What does the Proportional Max table do?

[npaz]

What exactly does the Desired Boost PID / Proportional Max table do?

I can't find a simple or clear answer to this!

[T-Man]

What exactly does the Desired Boost PID / Proportional Max table do?

I can't find a simple or clear answer to this!

https://www.hptuners.com/forum/showt...l=1#post346949

Edit - Read this one too

https://www.hptuners.com/forum/showt...l=1#post249813

[npaz]

Hi T-Man,

I found and read through both of those already. Pretty good explanations on the Gains tables, not so much on the Prop Max. It's still not clear to me.

"Prop max is a limiting table. It should have no affect if it were only a limiting table, but this doesn't seem to be the case. It appears to be used as reference elsewhere with minor effects as you raise it. I set it to 327% to eliminate any possible interference or extraneous effects."

That's about the clearest answer I found, which still isn't very clear at all. I don't want to eliminate it, I would like to know what it does. Max is 120 kPa or 17.4 psi. Is it 0 to 100 in percent? Is it the limiting table for the Prop Gain S/S setting only? What "minor effects" does it cause?

[ECaulk]

As stated in the thread T-Man linked it's boost ramp. And like Codenamebildoe states there are multiple tables interconnected so you can start adjusting some of the tables and test things out. Just be ready to have the car run funky and be ready to push the clutch in quickly if something to crazy occurs

[cobaltssoverbooster]

you have to understand the PID control systems in order to understand prop max. its a table that limits maximum allowed change based on the proportional gain. technically it is a limiting table but if you don't understand proportional control then you wont fully understand it.

if you don't know anything about PID systems read through the Wiki description for it. that will give you a good start.

[npaz]

I have a grasp of the PID system, but can someone give me a simple cause and effect explanation for the Proportional Max table? I understand multiple tables are being influenced here, but someone must have played with Prop Max and come up with some general conclusions on it's range of influence and impact.

In other words if you raise the values, X happens. Lower values, Y happens. I did try raising the 100/120 columns to 95 to see if it was acting as a limiting table. It didn't really change the boost levels, but felt like it slowed down and mellowing boost increase, seemly acting as an inverse.


Also...Why a range 0-120 kPa? Max on the stock table is 95. Is the range 0-100?

Thanks!

[cobaltssoverbooster]

proportional max is the limiting factor to the proportional gain table as the name implies.

proportional table being the adjusting factors for the error between actual and target boost. This is the first step in a 3 leg control system.

[MikeM173]

You are missing some key info on the PID Tables. There is a point where the system starts over. You?ll notice the max on the Prop Table is higher than what I use in my starter file. The system will actually max out and then start over. When HPT unlocks stuff, they aren?t concerned with how each table works, but rather getting us the tables that we need (so they are concerned to some degree). There is no point for them to try and limit us in the table based on how it works, that is for us to figure out. That?s why in my starter file I don?t use the 327 or whatever the max is in the Prop Max table. Bill does, but me and Bill do things slightly different.