Tested and well reviewed by Sticky (in Scootering January 2013) Sticky: "The fact that it works at all - let alone working this well - is just plain wizardry"
This is the Free Version, no values are displayed at the result screen and results cannot be saved.
This app is very technical and you need to clearly understand the instructions.
This App unlike all other Dyno Apps out there doesn't use the acceleration sensor of your device or the GPS speed, because both aren't exact enough to achieve a good measuring result.
It works very similar to the software of a dyno, only that with the SIP HorsePower Dyno, your test runs will take place on the street and not on the dyno. Instead of accelerating a massive metal cylinder like on a dyno, the scooter is being accelerated on the street while riding it. Put simply: get on your scooter and ride at full throttle. The quicker the acceleration of the scooter, the greater its performance. So the software has to determine how fast the scooter is accelerating and this is done the easiest way by the digital signal processing of the engine noises. Some of you will think now: “I see, the louder, the higher the performance of the engine, now that’s more of the common gibberish!”
We all learned early through our mechanics career that this just ain’t so. Sound levels really are no indication for performance at all. The SIP HorsePower Dyno can measure the rpm of the engine not by analyzing the sound level, but by analyzing the exact frequency. The faster the rpm increases, the better the performance of the engine (all other conditions being identical). Luckily, the gear ratio of our Vintage scooters remains the same as long as there is no shift of gears. This way, the speed can be calculated from the rpm just as you can then calculate the performance by the change of speed which equals acceleration. To obtain the most realistic performance value possible, it is recommended to enter a couple of values as precisely as possible:
- overall weight - tire circumference - Cw-Value - air pressure - temperature - gear ratio
If you know the Windows programs SIP Dyno and GSF Dyno, you know how exact these measurements are. You can find a couple of comparisons between GSF Dyno, this App and a real dyno (P4) at my Google+ Page.
- This App only works if you can shift the gears. So it works for scooters like Vespas or Lambrettas. The method doesn’t work with automatic scooters.
- This App might not work for cars, which have a good acoustic insulation.
- There have been good results with the GSF Dyno and cars or motorcycles. However i cannot test this, since I only drive a Vespa. I will update this if I get some good feedback from guys using this App with other vehicles, but until then I cannot promise any good result.
Please be aware that this is a very technical App. I cut the important things down as much as i could and added a "?-Button" on every page inside the App. Please read the information carefully. If you have any problems, contact me and I will guide you through.