Mike Johnson Racing Tip

132 days ago by St. Louis

Radius equals Speed

So, you want to go faster at Pole Position Raceway.  You see the low times that the track guys put up and figure they must be running the hot kart or have some other secret advantage.  Well, one secret that I have been teaching for over 20 years is radius equals speed. OK, so maybe it's not a secret since it's an actual mathematical equation, but if you get your brain to understand it, you'll go faster.  The equation is simple, the bigger the radius, the bigger the speed, and of course the smaller the radius, the smaller the speed.  Think of a record (remember those?) going around and around.  If you put a mark at the outside of the record and another one on the inside, then spin the record, which mark will make a full revolution quicker?  Well, the mark on the inside has the shortest distance, so it should get around quicker.  But the mark on the outside is going faster, so it should go around quicker.  Most of you should know that they will get around at the exact same time because no matter where you are, 1 revolution is 1 revolution.  You can go a shorter distance slow, or a long distance fast, but either way, you get around at the same time, and in racing, speed and distance don't count, lap time does.

So, how do you translate that on the race track.  Simple, if you want to go faster you have to increase your radius.  That means when you are exiting the corner, and applying the gas, you need to open your hands and straighten the wheel.  Think about it.  If you apply the gas, with the wheel turned, you can not go faster, since you are not increaasing the radius.  All you are doing, is creating understeer.   This equation also applys to braking.  You can not brake and turn at the same time, especially with any speed, or you will spin.  But, while you are braking and reducing speed, you can turn, (called trail-braking) and decrease your radius.  If you do it properly, your speed and radius will decrease as you go into the corner, your radius and speed will remain constant through the corner, then your radius and speed will increase coming off the corner.  Racing is not about speed, it's about accleration.  In drag, road and oval racing, top speed doesn't win, the time it takes to get to point A to point B does.  So, the only way to accelerate (increasing speed) is to have the largest radius possible.  

Hope that helps and we'll see you on the track.