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Premium Member
4,940 Posts
Discussion Starter #1
I found this digging through some old stuff. I'm not sure who wrote it but it was once on the QSAC site.

QSAC & Quarter-Scale Primer

Defining "Quarter Scale"

Quarter Scale is, as it is named, basically, one 1/4th of full-scale in most respects, (except for weight and horsepower --- it would be interesting to have a 200hp, 850lb, four foot long R/C car, but verrry impractical!), a scaled-down version of many of the cars you see in a typical racing event shown on television, and featured in many magazines. They include Winston Cup-type Stock-Cars, Busch Grand National-type Stock- Cars, Craftsman Truck Series-type Super-Trucks, World of Outlaw-type Sprint Cars, Outlaw Late-Models, etc., all oriented toward pavement-oval racing. European Quarter Scale is oriented toward road-racing, which, for some reason, is slow to catch-on in the US.

Quarter Scale is the largest of all the Radio-Control Race-cars, and more closely resemble their full-scale counterparts than do any of the smaller scales.

Quarter Scale is less expensive and very much safer than their full-scale counterparts, (we've never had any drivers hurt when they crashed during a Quarter-Scale event) but still very real. Any seasoned Quarter Scale driver will tell you he can "feel" what his car is doing. In addition, almost any set-up parameter available on a full-scale race car is duplicated on the Quarter Scale equivalent. Winning requires a combination of skills; set-up, as well as driving! (Jump to Quarter-Scale Gallery for pix of typical chassis/suspension.)

Quarter Scale Cars are not toys; you won't find them on the shelf at Toys 'R Us, or the local hobby shop. The NASCAR-type Stock- Cars are four feet long, weigh 30lbs, and, depending on the track, can exceed true-speeds (not scale) of 80MPH!

Organized Quarter Scale Racing events take place at the local, Regional, National, and International Levels.

Driving a Quarter Scale

Because they are driven from a distance by means of a radio transmitter with a small steering-wheel, and trigger-actuated throttle and brakes, it is sometimes difficult for the beginner or novice to achieve that "feel" mentioned above. But, with time and practice comes experience and skill. A person "moving-up" from a lesser scale will have no problem driving a Quarter Scale, as they are, when properly set-up, easier to drive than any of the lesser scales.

Quarter-Scale Differences

Primarily in the areas of size, true-scale appearance, set-up adjustability, and realism. Quarter Scale emphasizes optimizing the competitor's set-up, as well as driving skills; and particularly enjoyment. Sharing with, and helping other competitors is the rule, rather than the exception in Quarter Scale. QSAC uses the term "Knowledge-Transfer" frequently in many of its Newsletter features, and strongly encourages competitors to help each other "get the cars stuck". This attitude is not altogether altruistic, since it is much better to have ten good-handling cars in a race than six that handle well, and four others that are, in essence, "30lb-barely-guided- missiles". It makes for more competitive, fun racing, and a better "show" for the spectators. This attitude is the exception, rather than the rule, in the smaller scales.

Another, very important difference, is the engine specs. QSAC mandates that only one specific brand of 23cc two-stroke engine is allowed, and, with the exception of the Outlaw Late-Model class, it must be bone stock. At major events QSAC utilizes a pre- and post-race Technical Inspection procedure, impounding the top four cars in each class, and performing a comprehensive external and internal inspection of the car including weight, width, height, tire-size, and spoiler, as well as engine tear-down inspection.

Racing in Quarter Scale

Race formats in Quarter Scale closely follow their full-scale counterparts, with one major exception: the races are computer-scored utilizing car-mounted transponders that, when passing over a sensor-loop imbedded in the track-surface, keep track of lap-time, track position and number of laps automatically (our full-scale brethren are just now catching on to this). The number of active transponders available with these systems is ten, therefore each race is limited to ten cars. The lesser scales have a similar limitation. However, there the similarity ends. While the lesser scales limit the race lengths by time or fuel-tank size, Quarter Scale races are oriented to numbers of laps, like their full-size counterparts.

Class specifications and race formats are established by the QSAC Official Rules. Stock-Car classes may run as many as 500 laps, and require "on the fly" pit-stops for fuel, since the fuel-tank sizes for each class are specified in the Rules. Classes such as the Super-Trucks mimic the full-scale events, and are formatted to run two 100 lap segments, separated by a 5 minute "break" during which any sort of maintenance (refueling, tires, spring/shock changes, etc) may be performed.

Local tracks have the option of using single-car time-trials, or a pill-draw, to establish starting positions in the Qualifying heats (of which there are two rounds, varying in length from 20 to 50 laps) to earn positions in the "mains". Heat races are usually limited to six competitors. The number of "mains" is dependent on the number of cars entered in a particular class. Each main is populated with cars in whatever positions earned from the heats. Every competitor will run at least one "main".

Example: Say the Winston Cup-type class has 30 entries--- there would be two rounds of five heats of six cars--- they would populate an A, B, C, and D-main of six cars and an E-main of six, from which the top four cars would "bump-up" to the D, making it a ten car race, the D's top-four bump to the C, which would "bump" the top four, and so on, up to the "A". Laps raced in the mains range from 50 for the E and D, 75 for the C, 100 for the B, on up to as many as 3-500 for the A. So, as you can see, a racer who had misfortune in his/her pair of heat-races could, if they got the car adjusted right, raced all the way through from the E to the A, for as many as 775 laps total! It has happened!

Premium Member
4,940 Posts
Discussion Starter #2
Q & A

I found these Q & A too...


•What are the various classes of Quarter Scale Cars?

•What kind of fuel do they use?

•How do I find a place to race?

