The Lego Ferrari F40 project went further and better than I had imagined it could. The model looks fantastic, and my Lego skills much improved, but what it needed to be complete was a proper wheelset to match the early-mid-1990's racecar spec.

Working on an idea for long 'tusks' on the nose of the rXA, I realized I might be able do away with the entire standard Traxxas front bumper and mounting assembly and replace it with a bracket and beam setup (similar to the latest LMP wing mount).

To take full advantage of aerodynamic downforce, the chassis needs to provide a rigid foundation for the wing to act on. Previous iterations of my wing mount were prone to flexing. Throw in a crash or two and they would eventually fail entirely.

The cardboard stock I use is perfect for prototyping parts. It's very stiff and nearly the same thickness as 2mm Stratocore, and it's cheap (well, free with purchase of Bisquick from Costco).

Toward the end of the GTP and Group C era, the quest for downforce lead some teams to a double-wing setup. Jaguar, Toyota, Joest, Peugeot and many others ran short tails and double wings, usually with massive endplates. The large lower wing was just off the trailing edge of the deck and effectively functioned as an extension of the underbody diffuser tunnel system, while the upper wings tended to be more compact and run at shallower, less-drag-inducing angles.

All the cardboard experimentation I do is leading up to a set of design templates to be used for constructing the final Stratocore components.

Test-build of the preliminary tunnel underfloor design. The Traxxas battery boxes angle up from a central low point on the underside of the chassis, so they leave some room for underfloor tunnels that the flat floor wasn't utilizing. The outlet end of the floor, and the rear diffuser, run at about the wheel/axle centerline. Aggressive, but effective...

After building a prototype of the twin-goose-neck rear wing and diffuser setup, it looked like it could develop even further. Also, the flat floor left quite a bit of unused room under the battery boxes which could be utilized for underfloor tunnels.

Running a very low, dynamically-loaded chassis requires precise spring and damping rates. However, the Traxxas chassis is optimized for off-road use with provisions for very long-travel suspension. Unfortunately this bias is exactly the opposite from what would be ideal for road use. In stock configuration, the front wheel rate to shock rate ratio is nearly 2:1, allowing a compact shock to take up a very long-travel load from the wheel.

Having addressed most of the problems small rocks pose to running the Rally in the dirt, the car would run long enough to expose yet another issue. When running in decomposed granite with its tiny granules , I noticed my steering block would eventually lock up.

I had a custom chassis-mount light kit built for me by Alpat Tugay via eBay. The whole rig is designed as a self-contained modular layer that fits onto the chassis without any tools or parts modifications. I wanted to be able to easily install the kit for occasional night runs, but leave it off and out of the way for daytime running.

One more area to address in the pursuit of saving center drives. There's a gaping point of access for rocks and things lurking under the motor. One would think there's too little room here to do much, but turns out there's plenty of space.

As my skills improve and car speeds increase, the little Traxxas Rally's instability at speed is becoming an issue. The chassis handles so much better without the bodywork on that I believe it's probably more than just a weight consideration.

My Rally has ground to a halt each time it's been run in decomposed granite or soft dirt. Opening up the underside reveals little rocks and other pulverized stuff getting in through various openings in the underbelly skid and under the motor.