I have been geeking out on my best friend's 2016 mustang. He's got an OBD2 port bluetooth scanner that can datalog using his phone in real time.
I wrote some script in python and R to try and calculate HP & Torque. Unfortunately, the numbers I'm getting are considerably lower than I expected. The Mustang GT with PowerPack3 should be making ~430 rwhp. In the graph below, the red line is RPM, Blue is Power. I calculated the power based on the weight, velocity, and rate of acceleration. Happy to get into the formulas if you want. It's slightly smoothed (averaged data over 0.2 seconds). Each recorded point is ~0.036 seconds.
Anyways, 4th gear looks really weak at ~300 rwhp. We'd kind of expect to see more numbers like what we see in 2nd gear. I was just wondering if anyone here has experience comparing what they see on the dyno, to what they're getting from datalogs? Is it usually significantly lower in the real world than on the dyno?
Booyah! After accounting for air resistance & smoothing out the datapoints:
Many "power pack 3" S550 Mustangs have dynoed on youtube at ~430 rwhp on the dyno. So, for the real world, this looks pretty believable, but it will still inevitably be off by the cumulative errors in the DA correction, my best guess in the Cd & frontal area of an S550 Mustang (.35 & 24 ft^2) error & imprecision in the datalog, spikes due to kinetic energy transfer between the rotating assembly and tires. I'm thrilled to see expected ballpark numbers!
Did not update the legend in this new pull with the Dark Blue AFR curve toward the bottom of the graph.
Graph from a 3rd gear street pull today. This one shows a blue and green line from a pull in a single gear from 1500 to 7500 RPM (hitting redline). The blue and green curves look a lot more like a what you'd expect to see on a dyno since it's one continuous pull without shifting.. A peak of around 395/350 rwhp/rwtq. This is lower than most dynos in the 435 range, but in the real world, you're spinning those front wheels and tires, and dealing with other issues, as well.