•How fast do they go? (most frequently asked)

•What does it cost? (2nd most frequently asked)

•How do I get started? (3rd most frequently asked)

Q1. What are the various classes of Quarter Scale Cars?
A1. The principal classes of Cars being raced in most parts of the country are the Winston Cup-type, Busch Grand National-type, and Novice Stock-Cars, as well as the Craftsman Truck Series-type Super-Trucks. However, there are pockets of activity around the country where WoO-type Sprint-Cars, Super-Modifieds, Outlaw Late-models and even Indy-Cars are run on a local basis. It does seem, however, that with the increasing National TV exposure of NASCAR Stock-Cars and Race-Trucks, that they have become the predominant classes in QSAC sanctioned racing through-out the country.

Q2. What kind of fuel do they use?
A2. Since the engines used are 23cc two-strokes, a gas/oil mix is required. QSAC's Rules specify that any Gasoline (including that formulated specifically for racing) is allowed, as long as it is commercially available. The relatively low compression-ratio of the engine does not demand high octane, but since the engines are enclosed within the body, hot weather heat build-up can be a problem, and vapor-lock can result. Many racers buy racing fuel, not for its octane rating, but for its RVP (Reid Vapor Pressure) rating--ie: resistance to vapor-lock. In cooler weather conditions (up to about 70 degrees), 87 octane unleaded pump-gas will provide more power than the more costly racing fuels, but can cause vapor-lock if ambient temps rise. Any good two-stroke oil can be mixed with the gas in ratios from 32:1 on up to 100:1 for the more efficient synthetics.

Q3. How do I find a place to race?
A3. There are quite a few purpose-built Quarter Scale tracks through-out the country. There are also many suitable tracks originally built for racing smaller scales of gas/electric cars. Many of these latter facilities are unaware of Quarter Scale and may need only to be approached to start a program at the track. Meanwhile, click here: Where do we race? to jump to a list (some with pix) of facilities currently sanctioned by QSAC.

Q4. How fast do they go?
A4. Here's a question that everyone asks the first time they're exposed to a Quarter Scale Car, even if it's sitting on a table at a static-display! The answer is more track size-dependent than anything else: on the average track the laps speeds fall in the 40-45mph range, with a top, straightaway speed-range of 50-60mph. On really big tracks, speed is limited primarily by available gearing. Example: On a 1/5th mile go-cart track in North Carolina, a couple of Quarter Scale cars invited to test there were turning 75mph lap-speeds(!), and were limited because they didn't have the proper gearing to go faster. Those lap speeds translated to straight-away speeds in excess of 80mph! So, as you can see, the potential, given unlimited gearing and a long enough track, could easily exceed 100mph, though we seriously doubt anyone would purpose-build a track big enough to allow that kind of speed.

Q5. What does it cost?
A4. How much you spend on Quarter Scale racing depends entirely on your attitude! If you approach the sport as an enjoyable diversion from your day-to-day responsibilities and focus on setting-up your car, driving it, and having fun, your costs will be quite moderate. However, if your immediate goal is to win, at any cost, and insist on having every on and off-track advantage that money can buy, your costs will be much greater. If you are a beginner and want to advance to the point where you are competitive within your class, the most effective way is practice practice, practice! This will have a much bigger payoff than installing trick new tires or Titanium chassis parts, and is a lot more fun and cheaper, too.
For some people, half the fun of racing is designing and installing modifications to the chassis or suspension. You can certainly express your ingenuity and mechanical aptitude in this way, and if the mod doesn't work, you can always remove it. The costs associated with this kind of activity are up to you; but they aren't closely related to the number of races you enjoy or the race results. New car costs range from $1200. to $2500. (not including radio-gear, which can cost from $100.-up.) and the cost doesn't necessarily reflect the fastest or the winning-est. There are always plenty of used cars available for prices ranging from 45 to 70% of the original list. These cars are usually in very-good to excellent condition, and are usually being sold so the owner can purchase what he considers to be the "newest, trickiest, best" available. The interesting thing about Quarter Scale vs. the Smaller scales is that product-development is evolutionary, rather than revolutionary: changes are made incrementally rather than wholesale, and planned obsolescence is not part of the equation, as is the case in other scales. The best idea before buying a car, or even a radio set-up to go with the one you just got, is to go the track, talk to the racers and find out what they're using. They've learned from experience what works best, and won't be shy about sharing their knowledge with you.
Tires-- In the long run, here is where most of the recurring costs of the sport lie. If you're buying a new car, the manufacturer will install the most appropriate tires and set-up for the tracks you will run the most (if you let him know, up-front, where that is). There is a plethora (many) of tire compounds available for Quarter Scales, and the individual Car manufacturer has, for the most part, tried them all. He knows what works best on his brand of car, be it new, or a couple of years old--- listen to what he tells you. Another source is to check with the guys running at the tracks you'll run---ask them, they'll tell you. There's no sense in "reinventing the wheel" (no pun intended) when you can get the straight scoop and avoid buying a whole variety of tires just to prove to yourself what works the best for you!

Q6. How do I get started?
A6. First, click on Where do we race? to find the racing venue nearest to you. You probably won't find one in your town, but don't be discouraged, many Quarter Scale racers travel one to four hours to race at a facility they consider their "home-track". There's just that much fun racing Quarter Scale, so they don't care about the "commute"! After you've located the nearest facility and called the contact person or persons to find out the local schedule---before you do anything else---MAKE A TRIP TO THE TRACK ON RACE-DAY! Talk to the owners or club officers/members, talk with the racers, get answers to the questions you have, but most of all, take time to observe how much fun the folks are having! After making that visit, if you're fired-up, (and we think you will be) get back on this site and click on I'm interested, where do I get one? to get a complete listing of suppliers. check'em out, make your choices and get started on some of the most fun you've ever had in your life!
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