One of the aspects of Thunderjet performance that has always been a little mystifying to me is the issue of the resistance rating of the motors. The idea behind this, and why it is important, is braking ability; when you let off the power, you want your car to slow, not stop; so you want this reduction of power to be a gradual effect; what you don’t want is a car that won’t slow down enough to negotiate a turn until you have to let off the power completely, causing it to stop; that’s no fun at all, and its not a bit realistic, so braking is as important as acceleration and speed when it comes to winning races!
Broaching this topic is a little painful these days, as it again makes me think about the loss of my great friend Dale, who was an electrician and knew more than I ever will about electricity and its characteristics. This hobby just isn’t the same without him, but I’m always trying to learn more and become a better “slottist,” so, on a fine sunny Saturday I decided to get out my old electrical meter and do some testing on some of my motors. What I found hasn’t cleared things up much!
The cars that represent the bulk of my collection, the Auto World Ultra G chassis that I race on “Drag City Raceway,” my big track, are marvelously consistent in their resistance ratings: I tested over half a dozen of them ranging in age from the early 2000’s when they were marketed as “Johnny Lighting Thunderjet 500’s” and made with the Playing Mantis imprint, to some of the brand new ones sold with the “Round 2” name, and found almost all of them within fractions of 14.5 ohms.
The older cars, however, were all over the place! They ranged from between 14-20 ohms for some of the oldest ones to as little as 6 ohms for the “Wildones” and “Tuff Ones”-era chassis. That’s not too surprising considering what I’ve read and learned, and you can find some great information about this topic online if you do a little digital digging. But when it comes to where the rubber meets the road (literally), the results of this information seem a lot less clear than what the numbers on the meter indicate.
So, here’s a demo of this concept showing several cars from my collection, how their motors tested, and what the results were on the track!
What’s confusing to me is that other slot racers seem to be all over the place as well, with some claiming you get more performance from lower resistance, while others say the opposite. So, which is it? Well, as with so many other aspects of slot car performance, it depends! There’s a lot of variables that go into this, and a lot of them seem more important than the resistance rating of the motor! That’s an aspect of it, but building your ultimate car is a lot more complex that just picking a low or high resistance motor! Compare the results in this video to your own experiences and tell me what you think!