Scaling Up: Design a Pinewood Derby Car from a Toy Car

I generally build pinewood derby ‘cars’ that don’t look like real cars. Oftentimes it is awkward to coerce a real car design into the pinewood derby car form factor. However, many people like to use a real car as the basis for a design, and in fact, I have done so a few times. So in this article I will explain how this conversion is accomplished, and the design decisions that will need to be made. Although I will focus on scaling up from a toy car, the same principles apply when scaling down from a full-size car.


When building models, the ‘scale’ refers to the size of the model relative to the original. For example, many people have heard of ‘HO Scale’, a popular scale for model railroading. The HO scale is 1:87. That is, for every 1 inch in length (also width and height) of the model, the real train is 87 inches. Thus a train car that measures 44 feet long would be a little over 6 inches long in HO scale (44 feet, times 12 inches per foot, divided by 87).

Pinewood Derby Cars do not have a specific scale factor, as they are forced to be 7 inches long by 1-3/4 inches wide (instead of varying in size based on the size of the original). For many standard automobile sizes, 1:24 is pretty close, and in fact 1:24 scale decals generally work pretty well. However, the scale would be reduced when modeling a compact car, while the scale would be increased when modeling a large vehicle. So, instead of using a specific scale the designer must calculate a scale factor for the given original.


To determine the scale, measure the length of the original vehicle, and then divide that number into 7 (inches). For example, let’s consider modeling a toy car that measures 3 inches long, 3/4 of an inch wide (excluding wheel wells), and 11/16 of an inch tall (see Figure 1). With these measurements, dividing the length (3) into 7 gives 2.33(1). Thus, for every 1 inch dimension of the toy car, the pinewood derby car will be 2.33 inches. Therefore, the pinewood derby car will be 7 inches long (2.33 times 3), 1-3/4 inches wide (2.33 times 3/4), and 1.6 inches tall (2.33 times 11/16). All other dimensions, such as the placement of the cockpit and engine, the location of the body curves, etc. are calculated using the same scale factor.

Figure 1 – Hot Wheels Sweet 16 II

At this point, a tradeoff may need to be made. In this case, the width is fine, however, 1.6 inches is quite tall for a pinewood derby car. If realism is the primary goal, then maintaining the 1.6 inches is okay. However, if speed is the primary goal, then it is best to reduce the height of the car as much as possible.

If the width is too narrow, then it would need to be arbitrarily increased to 1-3/4 inches. If the width is too wide, then two options exist:

– Arbitrarily reduce the width to 1-3/4 inches, slightly skewing the final car.
– Recalculate the scale factor based on the width instead of the length. This will result in a pinewood derby car that is shorter than 7 inches; however, the proportions of the toy car would be maintained.


The next design issue that must be resolved is the wheelbase. When the wheelbase of the toy car is scaled up, almost certainly it will not match the wheelbase required by your local rules. For example, on the toy car in Figure 1, using the 2.33 scale factor, the front wheels would be 0.73 inch from the front of the car, and 1.16 inches from the rear of the car. Obviously this does not match the BSA wheelbase (nor any other for that matter). At this point, the following options could be implemented (based on the rules for your race).

1. If your race rules require a wheelbase distance AND a wheelbase position, then adjust the wheelbase to meet the regulations. This will certainly skew the resulting car, but there isn’t really a choice in this case.

2. If your race rules require a wheelbase distance, but does not require a relative location then adjust the wheelbase to meet the required distance, but position the resulting wheelbase as close as possible to the position calculated with the scale factor. The resulting car will be skewed, but less so than in option 1.

3. If your race rules do not specify a wheelbase, then use the wheelbase calculated with the scale factor.


Another design issue is that of wheel wells. Many toy cars have wheel wells, so to accurately model the car the wheel wells must be included. This will require the addition of material to the sides of the car, followed by shaping the wheel wells to accommodate the pinewood derby wheels.

But wait; now we may have another issue. Measure the diameter of the wheels on the toy car, and then multiply the diameter by the scaling factor. Does the result closely match the diameter of a pinewood derby wheel? If not, the wheel wells will need to be adjusted to fit the pinewood derby wheels, which could skew the car.

