If this month's testing of the Innovate OT-2 system looks eerily familiar, it should. Just two months ago we brought you Innovate's free, downloadable iPhone/Pad/Pod app Logworks, as we tested its abilities to infer our Project DC2's wheel horsepower using only our car's curb weight and an iPhone's built-in accelerometers. You'll also remember that it delivered numbers 10 whp (6.9%) off their actual values as verified by a Dynojet chassis dynamometer. While we excused this margin of error (read below), we vowed to revisit the system on a more suitable platform.
The Innovate OT-2 system can accurately infer vehicle horsepower and acceleration times.
The complete OT-2 system (consisting of the Innovate Open Tune OBD 2 module, and a Logworks-loaded Apple i-device) taps directly into the "brains" of OBD-2-and-newer vehicles, and communicating wireless with a Logworks-loaded Apple i-device, can function as a virtual gauge capable of relaying thousands of engine/vehicle parameters to its user, logging up to 16 of those channels simultaneously, warning its user of preset limits in these parameters, scanning and resetting check-engine-light (CEL) conditions, and in most cases, even calculating fuel efficiency. Working with an i-device's internal accelerometers and factoring in vehicle weight, Innovate claims its Logworks app can accurately infer horsepower and acceleration times. Last month's testing proved how well it works using only vehicle weight and an iPhone's accelerometers (since the OBD 2 module couldn't connect to our OBD 1 Integra), but this month put the full system to use with our Project IS F, testing the OT-2's ability to calculate horsepower, acceleration, and trap speed.
After momentarily geeking out at all the "virtual gauge" possibilities of the OT-2, we hit up the drag strip at Toyota Speedway in Irwindale, CA, where all acceleration testing would take place. With the OT-2's OBD 2 module connected and our Logworks-loaded iPhone in place, we made three passes throughout the night, simultaneously logging 60-foot acceleration, 0-60 mph acceleration, eight-mile elapsed time (E.T.) and trap speed (and more), while the track's own system verified our results. Horsepower was also inferred by the system at this stage, which we verified earlier with a trip to the dyno.
It was initially thought that a Logworks-loaded i-device gave the most accurate horsepower/acceleration results when placed with its power button facing forward in a vehicle. User testing has since showed that the opposite may be true, so this month we test the system with the power button facing the rear of our IS F. Whichever way you choose to do it, the most important consideration is that the device be completely secured throughout testing-the slightest movement in the device will skew results considerably.
Performing a horsepower/acceleration run with the OT-2 system seems pretty straightforward: set up the system, navigate to the testing screen, bring your vehicle to a stop, hit the "start" button, and then floor it across a smooth, flat stretch of tarmac once the system prompts you to do so; the OT-2 will gather the information it needs and stop calculating once acceleration ends (at throttle let-off or braking). Performing such a run at the drag strip-with the complications of burnouts, staging, and a fast-dropping pro tree-proved more difficult. Of our three runs, only one was deemed usable.
The Verdict: FACT
Calculating horsepower and acceleration with the Logworks Apple app might not be the most easy-to-use, repeatable feature of the OT-2 system, but it proved its accuracy this time around. Horsepower numbers were dead on, and 60-foot acceleration, eighth-mile E.T., and trap speed were all within acceptable tolerances compared to the track's official equipment. Still, since the complete OT-2 system taps directly into our IS F's instrumentation, we wondered why it wasn't dead-on. "There's no way to account perfectly for traction loss or suspension squat," explains OT-2's Cort Charles, "or of knowing how accurate the track's equipment is, or a dyno, or the scales used to weigh your vehicle. And even small variances in tire circumference from worn tread or aftermarket wheel/tire sizing can throw off a car's instruments." Maybe not dead-on, but close enough.