Body Style: 1998 Ford Taurus               Manufacturer: Revell/Monogram
Motor: Graupner Speed 280                  Speed controller: JETI 040
Rearend: LIVE NINE                         Rearend Gear Ratio: TOMY 3.57 (7T:25T .28)
Reciever: Hi Tech SHREDDER                 Steering Servo: HiTech HS-50

Mark Martin is truely one of the all time great stock car racers, and his number "6" Valvoline Special was a very attractive racer.

I wanted to build a NASCAR racer to show how the LIVE NINE rearend could be used to install Radio Control into a 1/25 NASCAR model. I selected a Revell model as my starting point. The building principles outlined here will apply to any of these models of NASCAR stockcars.

There are many parts in this kit and much painting is required to achieve an attractive model. Some parts are not used at all and some have to be modified to some extent.

I began by building the steerable front end.

Let's take a closer look!

Here's how the steering servo is mounted.

Next was to mount the Speed 280 electric motor. The floor of the chassis was modified with a drum sander on a Dremel tool. A motor mount was constructed from sheet styrene and cemented with Testor's cement. The mount was drilled to accept the motor shaft and mounting screw holes before it was fit to the chassis. A forward supporting member was fashioned from the same material to support the front of the motor. These two parts are reinforced with sheet stock running between them as per this picture.

The first battery installation I used had the batteries mounted in two AA battery holders from the Radio Shack. I used Dean's unpolarized connectors here because that's what I had, but I strongly recommend using polarized Dean's connectors, it eliminates all possibility of incorrect connection of power source.

However, this did not work well. Advancing the throttle past about 75% caused the speed controller to shut down! Either the battery holders were making intermittent contact or were not allowing enough current to flow. This is a microproccessor controlled speed control so any voltage less than about 4 volts will cause the controller to shut down the throttle ... but not the steering. This is a safety feature for aviation purposes.

I was able to overcome this problem by soldering 18 gauge wires directly to the battery poles. The differnce in performance was surprizing! ... and this time I used polarized connectors for safety. Now, the car really goes!!

The best way to solder these battery connections is to grind the battery poles lightly with your motor tool. I used the cut off discs to "rough up" the end ever so lightly to remove the surface plating on the battery poles. Also, getting sufficient temperature to the battery poles wasn't possible with my iron. So ... I "overheated" the tip of the iron with my propane torch and quickly soldered the connections. This worked well!

Here's how it fits into car. I'm using a JETI 04 speed controller because it allows operation on only four cells. Space is at a premium. Also, you can see the SHREDDER receiver sitting on the rear deck. This is a simple, small two channel receiver from HITEC.

Now let's look at the LIVE NINE rearend application. The face of the front casting is filed smooth to accept pulley and pump assembly from kit to add a little more realism. It worked out well. The dimensions of the axles and axle tubes are critical on this model because of the way the chassis covers the wheels and the body encloses the running gear.

My measurments are as follows:

Left axle
Left axle tube
right axle
Right axle tube
Pinion shaft
Pinion shaft tube

The method I used to secure the rearend to the bars was to simply bind them on with braided musky line.
A single wrap and a touch of CA is very secure, and can be removed with a hobby knife or single edge razor blade. I file a flat onto the bars and a small groove to locate the rearend. I pull the axle up tight with the thread, and touch it with glue from an applicator tip. This line is 28 lb. test line. It will not break! With CA it is STRONG! To remove it use a sharp blade to shave it off ... be careful!

This photo shows the rearend bound on with musky line and shows how the driveline is connected with small i.d. silicon tubing used for driveshaft connection.

Obtaining good results requires proper preparation, planning, and attention to detail. Good lighting is a must!
Clean dust free surface a requisite! And the self control not to touch it until it is thoroughly dry!
Figure out how you will support the model before you begin painting. You must be able to spray from all angles, and be able to view the surface of the wet paint inorder to achieve a glass like finish.

Inspect the body and remover any flash from windows and bottom edge with 600 grit wet-or-dry. Some modelers wash the shell in mild detergent water solution and rinse thoroughly with distilled water. Not a bad idea, but be sure the model is totally dry before trying to paint it. Even the smallest droplet of water will ruin the result.

I have used Testor's spray cans with good results. I find it settles nicely and dries fairly quickly, overnight is best.

For detailing the motor, painting the air dams and spoiler, I used Floquil model railroad paints. These also dry quickly and provide a flat finish for those areas that need it.

After your paint has dried for a couple of days and is safe to handle you can start decaling.
This model uses "water slide" decals. The decals are soaked in water until the desired image loosens and can be slid off onto the model's surface. Decaling cannot be hurried. It requires time for the water to release the decal. Trying to force the decal from the backing before it is ready to be removed will result in a torn decal. So, just relax, and let the water do its job.

I did my decaling in three one hour sessions. You could save time by painting the model's shell before actually building the car. This will allow you to soak and apply decals while you're working on the rest of the car. Also, you can start soaking decals at intervals of a few minutes apart to keep you ready with decals as you apply the first one immersed. I used a little Walther's SOLVASET but don't overdo it with this. Once the decal is ready to be slid from the backing paper I brush a little SOLVASET onto the area where the decal is to be applied. I find this allows the decal to settle a bit more snuggly. I think it could be thinned with water about 50:50. I burnish my decals with cotton tipped swabs after application to remove excess water, air bubbles, and to help straighten the decal. Be sure the decal is down totally before leaving it to dry, or you will get air under the decal.

Once you are satisfied with your decals, let them dry thoroughly for a day or two. Give the entire car shell and hood a coat of clear gloss and do not touch until it is thoroughly dry (24 hrs)!! Then give it another and let that dry too. If you want to your can apply a third coat if you think the decal's edges are still too prominent.

To calculate speed potential assume the motor is turning 5000 RPM (Revolution per Minute).

Multiply this by the reduction factor of the LIVE NINE rearend (.28); this gives a wheel rotation speed of 1400 RPM.

Next measure the wheel diameter and multiply by pi (3.14). My wheels measured 1.15 inches. This gives a wheel circumference of 3.611 inches. (Remember C=2pi*r or, pi*diameter).

Now, multiply wheel circumference times RPM ... 3.611*1400 = 5055.4 inches/minute. Next divide by 12 to get feet 5055.4/12 = 421.283 feet per minute.

next, multiply by 60 to get feet per hour 421.283*60 = 25,277 feet per hour.

Finally, divide feet per hour by 5280 feet per mile to get 4.78 MPH.

To get scale speed multiply times 25 ... or 119.7 MPH !!

This is a very fast walk! You will need a smooth surface to run this car. A gym floor would be ideal. Avoid sidewalk cracks!

There is enough "spurt" in this motor to do the victory donuts!

Copyright Robert Rydman 2004