I just noticed my min temp for full boost control is 85 degrees celcius (stock setting). That is 185 in fahrenheit. Does the ecu really use this? My logs show below 185 a lot but still seems like full boost control is working.

 

just lower it and be happy

 

I have reason to believe this is actually WGDC before full engine temp but would need one of the ROM gurus here to check into it.

 

Here's some data for your theory.
Logged 176 temps the other day.
Logged WGDC numbers were equal to my MWGDC table 1. (numbers in the 60s)
Tables 2, 3, and 4 all have numbers below 50.

This is why I thought the ECU doesn't use this variable but it must - just how.

 

Actually let me rephrase that.

I have reason to believe this should be minimum WGDC before full engine temp.

Remember stock WGDC is 100% in all 16 cells.

I tried switching it to WGDC in the def but it went to 0% so I think the whole def is wrong.

 

It also affects the time before the car goes to mapped fueling. Otherwise it runs a certain percentage richer until it has reached it. I have also noticed as Bryan pointed out that the ECU (if still controlling boost) cuts boost until that min temp has been reached. I have enough self control to not get crazy when the car is "cold" but I have mine set at 65-70* just so its not running way rich when I first start driving in the morning.

 

Hey Guys,

razorlab PMed me about this last night. It looks to me like the definition in ECUFlash is completely wrong. In the ROM code, this value appears to be a threshold test on the WGDC read from the BWGDC tables. The stock value is 62.5% WGDC. If the WGDC read from the BWGDC table is below this threshold value, then the ECU chooses between the value from the table or some other value that it calculates in another subroutine. It doesn't appear to have anything to do with temperature.

There is however a table that does control WGDC vs temperature. I found it a while ago but never published it. There is also another table that controls the maximum WGDC "correction" vs TPS. Screenshots will be attached shortly.

 

Thanks for the confirmation mrfred.

I really wish I knew this disassembly stuff better as I have had two good 'hunches' so far that turned out to be true. One being that the boost follows a different load than normal 2byte load, which you later found out and now this.

Maybe it's time I hire a guru... haha

 

I've noticed that when the car is cold it never logs 100% TPS. And no, I don't romp on my car when it's cold ... I did it specifically to see if that value actually changed anything.

Mrfred's post seems to be much more informative though ...

 

Cool. Thanks, MrFred.
So based on your table you have if my temp is 70 degrees or more then the ECU will use 100% of the value that's in the BWGDC table? That explains why I was running my target WGDC.

 

Did you mean maximum?

 

I think the bigger question you should ask yourself is why are you wanting full boost on a cold engine

 

I wonder what the side effect of lowering that number is.

 

I dont think anyone is doing this for full boost, but rather full fuel control. I really hope no one is doing it for full boost control, though 85* C means the car is never at operating temp under normal driving conditions...though thats not what it represents apparently.