Boost tuning - need help understanding factors

[caramall2]

I've checked out Merchgod's info on Turbo Dynamics Integral and Proportionate, and one on NASIOC, but still fuzzy and not sure what the map parameters mean.

http://www.romraider.com/forum/topic1814.html

http://forums.nasioc.com/forums/showthread.php?t=1433698

(Also read Cobb's article on the boost system and info in ST guide on boost.)

Feel free to point me to a post, etc.

 

Basic Forumula:

 

x = WGDC initial (post compensat) + TD prop + TD integral/cumulative

 

 

WGDC low: What it starts at to hit target boost (ECU can go below this if necessary, right?).

 

WGDC high: Max WGDC system will allow, no matter what other inputs there are, right?

 

TD Coarse Gain High:

-- Adjusts if boost too low and needs to increase?

-- Does it affect proportional or integral?

-- Map: What do values mean (not sure on top row)?

Top row: -240 to 0

Bottom row: -5% to 0%

 

TD Coarse Gain Low:

-- Adjusts if boost too high and needs to decrease?

-- Does it affect proportional or integral?

-- Map: What do values mean (not sure on top row)?

Top row: 0 to 240

Bottom row: 0 to 9%

 

Turbo Dynamics Fine:

-- Fine tunes boost up or down

-- Does it affect proportional or integral?

-- Map: What do values mean (not sure on top row)?

Top row: -150 to 150

Bottom row: -5% to 9%

 

 

Guessing that TD Coarse affects TD integral, and TD Fine affects TD proportional.

 

Some of my logs are showing at a point in time....

WGDC = 85 (about max I allow in the table at that point),

TD integral = 15, and

TD proportional = 3 (or sometimes negative).

 

Does ECU think something like....target is 18, WGDC low is 50, he's only at 15 psi, I'll add integral of 5, nope not enough, ok, 10 (meanwhile proportional is also making small tweeks), now TD proportional is taking away boost, better lower integral, etc, etc. Again, just not sure how it works.

 

I just got through getting a basic understanding ignition timing....now I need to learn the boost side.

[boostsr20]

In for learning experience.

[Legacy_GT_Pilot]

Here's a link to a thread that was discussed a little while back that has a lot of good info in it. It should answer much of your questions.

 

http://legacygt.com/forums/showthread.php?t=72638&highlight=PID

[caramall2]

Thanks! Page 3 on that post is jackpot...bublatterbeast's info that mickey and LBGT helped on. Now I have to read and re-read it.

http://legacygt.com/forums/showthread.php?t=72638&highlight=PID&page=3

 

It is also nice to know in theory how proportional and integral work.