Constant RPM Engine Dyno "pull" for SS tuning?

Hi Andre,

We are tuning on an engine dyno and have done the fuel tuning up to 2/3 of RPM limit using method outlined in the PST course.

The Haltech NSP has the ability to track which cells have been traversed and saving the last 2 seconds of data for each cell. You can then go back and do a "quick tune" over selected cells that were traversed.

I tried a 10-15 sec pull at 4500 RPM - Increase throttle and let Engine Dyno Stabilize at 4500 RPM and then gradually increase throttle to WOT. I went back and replayed data and this seemed to work. Since it covers more cells than a traditional power pull i would ASSUME that will improve the map in the areas not covered by a power pull and i'm not unduly beating up the engine diddling and fiddling . .... is this a valid approach? , are there any downsides?

Peter

I think that's a totally valid approach, good way to use both tools (dyno and NSP quick tune feature).

Peter,

That sounds reasonable. I'd just be mindful of time at high load, how much heat that can build quickly, and making sure you have sufficient cooling systems, ventilation and airflow in your dyno room to support the necessary heat extraction.

Yes always mindful of heat. Process is actually only about 20-30 seconds per RPM row, as we do two passes starting from idle and increasing to target RPM - one to get the trace (T key ) and do the quick tune (R key) and a second pass to see the result of quick tune all done with logging on. Huge fans move air thru dyno room, water cooled oil cooler, and intercooler is in temperature controlled water bath, engine coolant runs thru the dyno thermostatically controlled cooling tower. The biggest problem is actually longer term - accumulation of heat in the 1500 gallon water tank from all this cooling plus absorbing engine output.

That's essentially how I do my steady states these days. The only downside is 'driver' error and 'noise' from transients that may or may not be filtered by whichever software's 'quick tune' feature you're using.