How to: RTR can mean “ready to race”!
Everything you need to go from the backyard to the racetrack by Gary Katzer
With so many ready-to-run (RTR) cars and trucks on today’s RC scene, it’s easier than ever to get into the hobby. Though early RTRs emphasized low-cost and durability over performance, many of today’s factory-built machines are quite raceable with a few choice modifications and the right support gear. When you’ve finished reading this article, you’ll be prepared to redefine “RTR” as “ready to race”!
1 Out with the bushings, and in with the bearings!
As a cost-control measure, some RTRs have metal or plastic bushings instead of ball bearings, or they may use ball bearrings in the transmission and bushings elsewhere. A complete set of bearings will extend run time and improve top speed by minimizing friction and it will also increase precision by removing “slop” from the car’s rotating parts.
So how do you know which bearings to get? Your owner’s manual is the first stop; it should have a list of optional parts, and a bearing set is usually near the top of the list. If not, check the Item numbers for the kits bushings; the bushing description should include its size, so order bearings with the same dimensions.
You’ll have to disassemble your RTR to install the bearings, so keep the manual handy. If your RTR didn’t Include a manual that covers assembly from the ground up, and you aren’t comfortable tackling the project on your own, your local hobby shop can help.
2 Get the right rubber!
Most RTRs include relatively hard tires that emphasize long wear over sheer grip, and that is exactly what you need for play action. But for race duty, track-matched rubber is the only way to go. You’ll also need new wheels to go with your new tires, assuming that you glued your tires to the wheels or that the manufacturer glued them for you. Selecting replacement wheels is easy enough, but choosing the right rubber can be tricky. The best bet is to simply run whatever the fast guys are running. Visit the track or parking lot where you plan to race, and talk with some of the drivers to learn what they use. You’ll also be able to get some good information about tires for your vehicle from your local hobby shop.
3 Step up to an ESC
More and more electric RTRs are arriving with factory-installed electronic speed controls, which are better known as ESCs. If your machine includes a rotary or wipertype mechanical speed control (MSC), you should upgrade to an ESC if you plan to race. The number-one benefit will be the vastly superior throttle control, and that is a must for racing. You’ll also get maintenance-free reliability (also important for racing) and improved efficiency for longer run times. Plus, the ESC will lighten your vehicle by allowing you to remove the throttle servo.
For as little as $40 you can buy a good, entry-level ESC, or you could go to the other extreme and buy a top-of-the-line competition ESC that costs $175 or more. For most club-level and parking-lot racing, a $50 to $90 ESC will be just fine, and a number of companies offer feature-packed ESCs within this price range. For more Information and a comparison of inexpensive “speedos,” check out the “Low-Buck Racing ESC Guide” in RC Car Action’s April 2002 Issue.
4 Perform a “boing-ectomy”
Most car and truck RTR kits include fluiddamped (“oil-filled”) shocks, but some still use what I like to call “boingers”– better known as friction-damped shocks. The problem with this type of shock is that there is rarely enough friction to provide any real damping.
“Great, but what’s damping?” you as! Without getting into a big physics discus sion, it’s what prevents a car from boun ing on its springs like a pogo stick. In a fluid-filled RC shock, the damping force is created by forcing a piston through fluid, and that force can be adjusted by altering the piston’s configuration or by filling the shock with more viscous or less viscous silicone fluid.
Matching the spring rate and damping to track conditions Is an art, but any sort of damping will give you far superior performance than an undamped shock. Check your kit’s manual for a fluid-damped shock option, or choose an aftermarket set; just be sure to get shocks that are the same length as–or a little longer than-your originals. You can install spacers inside the shocks to adjust their length, but anything more than 5mm longer than stock is too long. You can choose from inexpensive plastic units, anodized– aluminum shocks, or high-zoot, hard-coated aluminum jobs. All are far superior to “friction” shocks!
5 More power!
The sealed-endbell, 540 motors included with many RTRs will get the car rolling, but not very fast. Match your motor to the class you plan to race In. Stock class is best for beginners, while 19-turn or “chameleon-class” is faster for the more advanced drivers, For stock-class racing, motors such as Trinity’s Green Machine 3 and P2k2, Reedy Modifieds’ MVP and “tuner” motors from companies such as Fantom are the hot choices. For 19– turn mod racing, Trinity’s Chameleon and
Chameleon 2 are the class standards, and many companies offer tweaked versions of the Trinity hardware. Take a look at what the fast guys are running!
6 Increase adjustability with turnbuckle linkages
Fixed camber and steering links are standar for many RTRs. Although this is convenient because you don’t have to worry about changing settings, it’s inconvenient when it’s time to dial in your chassis. With a set of turnbuckle linkages, you’ll easily be able to adjust your vehicle’s camber (the angle of the wheels as viewed head on) and front toe-in (the angle of the front wheels as viewed from above). Most kit manufacturers offer steel turnbuckles for frugal folks, but I suggest you go all the way and move up to titanium turnbuckles; they are virtually unbreakable and are very light. Lunsford and Associated’s Factory Team line offer titanium turnbuckles for just about every car on the market; for custom applications, you can purchase turnbuckles individually by length. That wasn’t so hard now, was It? Take pride In the work you put Into your car or truck. When you’ve turned that backyard basher Into a track terror, youll be rewarded with Increased durability, higher top speed and more fun. “Drivers … on the tone!”
DURATRAX distributed by Great Planes Model Distributors (800) 682-8948: duratrax.com.
DYNAMITE distributed by Horizon Hobby (800) 338-4639; horizonhobby.com.
FANTOM RACING (616) 649-9583: fantom-motors.com.
HUDY SPECIAL PRODUCTS distributed by Serpent Inc. USA (305) 639-9665: hudy.net.
MIP (626) 339-9007: miponline.com.
NOVAK ELECTRONICS INC. (949) 833-8873; teamnovak.com. PRO-LINE (909) 849-9781: pro-lineracing.com.
REEDY a division of Team Associated.
RPM R/C PRODUCTS (909) 393-0366: rpmrcproducts.com.
TEAM ASSOCIATED (714) 850-9342; teamassociated.com.
TRINITY PRODUCTS INC. (732) 635-1600; teamtrinity,com.
TRC distributed by Trinity Products Inc,
Copyright Air Age Publishing Sep 2002
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