The tune can change the way the vehicle shifts gear in an auto, it can change the speedo calibration after a change in tyres or diff gears, it can increase the boost of the turbo, it can remove torque limiting features, it can make it run richer or leaner as needed, it can adjust the tune to suit fuel economy or power. The more you upgrade your car with better exhaust and intakes, etc the further away from the standard tune your car needs to be. There are many things the tune can do, and it changes the tune to suit all of the improvements you have made along the way.
Sometimes fitting a free flowing system can drop the revs when idling, which makes the car vibrate. This can be lifted back up again. Sometimes there can be popping in the exhaust on backoff. This is because the standard tune is still adding fuel on deceleration, and this can also be tuned out. If you look at the screenshots, these programs detect knock retard, injector duty cycle, O2 sensors, spark.
 |
Torana Race Car on Dyno |
|
 |
