"Pocket" Dyno

[Phoenix67]

I just saw the review sa Discovery Turbo yung app called Dynolicious (Dynolicious — Social Meets Performance) kaninang umaga.

Some of the reviews said that it is quite accurate (compared to real dyno machines). So maganda siyang app for race-wannabees.

Merun na bang taga tsikot na nakagamit nito?

[niky]

Don't waste your money. You can get "Car Performance" for Android that does the exact same thing for free. And both are woefully inaccurate, requiring dozens of runs, calibration tests and fine tuning to come close to matching actual performance testing software.

I've used iPhone GPS/Accelerometer apps, Android apps and the V-Box. They're vastly different.

A portable V-Box has a refresh rate of 10 Hertz (10 times per second) and is typically within a tenth of a second accurate, in my experience. We only need to do three to four runs to get accurate figures. Even better, it references the GPS data against internal accelerometer data, to accurately record launch data. No need to calibrate the position of the box, the internal computer figures out which end of the car is facing forward on its own. It also logs altitude data, and can be used to check the slope of the track you're using.

Phone-based GPS typically has a refresh rate of around 1 Hertz (1 refresh per second), give or take a little bit. I've used various apps that use both GPS and accelerometers. The Accelerometer-only apps are garbage. Launch hard and you encounter errors of up to 1-2 seconds. If your car hits 100 km/h in 8 seconds, that's a huge chunk of time. GPS-based ones are typically off by half-a-second to a second, but lag in the apps themselves can cause problems. Most phone GPS's are not only slow, but less sensitive than the V-Box GPS, too... so speed and position updates are very wonky, too.

Using a phone performance meter is like trying to write a thesis on pad paper with chalk. It's crude and messy. You might as well simply calibrate your speedometer with the phone and time your runs by hand, considering how bad that is.

Or you could buy an external GPS receiver for your phone. Those go up to 10 Hertz, which is good, but you're still handicapped by the slow phone app which has to share processing capacity with all your other phone apps... and you'll have to find a performance app that can read the external antenna.

Better to simply spend your money on a V-Box if you want real-world performance data. Or, if you want a performance data toy for your phone, just download one of the free apps. Like I said, "Car Performance" for Android is pretty good, and is one of the less laggy and inconsistent ones, and it gives you the opportunity to see data in 10 km/h increments plus 60-foot rollout, so you can discard garbage data and estimate the actual acceleration times.

Here's some reviews of Dynolicious compared to a real dyno and a V-Box:
motivemagazine.com - Tested: 0-60 MPH Times, Dynolicious iPhone Application Versus VBox
Dynolicious vs. V-Box and Dynojet

Note: the guy didn't "launch" the car hard. In my experience, when you do hard launches, the internal accelerometer and GPS of smartphones fail to detect the launch and give gibberish results. Making them useless for estimating drag-race performance.