the weekend I really hit on some stuff and now am loging over 100 more lbs tq on a much flatter curve with only a couple small adjustments. It is tempting to try too many adjustments at one time and learned the hard way by fighting this car that sometimes just one adjustment and then try it is the way to go as u can cancel out what you trying to achieve by attacking too many tables at once.