A key feature of rallies is tracking distance. In the rally instructions, the location of all questions is given by way of the distance (in miles and kilometres) from the start point. So you need to know how far you have travelled in order to know when to look for the answer to a question.
This can be done simply with the car's trip odometer (I have done several rallies in this manner). However, sometimes the odometer is not totally accurate, so you will have to manually calculate the gain/loss over distance (a correction chart can help with this). More importantly, if you make a mistake, or take a wrong turn (and you will!) you will have to allow for the extra distance travelled, and so recalculate the location of every question.
This process is greatly simplified if you have a rally meter installed in your car.
What is a Rally Meter?
Like the odometer, a rally meter tracks the distance you have travelled, but it has a number of sophisticated features - most notably, the ability to be reset not just to 0, but to any number you like. This means that if you do go off track, but then work out where you are meant to be, and so find the next question, then you can reset your rally meter to the exact mileage/kilometreage for the question. You will therefore be tracking correctly again for the subsequent questions.
There are a number of different rally meters available on the market. Examples include:
- Halda Tripmaster and Twinmaster
- Brantz
- Terratrip
Once you have bought a rally meter, you will need to have it installed in your car, and you will have to calibrate it.
Rally Meter Instructions and Aids
You may find the following downloadable documents helpful.
- Rally tripmeter comparison chart (©2006 Jeff West)
Useful information about the features of several brands and models. - Correction chart for a conventional vehicle trip odometer
An Excel spreadsheet for those who do not have a rally tripmeter fitted to your rally vehicle.
Terratrips
- Terratrip 1, 202+, 303+ manufacturer's instructions (© 2007)
- Simple transistor-based interface
To connect a typical electronic speedo sensor/sender to a Terratrip 202+ or 303+ - Terratrip Calibration for Dummies (© 2005)
- Terratrip 12 pin plug wire socket terminal removal tool
Ever wondered how to get those pesky Terratrip socket terminals out of the 12 pin plastic plug that fits into the back of the Terratrip? - Terratrip 12 pin plug socket connection
Haldas
- Halda calibration spreadsheet (© 2005 Jeff West)
- Halda cable and adaptor table (© 2006 Jeff West)
Other useful links and information
Halda accessories (as at 31 Jan 2006):
- Ken Smith
Cootamundra
Phone: 02 6942 1197
Huge range of Halda gears, cables and T pieces for sale