DIY Network

Radio Control Dragsters: Track Basics From "Radio Control Hobbies" episode RCH-403

In this episode of DIY's Radio Control Hobbies, host Chris Chianelli visits a RC track just outside of Greensboro, North Carolina that specializes in RC dragsters. These amazing racers can reach speeds in excess of 80 mph in less than 2 seconds.

In this segment, Chris visits with Tim Cross, President of the International Model Drag Racing Association (IMDRA). He also visits with Adam and Randy Pace, a father-and-son team who travel the country competing in RC dragster events.

advertisement

Figure A

What's The Frequency, Chris?

At this drag strip raceway outside Greensboro, North Carolina, more than 100 racers participate in some hyper-accelerating competition. As with any public RC event, or anywhere that multiple RC models are being run, proper control and monitoring of radio frequencies is a must, and a vital safety consideration. Two radio transmitters on the same frequency could produce some problematic -- and dangerous -- results, such as a race car being launched by accident at an inopportune moment.

The safety system in use at this track is a frequency board (figure A), much like the ones used at many RC airfields. Each radio-frequency number is displayed on the board. Each radio transmitter in operation at the track must match one of the numbers on the board -- and only one transmitter is allowed to use that frequency. To eliminate any possible confusion, each number has a corresponding pin with the number displayed. Each radio operator places the pin on his or her transmitter, displaying the frequency that radio is using. Only a transmitter properly displaying the pin and corresponding frequency number is allowed to be turned on.

	Tim Cross, president of the International Model Drag Racing Association.
	Figure B

The Track

Tim Cross, President of the IMDRA, explains to Chris how the "Christmas tree" starting system and the computerized scoring system works.

Measurements critical to drag racing are accurate elapsed time, reaction time and miles-per-hour measurements. These are measured using sensors built into the start and finish lines. There is also a miles-per-hour sensor located at 122 feet from the starting line. All of these measurements tracked using a computer scoring system and displayed on a laptop in the race-control tower (figure B).

The sensors on the track are protected by a wooden ramp. If a dragster hits a side rail or any of the ramps, not only is it disqualified for that run, but it also might lead to extra time in the pits.

Figure C

In drag racing, the critical variable is reaction time -- from yellow to green light on the starting tree (figure C) and how long it takes the driver to react. The amount of time elapsed between the light turning green, the trigger on the transmitter being pulled and the racer starting to move makes the difference between a win or a loss. Through experience, the drivers learn to anticipate precisely when the light will change from yellow to green. Knowing the exact reaction properties of the vehicle, and ensuring consistency, are factors that are of supreme importance for the competitors.

	Adam and Randy Pace.
	Figure D
	Figure E

Electric Speed

In addition to providing damage control, the track's pit area at the track is a place where one might find out how the drivers pull times under two seconds. That's where Chris visits with Adam and Randy Pace, a father and son team that travels the country competing in RC dragster events.

Adam and Randy race electric dragsters, and the one entered in this race is equipped with 21 nickel-metal hydride battery cells (figure D). It's powered by a cobalt motor that has a total of six magnets. The carbon-fiber chassis weighs only 47 ounces. This particular racer (figure E) has won in three championships so far.

In the segment that follows, Chris explains "bracket racing," and gets to try his hand in racing a more standard RC vehicle against one of these super dragsters -- with a handicap calculated in to make for a more leveled competition.

RESOURCES :

Special Resources for Radio Control Hobbies, episode 403

Megatech International
North Bergen, NJ
www.megatech.com

Grand Motorsports
Mount Vernon, IL
www.grandmotorsports.com

Team Walbern
www.teamwalbern.com

International Model Drag Racing Association (IMDRA)
www.imdra.com