Discussion and questions related to the course EFI Tuning Fundamentals
Here in Brazil, most of dyno do not have torque optimization and also is very usual to tune EFIs that do not have a knock sensor (for example, Honda D16 PGMFI in my case). I would like to know the best way to tune using this type of simpler dynamometer, for example, find the MBT during a dyno run and use the data found to interpolate the values of other fields of pressure and rpm. And also if exists a theorical or approxinated safest ignition advance value near MBT, or if there is any other trick.
Thanks in advance.
In that situation where you don't have a knock sensor and you can't do steady state torque optimization, typically you have to do a series of WOT pulls. Start with a safe basemap, do a WOT pull for baseline. Advance spark 1 or 2 degrees, see if you pick up power, and repeat. Once you get to the point of only picking up a small amount of horsepower (or 0 horsepower/torque) for adding spark, you stop.
So in a simple example where we add 1 degree of spark to the whole WOT area of the map:
Baseline run: 200 Nm peak torque.
Add 1 deg: 210 Nm peak torque (+10)
Add 1 deg: 218 Nm peak torque (+8)
Add 1 deg: 223 Nm peak torque (+5)
Add 1 deg: 224 Nm peak torque (+1) . Stop here (total: adding 4 degrees).
Of course you may end up only adjusting it 4 degrees in a certain rpm range, but the principle is the same.