TT Dyno - Dyno software that can turn data logs from automotive tuning tools into real dyno graphs!

Three Ways to Dyno Test
A Quick Comparison

TT Dyno Our TT Dyno software uses the same principle as a chassis dyno to directly measure the amount of power being produced at the wheels. Instead of using your drive wheels to turn a roller or drum, you use them to accelerate your vehicle. If you have a handheld performance tuner or a device that can log data from your vehicle's computer, you already have your own dyno, so why drive out of your way and pay $75 or more for a handful of runs when you already have the equipment to create dyno graphs even more accurately than expensive dyno shops?
Pros	Based on pure physics. No errors introduced by calibration or equipment maintenance. Accurate, repeatable, and more reliable when comparing dynos from multiple cars/runs. Easily log and correlate measurements like knock retard directly to dyno graphs. Convenient: takes just a few minutes to dyno before and after each mod. No need for expensive performance meters: use your existing tuner or logger. Keep your own records and notes attached to each run for easy reference.
Cons	Must make runs on level surface. Must select an appropriate gear to avoid wheelspin.

Chassis Dyno A chassis dyno basically consists of a large inertial drum (roller) installed under a shop floor. Your vehicle is strapped down, put in gear, and the wheels turn the roller in the floor at wide open throttle through the RPM range. A computer (likely nothing more than an outdated PC) analyzes the speed of the roller versus the RPM of your engine to produce a dyno graph. Note that the dyno must be calibrated and maintained to produce truly accurate results. In most cases, it is easier to find a flat stretch of road than it is to find a perfectly calibrated and maintained chassis dyno!
Pros	Shop will test: no dyno knowledge or equipment needed by the driver. Vehicle remains stationary during test: wheelspin and test speeds not an issue. Shops can often evaluate fuel mixture with wideband O2 while testing.
Cons	Can be difficult to find a dyno shop in a convenient location. High cost not effective for repeated measurements or those who mod frequently. Calibration/maintenance can cause as much as a 15% discrepancy between dynos. Results of stationary testing can differ from real world due to air circulation, etc.

Performance Meter (Accelerometer) Performance meters use accelerometers to detect how fast your vehicle is accelerating. Devices designed specifically to measure vehicle performance normally attach to the windshield via suction cups. A second type consists of software that is installed on popular handheld devices like cell phones and PDA's. The cell phone type performance meters are highly inconsistent because the accelerometers are significantly affected by temperature. Dedicated performance meters perform better but are still highly sensitive to mounting angle, road surface imperfections, weight shift during acceleration, and other factors. These devices also cannot produce true dyno graphs because they are unable to measure engine RPM.
Pros	Relatively simple to use and get instant results. Compact and can be used in any vehicle.
Cons	No connection to vehicle: RPM is not measured so true dyno graphs not possible. Accelerometers are highly sensitive to heat and vibration making them less accurate. Significant errors often occur due to imperfect mounting, launch weight shift, etc. Must make runs on level surface.