Hi,

Just looking for some clarification regarding what certain rom maps affect, before I start playing around with them. Before I start I will say that I have been searching using google site search but after an hour of searching using various phrases am still none the wiser so if this has already been mentioned in another thread please please please point me in the right direction .

I have also read through the countless bookmarked threads in my favourites. Running GST v3, with only an Evo IX BOV + IC + UICP mods

• Direct Boost section. The Boost Target maps are in PSI and are what the ECU will target as a final value
• Turbo section. WGDC runs the wastegate and (excuse my very noob terminology) once this is fine tuned correctly will mean that the the boost curve is correct (I understand the error correction tables etc (I think))
• Load Boost section. These are the maps that I am unsure of - Boost Target Engine Load - what do these figures relate to? The Load Offset map shows 'zero' so I am guessing these figures are not load based ()

Secondly, assuming that the Load Boost section doesn't complicate stuff I believe that if I wanted to up my boost slightly that I would make minor alterations to the cells in the Boost Target maps, flash n log, then adjust the WGDC values (presumably up) until the boost curve looks smooth? I have read Merlins guide (repeatedly, for months) and read various guides in the forums - just want to be sure of the above before I start teaching myself how to do this...

Thanks in advance

 

Direct boost section and Load boost section tables are the same "data" in the ecu, just scaled in ecuflash differently for our viewing pleasure.
If you run PSI based, which the gst maps do, (1d map under direct boost called Variable for boost control flags the ecu what "mode" boost calcs is in) then dont bother looking at the load boost section, minimize even to help avoid accidently tweaking the wrong section etc.

"target boost error correction" is the table to 0 out to fine tune your reactive WGDC, maybe leave the >3 error psi values alone as -X.X to avoid overboosting while you dial things in.
Start small with the wgdc and work up. keep the general shape inline with the GST ones, nice and smooth!

Yup so you could up the boost target, ecu would get you there but it'd be wavy with all the over/under corrections.
If you first dial in your WGDC to give you the boost curve, then when you turn errorcorection and boost targets back on, the ecu will have a much easier time repeating the nice smooth boost curve.

 

As glenn1234, said... disregard this whole section. We switched from LOAD based targets to PSI based targets, so all the old load-based stuff is now interpreted wholly differently.

Note that the tables in the "Direct Boost" section and the "Load Boost" section are the exact same tables. They are just handled differently by the ECU, depending on the presence/absence of the "Direct Boost" patches.

You'll see this when you change a table value. The same value will magically change in the other section, showing that it's really the exact same table.


Okay. Under "Load Boost", you're looking at "Boost Control Load Offset".

This is the exact same value as the "Direct Boost" value named "Atmospheric Boost".


So... why is it zero?


Because I wrote a ROM patch (RAX Patch: "Atmospheric Boost Baro Compensation") that takes the dynamic reading of barometric pressure, and slots it in neatly as the psi-based offset for the boost target tables.

Before this, everyone had to put "14.7" or "14.5" or "13.1" in that direct boost field, in line with the atmospheric pressure at whatever altitude they hung out at.

When the patch sees that the ROM has a ZERO value here, it activates... and provides the real atmospheric pressure input. The ECU needs this to manage boost targets - so it's always operating off "gauge" pressure, not "absolute" pressure.


Cheers,

Rich


PS. There is another RAX Patch operating, called "IAT Adjusted BWGDC". This one automatically tweaks your BWGDC based on intake air temp. On cold days, you need less WGDC to hit the same boost. On really hot days, you need more. Once you start tuning and logging, you may see a small variation in "map" BWGDC vs. "actual" WGDC. It may be error correction, or it may be RAX Patch.

 

If you haven't seen it already, this could interest you:

https://www.evolutionm.net/forums/09...st-levels.html

Rich

 

Cheers gents - kinda thought that was the case but thought it wouldn't hurt for some sort of confirmation. Now I've had a play with the target figures I see what you mean re altering the Load Boost figures.

Seen it, read it, read some more and will probably read again and again