Hi
I have a problem with my car that I believe can be sorted out with changes to the ecu. It is a boost control issue and causes the car to surge under moderate acceleration, with the boost fluctuating up and down as it accelerates. This is most pronounced between 3000 and 4000rpm in 5th and 6th gears. Car is a 2001 JDM STI with AF481-7546 ecu. Apparently it is a common problem when a fully decatted exhaust has been fitted, which mine has.
Before I start making any changes I have been trying to understand what's happening with the various maps and I have been looking at the rom from the car as well as other roms from other STIs from the JDM and EU markets. I have noticed that some roms have '#14 - Initial Wastegate Duty - A' and '#14 - Max. Wastegate Duty - A' maps but mine shows '#05 - Max.Wastegate Duty (A-Auto)' and '#05 - Max.Wastegate Duty (B-Manual)'.
I guess this is a map for an auto car and a map for a manual car, although the maps are identical, so I understand that. However, there is no initial wastegate duty map showing for my car either in Auto or Manual.
I used the latest version of xmlwrite integrated with ecuedit to produce the list of maps but I'm wondering if there is a way I can check everything has been identified correctly.
Going on from this, the Max Wastegate Duty map for my car is very different to those from other cars where there is an Initial Wastegate Duty map and a Max Wastegate Duty Map. The Initial and Max maps seem a lot flatter and smoother with the duty being a lot more constant through the rpm and load ranges. The throttle is shown as 16 bit on mine but 8 bit on the others.
I have compared the maps from my car with those from an EU STI. This is a very similar car, but produces less output in stock form than the JDM equivalent because it is tuned for EU emissions levels and fuel which is lower octane. I also compared it with the rom from the S202 and this also has Initial and Max maps which are quite flat.
So I have some questions,
firstly am I seeing all the maps correctly for my rom ?
second, if this is correct why is there only one wastegate duty map and why is it different to many other STI roms of similar spec / year ?
third, does it make any difference if the throttle is shown as 16 bit on mine but 8 bit on others ?
and finally, can anyone give me any guidance on making changes to the wastegate duty maps ?
I have attached a word document showing the lists of maps from the 3 cars and their wastegate duty maps so you can see what I mean. My rom is in the JDM STI 2001-2003 section. There is another rom from a 2003 car and this has identical maps and also displays the same, ie only one wastegate duty map.
If anyone can answer my queries and help me resolve the boost issue I'd be most grateful.
Many thanks