Good getting started summary to tuning:

Disclaimer first: I'm just getting into tuning myself. Don't trust this until it's been verified by someone with more experience. I think it would be useful for the FAQ though (if/when it's correct).

First, make sure the ECU knows what it's attached to:

MAF Sensor Scaling - It's a good idea to get this dialed in before you start. And definitely revise this if you change your intake anywhere near the MAF sensor. It tells the ECU how to interpret the MAF sensor voltage to know much air is going into the engine. The learning view tool and the RomRaider logger's MAF scaling tab will help dial it in. There's also a spreadsheet in a sticky thread in the tuning forum.

Injector Latency and Injector Flow Scaling - change these if you change your fuel injectors. They tell the ECU how long it takes for an injector to fully open, and how much fuel the injector flows while it's open. Together they allow the ECU to squirt just the right amount of fuel. RomRaider's logger has an injector scaling tab which is helpful. You can also tune these by watching the fuel trims shown in the learning view tool.

Then, the "real" tuning. The main things are fueling, boost, and timing. All of these will induce knock if you ask for too much power, and they interact, so after making changes you should log to ensure that you haven't overdone it. (Knock is a leading cause of death for high-performance engines.)

Adjust the Primary Open Loop Fueling table to get the right AFRs. You'll need a wideband O2 sensor to verify your changes here, since the stock O2 sensor is not accurate under boost. You may want/need to adjust the MAF and/or injector tables as well if you car isn't hitting the desired AFRs.

Enter your boost targets in the Target Boost table. You will likely need to adjust the Initial Wastegate Duty and Max Wastegate Duty tables to get the engine to hit your targets without overboosting. Also consider the various Turbo Dynamics tables to help hit your boost targets.

Use the Base Timing and Timing Advance (Maximum) tables to adjust ignition timing for best power, without detonation.

Opinions vary about the best order in which to adjust fuel, boost, and timing. There isn't necessarily a best way to approach this, since the adjustments need to be iterative and you need to experiment with different tradeoffs to determine the which compromise across all three makes the most power without inducing detonation (more boost with less timing / leaner AFRs with less boost / more timing with richer AFRs, etc).

Miscellaneous:

Some people extend the knock detection range all the way up to redline (Feedback Correction Range, Rough Correction Range). Some say that the sensor isn't very accurate outside the stock range, I can't say who is right.

Some people zero out the Closed Loop / Open Loop transition times (CL to OL Delay and related tables).

Many people raise their redline a bit (Rev Limit) and raise the Rev Limit Fuel Resume to avoid losing power when bouncing off the redline. Some people also raise the Speed Limiting tables.

Anyone care to confim / dispute / add to the above?

Read the full thread here: