Forum » EFI Tuning Fundamentals » Tuning without torque optmization and without knock sensor

Tuning without torque optmization and without knock sensor

EFI Tuning Fundamentals

Discussion and questions related to the course EFI Tuning Fundamentals


Page 1
Author
400 Views

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.