One of the first things that I did was changing the wheels. I substituted the balloon style tires for the street style tires. I also made the rear wheels larger to give more of a hot rod look. I wanted to maintain the stock functions as much as possible. This meant keeping the working model engine block, dimensions, and body. I pretty much resided myself to taking the driver's area apart to cram in the necessarily parts. I removed the seats, and placed a Power Functions battery box in the driver's area. I wasn't quite able to get the geometry compact enough to get the battery box fully inside the area. This meant that I had to remove the roof.
I then used the existing steering system including the front steering assemblies and the shaft which is used to move the steering by hand. I added a Power Functions medium motor with a worm-gear assembly that uses the white 24 tooth slip gear to actuate the steering. This not only allows for the steering to be precise and controllable, but also lets the motor try overrun the steering boundaries without causing any damage. This is important because kids do not seem to observe common sense with playing with other people's stuff.
While I was at it, I also put the Power Functions IR Receiver in the rear of the model. It fits quite nicely back there and helps the steering motor stay snug against the frame. I had to do a little bit of mechanical acrobatics to actually connect the receiver to the vehicle because the Technic holes ended up being spaced half off.
Given that I want to preserve the engine block reciprocation, I had to also preserve the shaft that connected the crankshaft to the wheels. Other than redesigning huge chunks of the model, preserving the shaft was the only real option. I searched for ways to finagle motors in at right angles, but nothing was quite fitting as well as I really wanted. Finally, I saw the KISS solution which was mounting another medium motor directly to the back of the frame which held the differential. It was much easier than doing any other solution and also preserved the frame and body. I am pretty happy with how this turned out:
|Right Side View|
|Left Side View|