Discussion and questions related to the course EFI Tuning Fundamentals
How would you go about changing the ignition at a higher RPM? Lets say 7-8K rpm range. Wouldn't the engine heat up too much to hold it at that rpm on a dyno to find peak torque?
Also, how do you determine what gear is best to use when doing anything on the dyno?
We tune the engine in the way it will be used so while we use steady state tuning in the cruise and light load areas (where the engine would be running in steady state conditions), at higher rpm we will switch to performing ramp runs to simulate the way the engine operates when we're at WOT. This also limits the amount of load/heat placed on the engine. We demonstrate this in our pPractical Standalone Tuning course if you want a better understanding of the process in a step by step format.
There isn't a gear that we 'must' use on the dyno. Normally we would select a gear that's close to 1:1 which would probably be 4th gear in a 5 speed gearbox or 5th in a 6 speed. It's not super critical though and the biggest consideration is that as we use lower gears we increase the torque multiplication seen at the rear wheels which can make the car more likely to wheel spin. A higher gear reduces this likelihood but then means the road speed will be higher at redline.