All cars come with a specific factory setup that was manufactured to be the best for the stock configuration. Most street cars have to balance everyday comfort, fuel economy, and performance on a variety of tracks. Acceleration is always sacrificed to some extent, meaning that stock cars can benefit from adjustments that optimize straight-line performance.
When you upgrade a car, you often encounter one or two (or both) of the following problems:
- You spin the wheels through the first 2 or 3 gears, whatever revs you launch in.
- You top out in the highest gear before the race is over.
This is where tuning the gears will help you achieve better times.
If you’re spinning the wheels too much, an excellent first step is to reduce the first gear ratio, hence reducing torque. Try to stay on the edge of the grip (just a little wheel spin is optimal) when launching with reasonably high revs. Ignore the other gears for now.
Once you’ve found the right first gear, you’ll want to adjust the remaining gears in such a way that none of them is too short or too long. You should spend a little more time in each subsequent gear and finish the longest 1-mile race close to redline in the final gear. You can then test your setup in shorter races to make sure you finish each distance close to the redline in the appropriate gear (typically 3rd or 4th in 1/4 mile).
See also: Graphs Analysis and What is tuning? in the Tuning section of the FAQ.