Nate S
Well-Known Member
Was looking for something else on my iPhone and came across "PerfExpert", an app for 0-60, 1/4 mile -and- dyno. So I dropped the $12 and got it. Most of the shitty apps of this sort use the gps alone and not surprisingly they aren't too accurate. This however uses the three accelerometers in the phone and does a great job. Works best with a manual tranny of course but should be fine with an auto above the stall. You plunk in all sorts of info and get on a straight, flat road. Start at zero and get to the bottom RPM of the gear you're testing in and floor it through the gear. App does the rest. A quick test in my stock Tacoma has an HP curve identical to the factory published curve. Lots of data out there on people with identical app and dyno curves. Looks like some fun to be had here and a great way to test tuning. Corrects for atmospheric conditions too.
Maybe this weekend I'll try it in the Plymouth.
These are from the app and some dyno info from the factory. I obviously took my foot out of the gas earlier than they did. Anyway, a neat app and accurate. Obviously measures wheel hp and has a converter (about 18%) for engine HP. You can add whatever you want for gross hp manually. Website will even let you lay one chart over another for comparison.
Maybe this weekend I'll try it in the Plymouth.
These are from the app and some dyno info from the factory. I obviously took my foot out of the gas earlier than they did. Anyway, a neat app and accurate. Obviously measures wheel hp and has a converter (about 18%) for engine HP. You can add whatever you want for gross hp manually. Website will even let you lay one chart over another for comparison.