Charlie’s Funny Car

In the fall of 2000, Laurie T. called and said she was in a jam.   All the guys in her family are involved in one way or another in drag racing.   Her husband owns and operates a drag racing team, her 11 year old son drives a junior dragster, and her youngest, Charlie Joe is an avid fan of legendary funny car driver John Force.

Six year old Charlie had come to her and stated that Santa can make anything.   And he was sure that if she just asked, Santa could make a John Force funny car for him to drive.   Charlie has a number of battery powered ride-on trucks, so he’s no stranger to driving.   She tried to tell him that maybe some things were beyond even Santa, but he was not to be dissuaded.

Laurie wondered if I was interested in being an elf.  I love a challenge, and am a race fan myself, so I accepted the assignment.

The project began by surreptitiously making off with an old Power Wheels® truck that had been sitting around in the garage, unused for quite some time.   Of course the day after this long-forgotten toy came home with me, young Charlie was grilling his Mom about the whereabouts of his truck.

Funny Car 1Shown here it has been partially dissected in order to study the wiring and power system.   At first the wiring was baffling, seeming to double back upon itself.   But, with a good deal of help from my Father, who is good with electronics, we figured it out and I stripped the wiring, switches, batteries, motors, running gear and wheels from the old truck.

The next step was to download and study photos of John Force’s funny car and produce working drawings to map out the course ahead on paper.   My original thought was to build a scale model of the real funny car, with the wheel diameter setting the scale ratio.

Funny Car 2Unfortunately it wasn’t until I got the chassis layout and side view elevation all done that it occurred to me that there was a problem.

This “toy” is intended to be a Christmas present.   The weather around Christmas is often a bit unpredictable.   The T family has a large family room in which the boys often ride their large toys, but at almost 7 feet long, turning radius will be a problem for indoor use. So I re-designed it to be more of a caricature of a funny car, with a more reasonable size and turning radius for indoor use.

Funny Car 3The first stage of actual construction was to build a light weight but strong chassis.   My solution was to laminate up a frame work of 1¼” wide strips of ¼” baltic birch plywood.   By alternating strips that ran the full length with ones that ran full width, a strong, stable lattice was achieved.   Keeping it light weight is very important so that the battery powered motors won’t be overloaded by weight of car and passenger.

Funny Car 4 Once the chassis was ready, I added mounts for steering gear and the drive motors and rear axle.   The “shock towers” are probably over-built, but I’d prefer to make sure the steering gear can stand up to bumping along in the back yard without that sickening crack of a major suspension part giving up the ghost.   They’re braced fore & aft and cross braces will be installed as the ribbing is added in the nose section.   A compartment will be mounted between them to provide a secure yet easy to access place to keep the 6 volt batteries and their charger.

Funny Car 5 With most of the body ribs & stringers installed, I flipped the chassis over to ease installing the skirt supports and battery compartment belly pan and to give the under side a thorough coat of sealant to help protect it.   The baltic birch ply is quite weather resistant, but I prefer not to take chances.

I decided to use a skirt around the edge rather than setting the chassis that low to help with ground clearance.   This would not be a concern if it was used only indoors or on the driveway, but drag from grass and uneven ground could cause the motors to overload and trip the breaker.

Funny Car 6The body uses ribs and stringers like a model airplane to keep the weight to a minimum yet provide a rigid, sturdy frame for the skin.   1/4″ Baltic Birch Ply is used for all of these structures, with reinforcing blocks made from shop scraps — mostly poplar — where additional strength is needed.   The polyurethane glue assures great strength, but slows construction because all parts installed must be securely clamped for 12 hours while the glue catalyzes.

Funny Car-7One side effect of this glue is that it foams out of the joints as it sets up.   Once hardened, the foam trims away easily, but I must be vigilant and remove it anywhere it would interfere with the fit of other parts.

With the rear fender wells bent into place, dash board mounts and the firewall with it’s attendant accelerator pedal and wiring in place, it’s starting to come together.   Rather than running the wiring underneath the floor boards, I ran a length of 3/4″ dowel through the table saw to flatten an edge, then used a cove bit in the router table to hollow it out.   This tube runs from the fire wall to the rear wheels like a transmission hump and conceals the wires running to the motors on the rear wheels.

Funny Car-8With the dash installed, the switches can be wired and all systems tested before the body panels start going on.
My thanks to the Woltman Company for allowing me to use their sublimation equipment to produce the 4 nifty gauges used on the dash.

Funny Car-9. The steering gear from the original truck was installed backward so that the tie rod is behind the front wheels instead on in front.   This was necessary because this car is about a foot longer than the truck was.   I had hoped to bend the metal parts of the tie rod and steering rod and use the same direct connection used originally, but found that this would not work out.   Instead I elected to go with the cable system shown.   It’s more complex, but quite reliable.

Funny Car-11 The most complex curves are on the nose of the car.   So to deal with that, I constructed a hollow nose cone from layers of basswood.   Basswood is very light weight and easy to carve and shape.   I’ll use a rasp to rough out the shape, then sand with successively finer grits to make a smooth surface.

Funny Car-10 The interior panels have been painted and installed, Dash in place and all wiring secured, we are ready to start fitting body panels.

Funny Car-12 The neighbors thought I was crazy when I set up this “Witches Kettle” for steaming the plywood that will become the skin of the car.   Baltic birch becomes quite pliable if soaked in very hot water for about 15 minutes.   This is great for smaller pieces, like the wheel wells, but a problem with larger panels.   I wanted to keep the body panels as large as possible to maximize strength and minimize the number of joints to fill and fair.   I had hoped that by steaming the panel over the wash tub, I could get the desired effect.  Wrong!   With an air temperature in the mid 30°s the wood cooled far too fast.   I ended up bringing out all my shop rags and soaking them in the near boiling water, placing the soaking, steaming rags on the wood where I needed it to bend, then working with clamps to persuade it some.   It worked, but it wasn’t as easy as it should have been; one quarter panel took me all afternoon to fenagle into place and secure.   If I ever do this again, I’ll buy a horse trough.

Funny Car-13. After having a terrible time getting the rear quarter panel installed, I sawed the front quarter panel into smaller pieces — strips where the curves are trickiest — and installed them with many, many little screws instead of clamps.   Clamps would get in the way of installing the rest of the strips.   The 130 screws will be removed once the glue sets up hard.   Then the screw holes and seams between panels will be filled with automotive body putty, faired off, and the whole thing sanded smooth ready to paint.

Funny Car-14 With the body sanded smooth and a base coat of gloss white on, Elf #2 is called in to lend her artistic talents to the layout of the paint job.   She also had the foresight to bring along a die-cast model of the John Force car to serve as a pattern… MUCH easier to visualize than working with the pictures I downloaded from the internet.   Especially since no two of those had the same paint job!

Funny Car-15 Most of the paint is in place, and lettering is going on.   Now all that is needed is to produce many many little sponsor stickers to give it that ‘authentic’ look.   Also have to permanently install the super-charger and it’s air scoop, rear spoiler, and of course the seat.

Funny Car-21Of course everyone knows that dragsters don’t run knobby mud tires, which is what the original truck came with, so it was necessary to turn them into racing slicks.   This was accomplished with black silicone sealant and Styrofoam – used as a filler.  As it turns out, the wooden fender wells magnify and project the sound of the electric motors into a satisfyingly powerful growl as the car speeds around the family room.

Funny Car-16The finished product was a tremendous hit with the budding young racer and we are very happy to have been able to make Charlie’s Christmas so joyful.

Merry Christmas Charlie!