[jspaeth]

Steve, here's 3 questions for you!

In this coming year, I hope to get some time on a Dyno Dynamics and do some steady state tuning to refine my fuel and timing maps.

1) Once one gets "into the groove" of how to do this, how long would you say nailing down a single cell takes?

If I understand correctly, one would lock in the RPM for the desired cell, and then use the throttle to change the load.

Once locked in on a cell, I would guess you first get the AFRs into check and then start slowly bumping the timing and monitoring the torque output.

...given this is all occurring in "real time", I can't see how it would take any more than a minute or two to nail down a single cell.

...The reason I ask is because I am wondering how long one should expect it to take to do a whole 20x20 map.


2) On a load-bearing dyno, can you also go into cells with a load well below that of where you would be if you were at constant speed or accelerating?

For example, can the dyno apply a load to keep the engine spinning at 5000 RPM but with your foot completely off the throttle so that you can tune the lowest load cell in the map at that RPM level?

2b) Can you get into cells that seem like they are not physically meaningful (i.e. 2000 RPM and 10 psi).....if not, what does one do for these cells? Does the car even ever see them (maybe on fast upshifts?)


3) In practice, if you wanted to do a REALLY good job tuning a car (let's say your own car, for example)....

Do you hit EVERY SINGLE cell....or do you every other (would reduce a 20x20 grid down to 100 cells rather than 400)....or what...?

Hit every single cell in the heavy load areas and interpolate in other areas? Just curious.

Thanks!