e is a much-used name for the event arguments to event handlers. It looks like this: 

public class OnDataReceivedEventArgs : EventArgs
{
    public OneProcessedSample processedDynoSample { get; set; }
    public OneProcessedSample averagedDynoSample { get; set; }
}

is transmission loss available as a variable or do i have to create it using enginehp-wheelhp?

Transmission loss is the negative Wheel torque and Wheel HP during the retardation run

Yes so if i want to apply a function to it, whats the easiest way?

The software only evaluates transmission losses after the run is over, not on the fly. You need to find the max RPM, then you do some sanity checking on the data recorded after this (the retardation part), for example to see that RPM is constantly decreasing and torque is always negative, etc. 

Is that not already done in order to get the enginehp figure? 

Yes, it is part of the calculation of engine HP/torque. But it is not saved, it is just exists for a brief moment when the engine HP/torque is calculated.

Could it be saved?  I want to apply an algorithm to it based on input torque to try and improve it's accuracy.

No, not the way the plugins are designed today, you can only create new parameters that are recorded during a run.

But I could add your idea to the code possibly. Can you share your idea (maybe email is better jostein@yourdyno.com).

While your adding more variables to the datalogging, Could you add the RPM its set to hold at. Save me from having to OCR to read the text on the form.

Yes, that's an easy one, will do! 

@bmgjet the brake target RPM is already available. It is DynoDataConnection.targetRPM

Awesome, Didnt see that there lol was looking in the polleddata.
Can I change my request then to triggering rpm up and down lol. Sure the shortcut key method im using works by if yourdyno form loses focus to a background program then it stops working lol.

@bmgjet yes sure. I will make a manual target RPM writable. 

Another option is to use the brake sweep for example. The sweep is fully accessible from a plugin via Settings. Like this: 

• Settings.Properties.Settings.Default.powerSweepStartRPM
• Settings.Properties.Settings.Default.powerSweepStartDelay
• Settings.Properties.Settings.Default.powerSweepEndRPM
• Settings.Properties.Settings.Default.powerSweepRateRPM