Will adding a raised front end to your car help it get a head start?

One of the pieces of misguided advice I often see is to install a raised front end (often called a “cheater bar”) in the car. The theory behind the cheater bar is that when the gate drops, the top moves before the bottom, so if your car has a high front, it’s able to start moving before the other cars do.

It won’t help on any track that uses a spring-loaded starting gate.

While a raised front might be of some minimal benefit on a manually-operated gate that’s released slowly enough, on any gate that drops quickly, the entire gate will be clear the car before it is able to overcome inertia and start rolling. You might get a paper’s thickness of a head start, but not enough to make any real difference at the finish line.

Photo from Flickr user corben23

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Comments

5 comments so far ↓

• Mike // Feb 27, 2012 at 12:37 pm

  This is pretty funny to read. Most of the timers on the tracks read out x.xx, cars are weighed to the .1 of an oz. Axles are polished with 3000 grit sand paper and wheels are meticulously shaped. But here you are saying that a car having a .004-.008 inch advantages is pointless. It is not one thing that makes a winning car it a whole bunch of little things that add up together to make a winning car. That .004 head start could be the difference between winning and losing a race. But neither really matters all that matters is the look in my 7yr old sons face when he understood the physics behind why we were using the raised nose. So I can honestly say we have already won the race.

• Adam Kalsey // Feb 27, 2012 at 5:25 pm

  Unless you’re on track in which starting gates and finish line timers are precision-machined and laser-aligned, chances are that the cars on the track already have total race distances that vary much more than the narrow tolerances you’re talking about.

  Subtracting a thousandth of an inch off your run time doesn’t matter if your track is banged around, stored poorly, and assembled in a hurry using hand tools. Like most tracks.

  With a spring-loaded gate, the gate almost vanishes like magic. The length of time between when the top of the gate moves and the bottom of the gate moves is miniscule.

  Unless you have something sticky on the nose to cause the falling gate to propel the car forward (which is of course illegal), you’re gaining no race advantage from that raised nose on a track with a spring loaded gate. In fact, Maximum Velocity did extensive testing and found that the cheater bar car was no faster than the exact same car without the bar.

  I’d encourage you to take the testing a step further with your son. Use this to teach the scientific method. You have a hypothesis: that a raised nose car is faster. Create a test car with a variable-height nose and a test track that can be started with a manual or a spring gate. Find out if your theory is right, and under which conditions the car is faster.

  Teach your son the value of verifying your ideas instead of just believing what you read on the internet. That will be of more value than the physics lesson.

• Bill Klingler // Mar 1, 2012 at 2:51 am

  The car pictured was built using the wrong end for the front. Between two “Perfect” cars, the car pictured would lose every race. The 2 cars would look exactly the same but the CG on the car he was racing would be higher up the arc. This would give the advantage of higher velocity and more on the “Front End Extension” effect when the car goes through the curve. That is why we cut off 5/16″ from the back and move it to the front. It is also another reason we use Tungsten so we can position our CG where we want it. Don’t use the picture of the car on the BSA box as an example. It is wrong.

• Bill Klingler // Mar 1, 2012 at 3:06 am

  Mr. Adam Kalsey, you are a very kind man. I know this to be true by the way you answered this gentleman. Thank you.

• Mike // Mar 1, 2012 at 8:42 am

  Having just read the maximum velocity article it still does not prove that the raised front end does aid in getting a head start. The test they did was not done scientifically; it had too many variables, mainly 32 feet of track. In order to do a controlled test of the starting advantage you only need to a few millimeters of track. The extra 32 feet have too many variables that will influence the car, remember this method is only to get you a head start. It is just a small piece of the pie.
  Drawing a free body diagram for a spring loaded pin start it is easy to see the starting advantage. The advantage will be the difference in heights between your car and a lower car divided by the speed at which the pin drops. So let’s say the pins speed is 60 in/sec (I am just guessing here) and the height difference is 1 inch so in this example the advantage would be 1/60 seconds or .0166 seconds. I will agree that it is not much and there are more things to spend our time on for a faster car, but it is an advantage.
  I do agree with you, never read something on the internet and take it for fact, to include your website. (PS I did not learn about the raised front end on the internet) Publish an article in a scientific journal on the science of the pinewood derby and then I might not second guess you .
  I think it is honorable of you to share your knowledge of the pinewood derby.

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See also

• Longer wheelbases go faster
• Sometimes, weight goes in front
• Weight to the back
• Lubrication is important
• Three wheels are better