I am often asked which is my fastest slot car. There are several possible answers. The Panoz 1447 was the fastest by lap count on our favorite track. Here is the story:
Once a year on our 55 foot Carrera track “Quadrophenia” we held a 1 hour LeMans race. 1/24 scale time is one hour… Rules were simple to allow for creativity. We required scale appearance of a car that competed at LeMans, unlimited magnets and free design. The race format itself is unique and challenging: Four 15-minute stints with 20 second change over, no marshals, (get your own car) no track calls, 40 amp power supply turned up from normal 14 to scary-fast 21 volts.
The combination of high voltage, one hour non-stop and unlimited traction magnets presents a conflict between speed and durability. In fact, the rules state that if the car was not running at the end of its hour trial, none of its laps would count. Lap times in our Lemans races have been about one half what good magnet cars run in normal races. Because of that, most cars required some attention to cool or repair, on the clock. One year, the winner had to replace a crown gear, another year the winner had to replace both rear wheels, and a car that had scored the most laps lost when its motor failed with seconds to go! So the challenge is not only to build and drive the fastest slot car, but also for the car to go the distance.
To respect the LeMans character of the race, a minimum body weight rule was given. This was to preserve real car appearance and permit use of a wide variety of available cars. Minimum body weight was 45 grams, the weight of the heaviest off the shelf Lemans body off the shelf car we could find. Lighter weight bodies would need to add weight to the body. Normally, when running magnet cars, lighter is better and if adding weight, it is added low on the chassis. The intent of the rule was to permit a wide variety of cars including the top heavy but more durable Carrera cars. In pre-race inspection bodies were removed and weighted separately.
In our LeMans races, most entrants built special cars for the event, many with considerable effort and testing. Various strategies were tried. Some ran conservative setups they could drive the distance non-stop without a crash, others knew that their faster cars might require pit stops to cool. Pits were stocked with spares and tools at the ready. Many drivers used electronic cooling spray, heat-sinks, ball bearings, air ducting and other trick set-ups or strategies.
One racer, Bill Liscomb a pilot, did careful development and testing. Months in advance, he stayed late after races, requested the track be turned up to 21 volts and tested various motors, gear ratios, bodies and chassis set ups. He eventually developed a car that could run non-stop with no crashes at a 2.8 second pace for the full hour; substantially better than the previous year’s record. He then built three fresh ones, each with a spare motor and other parts and entered all three, targeting a podium sweep. Other racers saw his set up as the benchmark and many copied it. We had 16 entries. Since Quadrophenia is a four lane track, there were 4 groups running one hour each. We did a qualifying session and slowest group ran first. Our pilot, Bill Liscomb, would drive all three of his cars, they had all qualified mid field, but since he could not drive more than one at a time, he started his first car with Group 1. 11 minutes into the first stint, his motor went up in smoke. Odd, we thought, no car with that set up had failed in testing… He put in a spare motor and 10 minutes later, more smoke. Another motor – same result. It was at that point we realized that all his testing had been done in the evening when the shop was 65 degrees and on race day it was almost 85. The ambient temperature had changed the race conditions! All of the Bill’s cars, including spares and most the copycats went up in smoke! Some of the failures were spectacular, one car caught fire, another had used hot glue to secure the motor and it liquified, at first causing cobwebs, then when the motor failed, it stuck the track like stubborn pizza cheese. Mildly tuned up NSR and Slot.it cars were hundreds of laps from being competitive or their bodies went to pieces, body posts were sheared off in crashes, several cars needed duct tape to continue, bent wheel and axles, broken guides, ground up gears, worn out tires, lots of frantic action in the pits, but only 7 of 16 cars finished… a true endurance event!
Panoz 1447 used less magnet than many others. Instead, it had very low center of gravity and a controversial interpretation of the rules that would be banned in future events. It used a heavy steel chassis and extremely light Lexan body. It skirted the body weight rule by attaching hinged lead panels to the body that laid flat on the chassis. This met the letter of the 45 gram body rule, but kept an extremely low CG. Also, the weights were free to move, thus damping vibration and improving cornering speed. Rather than a handicap, the weight was then used to advantage.
Horsepower for Panoz 1447 came from a Falcon 7 motor soldered into the steel chassis at several points so the chassis itself functioned as a heat-sink. The soldered steel pinion and 64 pitch bronze spur gear also drew heat directly from the armature. An aluminum heat-sink was added for good measure. The JK steel chassis does not normally have functioning front wheels, so an axle assembly was soldered in and very free rolling, independent o-ring wheels rolled to reduce guide friction. Wheel stickers on closed front wheel openings preserved both aerodynamic down-force and scale appearance. Rear wheel inserts were in place – now missing. A high-grade commercial guide was reinforced with a steel pin. The robust tied and silver soldered steel bumper at the rear is necessary to prevent wheel and axle damage in shunts. After all, the car corners faster that most people could throw it! As it is, the car suffered considerable body damage in its single one-hour event. Late in the race the rear magnets began to touch the track rails, the scarring can be seen in the photos. Since the car had adequate clearance at the beginning and end of the race, the problem was due to track rails being pulled upward by other extreme magnet cars. The car was not black flagged for the clearance problem as it was determined to be a track condition change. The resulting sparks were spectacular, but did not affect other cars performance.
This car needs to be driven well to stay on track at competitive speed. A Falcon 7 motor at 21 volts is a handful on any track! Unlike many slot cars with extra magnets, no corners could be driven flat out. Less magnet reduced motor stress, but increased driver and controller stress. Such concentration for a full hour is hard work! During the race, the car gradually became harder to drive with several hard shunts, At first, I suspected that body damage was creating aerodynamic lift and bottoming out due to rail lift, but as the problem got worse, I realized the transistor in my controller was overheating. Swapping to a back-up controller solved the problem. Near the end of the race, a tire came partially un-bonded from the rim and but was only a problem at the end of the straights, so I was able to bring it home.
This car won its one hour race with 1447 laps, thus the car’s nickname. Which means average lap time was 2.487 seconds INCLUDING crashes, pit stops, lane transitions and controller change. Its best lap time was 2.17 seconds. Production Carrera cars typically turn about 5 seconds per lap on Quadrophenia,which means Panoz 1447 was more than twice as fast, counting more than 2 laps for every one made by a standard car.
Although many drivers had fun at our LeMans races, it was the only race in which we allowed high magnet cars. (That is car that can hang on an inverted track section.) Generally, racing at such speed leads to damage, cost escalation and high drama. Faster is NOT more fun. As is true in full scale endurance races our format lead to as many as 70% DNFs. This form of racing is not for the casual racer, be warned… speed kills.
BTW: Panoz 1447 is not the fastest slot car to run on Quadrophenia, I have another custom built race winner “Doppleganger” that holds the single lap record at 1.863 seconds, but that is another story!