While a pretty awesome car from the factory, the early GTR's had a few things that made them a little bit harder to tune from the factory. One of those things which was improved and made a little bit simpler on the later DBA cars was the ignition timing. While the early CBA cars had multiple calculations it went through to find the "Best" timing for a given situation, it made tuning the car to run specific timing much more difficult. Now when you flip the toggle for DBA Ignition timing it will essentially lock out those calculations and run the timing in the table. While there are a few compensations that come afterward, it makes it significantly easier to get the car to run consistent timing.