Figure 2 – Hot Wheels Silver Bullet

As an example, for the car in Figure 2 (which also has a 2.33 scale factor), the rear wheels scale up to 1.16, but the front wheels scale up to 1.02. Since the standard BSA Speed is about 1.18, the wheel wells (mainly the front wheel wells) would need to be increased in size to accommodate the pinewood derby wheels.


When choosing a car to scale, you will need to consider the following factors before doing any wood working:

1. Given the rules for the local race, when the toy car is made to fit within the required dimensions, will it maintain the ‘look’ of the original toy? With strict wheelbase rules, try to find a toy car that will fit well within the local wheel base restrictions.

2. If you don’t want to deal with wheel wells, choose a car without them.

3. Make sure to consider car weighting. You will likely need to add 2 to 3 ounces of weight, so space must be available on the car to accommodate the weight.

4. Some toy cars are quite complex. Consider whether the car can be built with your tools, or whether the design can be simplified without sacrificing the original look.

5. Actually, if you have a young boy like mine, the most difficult problem will be finding a toy car that is still intact!


Here are three examples of modeled cars:

This Humvee in Figure 3 was modeled from a drawing on the internet. To model the wheelbase as accurately as possible, and to meet the BSA wheelbase specification, the car was shortened to 6.2 inches (see Figure 4 – blue lines show original body location, red lines show shortened location). The result is a wheelbase that matches the BSA wheelbase length, but is moved slightly forward from the standard location.

The body is made from three parts (you can see the glue lines running front to back). Before the parts were glued together, much of the middle part was cut away to eliminate weight. Even so, the final car required little to no added weight.

Figure 3 – Humvee Body

Figure 4 – Humvee Drawing Showing Shortened Body

Hot Wheels Car
This race car was modeled by a customer (see Figure 5). As you can see, the wheelbase was lengthened, the wheel wells were enlarged, but the general look was maintained.

Figure 5 – Hotwheels Car

Stock Car

This (unfinished) Stock Car body is for sale on our web site. The wheel base is lengthened to match the BSA wheelbase, but is offset to maintain the NASCAR look. The height of the car is slightly lowered (looks slightly mashed, but not overly so). 1:24 scale decals are used, but they had to be trimmed slightly as the actual scale factor is slightly larger than 1:24.

Figure 6 – Stock Car


If you need inspiration for a pinewood derby car design, your child’s toy box (or the local toy store) can provide a lot of great ideas. Then, by calculating a scale factor, creating a pinewood derby car from the toy car is not as hard as it may first appear. Just make sure to consider the overall dimensions, the wheelbase, wheel wells, and the overall complexity of the design before making any sawdust.

(1) Most ‘Hot Wheels’ brand cars are 3 inches long, resulting in a 2.33 scale factor.

From Pinewood Derby Times Volume 6, Issue 12

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Pinewood Derby Memory – Never too Late to Start

This was my first pinewood derby as a Dad. Due to lots of time constraints (Christmas break, where we went out of town, a science fair project for school that had concurrent preparatory time as the as pinewood derby, life in general, etc.) we started way too late, like the Thursday before the race. About the only thing that saved the day was that I had the forethought to subscribe to the Maximum Velocity newsletter in November!

Anyway, when installing the weights I accidentally splintered the wood severely, enough that it was beyond repair. Luckily, my son had selected a wedge-shaped car and still had enough wood to make another car out of the other half of the wood block. Obviously, the axle slots were not cut, but we went ahead anyway. My son sanded, painted, and put the pin stripes on the car. Then he helped polish the axles and wheels. We didn’t wet sand as my wife had already thought that I had gone “Down and Derby”, and I didn’t need to give her any more fuel for that fire! I hand drilled the axle holes, which I know is blasphemous, but it was my only choice. We lubricated with McLube Sailkote, since I had some for my sailboat. The wheels spun for a long time. After a rough alignment check we were ready.

At the weigh-in we started heavy, but got it down to 5.0 ounces. Since we had started so late I really had no hope, especially since there were no local rules published, and I saw lots of kit cars and speed wheels (no outlaw wheels, however) among the entrants.

