Tuning for AFR December 10 2014
How a car drives on the road is a very important part of owning a modified car - The power that is developed and the driveability, air/fuel ratios are a vitally important ingredient. Within the afr curve, you want the engine to have the most performance, and safety built in. Going too lean can cause pre-ignition, and/or detonation which are both detrimental to the life of the motor. Going too rich can cause some hesitation, spark blowout, and even consume too much of available injector headroom.
Most people think that because the engine may be Direct injected, you are going to make the most power on lean fuel curve, so we did some testing. This is the same car, same day, and we tested running mixtures of 12.0, 11.0 and then 11.5. As you can the power difference between all of them is within a coupler percent. The leaner mix will make a little more power up top, the richer mix will spool the turbo faster, and then the 11.5 mix has the best balance of both. Here at Freektune we used these results to create all of our base calibrations.