Pinewood Derby Car Weight

Adding Pinewood Derby car weights is an important step when milliseconds count. Weight placement is important because you want the longest possible push time while balancing stability.  The further back you can move the weight distribution, the more energy your car stores, which in turn translates to more push down the track. Because there are MANY more factors involved making a pinewood derby car, there are many more articles to read. This article is only going to address WEIGHT.

ITEMS NEEDED:

  • Completed Painted car with wheels and axles to a weight of about 4.3 oz
  • Tungsten Putty (1 oz)
  • Ruler (attached to a base so that it is standing on its edge)
  • Digital scale measuring in .001 oz (these are rather inexpensive these days. Less than $10 shipped from Ebay)

This is no secret to seasoned builders. Pinewood Derby Car Weight placement plays an important role in how well a PWD car will perform. There are numerous scientific equations that will explain the science behind this. Simply put the more weight you can shift towards the rear of the car, the more “potential” energy it will have. The key important term his is POTENTIAL. It is believed that the more stored energy you have, the faster your car can travel. However, the PWD world has been proven that COG (center of gravity) is the more important than shoving all the weight in the rear of the car.

Center of Mass / Gravity Pinewood Derby Car

What is COG? It is an important function in building a pinewood derby car. COG is the balance point of your car. This will be measured by using the ruler. There is a COG tool on the market for those that like to spend a few extra $$$. I’ll update this once I find it again. WHY is COG important? Putting Pinewood Derby Car Weight randomly on your PWD car is not the key to getting the most out of your build. Center of gravity placement should be between 1/2-1″ IN FRONT of REAR axle. This is true for all wheel base types. Whether you are using a standard wheel base or an extended wheel base. This has been determined not by mathematical formula, but by the PWD junkies with thousands of builds underneath their belts.

Take notice on one particular detail. TYPE of Pinewood Derby Car Weight . It will not matter if your weight is lead or tungsten to achieve a fast car. Tungsten does not make a car faster per say, but it does allow more energy to be stored.  SO if you are on a budget and you have $24 to spend between tungsten weight or lighter wheels.  The wheels will make your car much faster than the tungsten weight.  If every car has the same wheels, the same axles, the car body and your car has tungsten your should be faster.

Why the hype for Tungsten Pinewood Derby Car Weight

What tungsten does is allow you to place more Pinewood Derby Car Weight in the same amount of space which will yield more energy if place it further to the rear.  For COG, Weight is Weight. The maximum weight is 5oz. COG does not care whether it is wood, steel, lead, or tungsten. Before spending all your available funds on just Pinewood Derby Car Weight, please understand this statement. FOR all my builds, I use lead as primary weight. Weight pocket (meaning how big a hole is drilled for lead) depends on car design. Small profiles will need larger pockets to offset their reduction in wood weight.  Using tungsten putty, you can fine tune our balance point.

If two car body builds are identical, one uses lead, one uses tungsten, the tungsten has an advantage if the wheels are the same.  If the car builds are the same, and one uses lighter wheels.

Whoever uses lighter wheels will have the advantage.

Yea those 6 grams taken off those wheels mean all the advantage in the world and will beat a Type of Pinewood Derby Car Weight any day of the week.

Where to make the Balance Point of Pinewood Derby Car Weights

This balancing point (COG) will differ from car to car due to design, type of weight, type of wood, etc. The first thought that comes to mind is that the most potential energy would be a weighted rear bumper. This will not give you the fastest car. (Actually this type of weight placement will give the car too much “push” and will cause your car to fishtail don the flat of the track. ) Putting the weight on the front, although gets you a slightly quicker start down the curve, does not prove to be the best weight placement for the remaining flat portion of the track. The closer to a 1/2″ COG (in front of rear axle), the more potential for a faster car. From my experience, the closer the COG to the rear of the car, the more time it will take to tune it to its fastest speeds.

For your first build, I suggest a 1″ COG. It will give you a more stable ride, will require less tuning time. This COG is good for wood tracks or tracks that are very uneven at the seams / section junctions.  For a preliminary run at things, cut out your body. Sand it to near final sanding. Drill out the holes for your Pinewood Derby Car Weight. If you are using the solid “plate” lead weights, it will be more difficult to distribute weight to obtain the proper COG.   I am a big fan of 1x 3/8″ hole drilled behind the rear axle, with 2x 3/8″ holes in front of the rear axle as close as you can get them. Then adding 1/4″ weights. If your build can accommodate 5/8″ holes, that would only require a hole in front of and behind the rear axle using 1/2″ weights.

Pinewood Derby Car Weight – Best place for weight for Pinewood derby car

Completely stuff the rear hole – Always!  This hole should always have the most amount of Pinewood Derby Car Weight.  It will yield a faster body design.  Next, take your scale, and then temporarily place the remaining weight on top of the car body.  Add whatever Pinewood Derby Car Weight to the scale to see what you have to work with.  Form there you can determine if you have enough pocket space to make things work.    For factory wheels, I suggest bringing the overall weight of the body to 125 grams of weight.  Just a little bit heavier 128 /129 grams for weight reduced wheels.

Next start the balancing game.  Take a ruler, attach it to some sort of base so that it can rest on edge side up. Mark the range of 1/2-1″ in front of rear axle of your completed car, then start the balancing game. Add Pinewood Derby Car Weight to the front two pockets until you can get your car to balance on its own within that range. Use your best judgement. Some builders even drill multiple holes in the bottom of the car and use a good chunk of tungsten putty for final adjustments.  By leaving the last ounce of “ballast” you can easily move the COG to the proper location. If you bring your car up to a higher weight, the less ballast material you have to adjust your COG.  So it is a true balance game that is unique to each build.  There are no wrong ways.

Congrats, you have now the knowledge on where to place your weight and how to get it adjusted so that you have the best advantage….

Need to know how to setup the rest of your car?  Read this thesis….

Once your COG is obtained, then the next step would be tuning your car. Click here for the NEWEST method that is making winners out of first time builders. Simple to see, simple to understand. No track needed.