After the first heat, my son and I got hopeful. As the heats wore on, and his friends slowly got eliminated, he got more excited. We made it to the 5th heat, where there were only 6 cars competing, before we were eliminated. So, out of 31 entrants, my son was tied for 5th. He was a little disappointed, but still very happy to have finished where he did.

Next year, we’re starting earlier; and we are buying the Pro-Body Tool!!

Christopher Brown

From Pinewood Derby Times Volume 6, Issue 11

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Pinewood Derby Car Showcase – September 20, 2013


Hot Dog – Ron Bosma

I have 2 boys who have since grown out of Cub Scouts and the pinewood derby. But for several years our family looked foreword to our annual fun. We couldn’t build just 2 cars; we also had to build one each for my wife and I. This helped me get over the urge to help Alex and Greg too much with their creations.

Another leader and I always had a fun race after the boys were through. The pack would challenge each other and us until it was time to leave. Over the years we got better and better thanks to your newsletter, tools, and tips. Throughout the years we have built race cars, space shuttles, a dog car, a porcupine, and even a shark. With this hot dog car I ignored aerodynamics altogether to get a fun design. It wasn’t the fastest car that year, but the kids loved it and it ran respectable times. We have a lot of great pinewood derby memories and still really enjoy reading about other peoples experiences in the Pinewood Derby Times. Thanks Maximum Velocity!

Scooby-Doo – Kyle McInerney

This is my son’s second year Pinewood derby car. He was into Scooby-Doo more than anything. Scooby won best design and 4th out of 10 Tigers. It may not have been the fastest, but to my son it’s the best car ever.

Speeder – Bob Drag

In 2006, Glenn’s (my son’s) car placed 3rd out of 29 Tigers. This year, I asked him what his goal would be – looks or speed. He enthusiastically chose speed – he didn’t really care whether it looked good! So after researching car designs he fell in love with the look of ‘The Speeder’. After numerous hours of prep work, sanding the body, axle polishing, wheel prep, and weight placement to find the optimum center of gravity – that required all of Dad’s patience – we got the car put together. At the Pack race Glenn’s car placed 1st out of 21 Wolves, and the icing on the cake was that he also won 1st Place for the Best Car Design. Now, we’re off to the Council races!

From Pinewood Derby Times Volume 6, Issue 11

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New Pinewood Derby Products from Maximum Velocity

Dear Fellow Pinewood Derby Enthusiast,

It was a hot summer, but finally the weather is cooling down. That means it is time to tell you about our hot new pinewood derby products. You can see all of our new products by clicking Here.

Here are a few highlights:

New Car Kits: We have introduced three new pinewood derby car kits: the Vector, the Barracuda, and the Funny Car. The Vector is designed around our Triangular Tungsten Canopy, and is built for speed. The Barracuda is a futuristic car with a plastic canopy and sleek curves. Finally, the Funny Car is a limited edition dragster – get one before
they are gone.

Aero Fenders: Fenders are all the rage, and for good reason; they do improve car performance. We offer front and back laser cut fenders in both pine and balsa.

Paint Stencils: I’m sure you’ve seen cars with really cool paint designs, and maybe you have wondered how they were done. Well now you can do it yourself with these high-quality paint stencils (also known as paint masks).

In addition, we also now carry acrylic paint, new decals and COG Tungsten Weights.

You can see all of our new products Here

== A Gift For You ==
To thank you for your continued patronage, we have a gift just for you. To receive a free ounce of 3/16 Tungsten Cubes, please add them to your shopping cart Here
This free gift is available through September 24, 2013.

In addition to the gift, you can get 10% off on your order. Just use coupon code:
on the final checkout page. This discount code is good through October 01, 2013.

== Inventory Clearance ==
We also are clearing inventory on several items including our Propeller Car Kit II, the Assimilator Kit (with a tungsten canopy), plastic car canopies, and paint markers. We don’t have many left, so don’t delay. Click Here to find our clearance items:

As always if we can help in any way, please contact us by e-mail at:

Best wishes to you and your family for a great pinewood derby racing season.

With best regards,
Randy Davis
Maximum Velocity – Give Your Car The Racer’s Edge!


