Detroit Region SCCA

Introduction to TSD (Time-Speed-Distance) Rallying

A road rally is contested by a two person team in ordinary cars on regular roads, within the legal speed limit. The challenge is to drive on time; not early, not late (it's not a race). Each team needs a watch which can be set to rally time; something to write on and write with. For night rallies it is a good idea to have a map light, flashlight or other interior lighting so you can read instructions.

Cars start a rally at one minute intervals. The first section of the rally is called the odometer calibration run and allows you to compare your mileage with the rallymaster's. If you have a trip odometer in your car you can zero it at the start and use this. Otherwise, write down the odometer mileage. You will have a specified amount of time to reach the end of the odometer calibration run. You wait at that location until the given time has elapsed, then leave, following the directions given and travel at the specified average speed. You will encounter checkpoints at various locations along the route. After you pass the checkpoint sign and the timing car, stop safely off the road and walk back to the timing car to get a sticker with your time and a critique slip containing information on when and where to start the next leg.

Since the rallymaster knows how fast you were supposed to travel, and how far you went, it is possible to calculate the exact time when you should arrive at the checkpoint. The checkpoint crew times your arrival with a very accurate clock. Your score will be the difference between when you should have arrived and when you actually arrived. Points are given for being early or late. This is a contest of precision, not a race. If you are late at one checkpoint, you can not make it up by being early at the next. The score for each leg is separate. Scores for all legs are totaled and the lowest score wins (just like golf). And, just as in golf, it takes some practice to get very good scores.

Regardless of whether you get very good scores, or just scores, rallying is a lot of fun if you like to spend time in your car, see some scenery and spend time with a congenial bunch of people. Rallies usually end at a location where food and drink are available. You can join the crowd in discussing how the event went and how you did, while you wait for the scores to be calculated and trophies awarded.

written by Jim Micklee-mail


Classes commonly used by DETROIT REGION SCCA
Equipped:
Unlimited equipment.
Limited:
Any mileage measuring equipment and any calculation equipment without direct odometer input (lap top computers, hand held calculators, etc.).
Stock:
Stock odometer system and any non programmable calculator with not more than one memory. Curta calculators are allowed.
Vintage:
Vehicle at least 20 model years old. Mileage measuring and calculation equipment must be mechanical.
Novice:
Any team where the total number of rallies run by the driver and navigator combined does not exceed six (6). Equipment limitations the same as Stock Class.

Tour Rally Rules Summary which governs most Detroit Region Rallies

Detroit SCCA Return to
Detroit Region SCCA Rally HomePage

This URL: http://pages.prodigy.net/murphybr/detrally/tsd_raly.htm

Date Created: January 23, 1996
Last Modified: February 12, 2000

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