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      01-16-2013, 10:16 PM   #1

Drives: BMW
Join Date: Aug 2012
Location: Arizona Bay

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Correcting Boost overshoots in ATR

Me and rader1 have been working together on a simplified walkthrough of ATR describing how to fix common issues or how to dial in boost/timing curves. He posted a short and general DIY the other day and i thought i'd share it here for you guys that are seeing boost overshoots in your logs. Expect a much more detailed walkthrough that covers this and more subjects in the next couple weeks.

Originally Posted by rader1 View Post
Add "Boost setpoint factor" and "MAF requested(WGDC)" to your datalog list. Then grab a couple more logs and where the boost overshoots are occuring in relation to the above logging channels pull a little WGDC out. The general consensus is to make reductions 10% at a time so as not to pull too much out.

An important thing to note is to be sure ATR is setup to display the MAF REQ(WGDC) in (GS) rather than (KG/m)

(Keep in mind the following is all just for example)
So, for example, if your overshoots are happening at:
Boost setpoint factor= 2.1

Then you open ATR, go to the WGDC base table and find the cells that correlate best.

Then pull some DC out

Then, save the map. Transfer to the AP and relog and see how it looks.
Give it a few pulls after flashing so that the logs have calmed down. You don't want to end up chasing your tail over an issue that may not really be there.

Also, when using this method it's possible that you may run into boost oscillations. If that happens it means you're getting close to where you wan't to be.
One thing I would like to add to this is that if you are consistently UNDER boost target(usually it will be in the higher RPMs) you can ADD some DC into the base table using the same process until you hit target.
"I'm not surprised you get along well with all the other neighbours. If you put fifty children with Down's syndrome in a room there is going to be a lot of hugging." David Thorne