Pinewood Derby Memory – You Never Know

My Son, Zachary is now a Webelo 1. We have been racing Pinewood Derby in our Pack since he was a Tiger. His first race was a heart breaker to say the least. His car came in third out of three cars! But, he got to go on to the District race because the top three from each Den gets to go.

The car was a disaster from the beginning. We used a standard Cub Scout block, and I just about cut off a finger trying to work on it! We had the wrong kind of paint, and had to put it on the stove to get the paint to dry, since we didn’t get it finished till the night before the race.

Before the District race, we had some more time to work on it. Well, the extra work didn’t do anything but make it run slower. It barely made it to the finish line! We were both heart broken, and he looked at me as if to say, “What happened former Cub Scout, Eagle Scout, now Den Leader?” I just told him that we learned from our mistakes, and we would work harder next year.

The next year he was a Wolf. This year we bought a kit instead of using the Cub Scout block, but we used the official BSA wheels from the official kit. We put the weight inside the car, which was a rail type. The night before the race while we where helping set up the track it ran fantastic! But the day of the race, we found out it was way too light. So, we added weight to the back. Well again, he came in last. I believe that adding the extra weight at the last minute threw off the balance of the car. I had put it towards the back.

So last year, we went with the rail type kit again. But instead of putting the weight inside, we got the weights that go across the full bottom of the car. I took a few off just in case it was over weight, but could add on at the last minute if need be. It came in at 5 oz. exactly.

Needless to say, he came in first in his Den, and third in the Pack. Then third in the District race a few weeks later. We where both very happy campers after that.

Funny thing is, the Cub who came in first in the Pack had hardly done any work on his car. He stood at the weigh-in putting washer’s on his car until it got to 5 ounces. Then he taped them on with masking tape!!! He didn’t place at District, but still! Like I told my son, it just goes to show you, you just never know how your car is going to run.

Our Pack race is going to be at the end of January this year. We are again going with the rail-type. I’ll let you know how we do!

Don Hoard
Cubmaster, Pack 202 in Greenbelt, Maryland

From Pinewood Derby Times Volume 6, Issue 10

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Pinewood Derby Car Showcase – September 4, 2013

Pinewood Derby Car Showcase

SpongeBob – Don Jones

This is the car I made for the adult race. He is made with a real sponge. Although he wasn’t a winner he was a kid favorite!

Twins – Butch Weathers

In my son Jack’s first year in the pinewood derby I cut out two cars so we could build them together (his car is the red one). I showed him what to do on mine, and he did the same to his. His attention span was quite short at times, so I helped him complete some tasks. I think there are three different layers of paint because he kept changing his mind about the color. When race day came, he was ecstatic; his car came in first out of all the Tigers. Here in Bergen County, New Jersey, the Tigers have their own race in the Regionals. We had a bit of a problem here because the Regionals require that all four wheels touch the ground. So we had to fill in the axle hole and drill a new one. We made the change, and his car went on to win the Regionals. Something that surprised me was how much faster my car was than his. We used my car as the prototype, and used the best wheels and axles on his car. The wheels on my car were a lot sloppier on the axles than his, they wobbled a lot when spun. We didn’t have a test track, so we didn’t find out my car was faster until I raced his after the derby was over.

Tank – Jon Joslin

My son Tommy and I have been working on our first Awana car since our Christmas break. I ordered your booklet of suggestions for making a derby car in early December, then I ordered several of your speed products. Tommy wanted to paint the car ‘camo’ colors, so we decided on the tank design. Being our first project, we have spent many hours already, and still have a ways to go. Melting and pouring lead into holes in the back of the car has been the most challenging part, but we were successful in obtaining 5.03 oz on an electronic balance with the COG about 1.75″ in front of the back axle. Our derby is in February, so we still have time to polish and lubricate the axles, and go through the alignment process. We are looking forward to the final event in February, and have already started making plans for next year’s design.

Editor’s Note: We strongly recommend not melting lead, as it is a potentially dangerous practice.

From Pinewood Derby Times Volume 6, Issue 10

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(C)2013, Maximum Velocity, Inc. All rights reserved.

Maximum Velocity Pinewood Derby Car Plans and Supplies