TSD Rally Computer is an iPad app designed to simplify computations necessary to navigate a traditional time-speed-distance (TSD) automobile rally that requires manual entry of odometer distance.

A TSD rally is comprised of stages set along a route defined by written instructions. The first stage is the Odometer Check stage that allows you to calibrate your car’s odometer with that of the Rallymaster’s odometer.

In later stages you will follow a course at a particular average speed that will change from time to time at places that are generally unknown in advance.

In order to drive the course at the prescribed speeds, you must keep track of your odometer reading along the way. You may get the odometer measurement from any external GPS or odometer or app you like.

Apple-approved MFi game controllers can be used with the TSD Rally Computer when connected via Bluetooth.

The TSD Rally Computer allows you to do all this and much, much more. For additional documentation, download the User’s Guide.

Features of the TSD Rally Computer:
- Clock time in either minutes and seconds to tenths of a second or decimal minutes to thousandths of a minute
- The clock is a 24-hour clock to simplify computations
- Distance measurements in either miles or kilometers
- One button click to reset default conditions for starting a rally
- The internal iPad clock can be adjusted to match the official rally clock
- The car's odometer reads up to 99.99 miles or kilometers and can be incremented by simple button clicks including buttons to increment by one of four amounts shown in the selector below the odometer. The optional amounts are 1.00, 0.50, 0.10, and 0.01
- A "Settings" button in the top menu bar allows access to the app settings from within the running application including settings for display of certain items
- Calibrate the car's odometer to the official rally odometer on the odometer check stage via a popup
- Change average speed (CAST) with a scroll wheel and make incremental changes with either of two buttons
- Preselect the next CAST to simplify the process of changing speed on each leg
- The CAST button can be deactivated to prevent accidental touching
- Preset CAST speeds and times to travel one mile or kilometer at those speeds with via a popup
- Use scroll wheels to quickly and easily change time, speed, or distance throughout the app
- As time passes and as the car's odometer is incremented, the actual speed over the course is compared with the expected speed. The difference in seconds or hundredths of a minute is displayed along with an indication to either "Speed Up" or "Slow Down" to stay on pace
- Pause or gain time on any leg with a toggle button and at times chosen with scroll wheels
- Handle off-course corrections to time and distance with a toggle button
- Record "splits" of time and error at any time with a Control button
- Set Next Departure Time (NDT) and have the time tick down on the master clock and autostart CAST
- Use a handy popup to perform ad hoc computations of time, speed, and distance given any other two variables
- TSD Remote is a companion heads-up display app for the driver that synchs information with the navigator's TSD Rally Computer
- Apple-approved game controllers are supported via Bluetooth
- A pair of stopwatches with pause and split times may be operated at any time. You may toggle between each stopwatch with the touch of a button.


Note: Use of the TSD Rally Computer during any particular rally will be subject to the rules and instructions governing the rally and may also define your category or class among race participants. Some rallies may, in fact, prohibit use of this app.