Project: Ultimate Stampede
Modifications: Phase I
I bought the Stampede as an unopened, ready to run package for $150 on eBay. As soon as I got it out of the box, the carnage began. Not a single milliamp of electricity was pushed through the stock, manual speed control (MSC) before it got the axe in favor of a Reactor reversible electronic (ESC) from Novak. This unit ended up being too weak for the application, and was replaced with a cheap, but extremely durable Tekin Rebel that turned out to be a perfect match for my needs.
Next to go were the stock hub carriers. In my experience with the Rustler, a full set of 5x8mm wheel ball bearings (direct replacements for the stock metal bushings) would last three heats, on average, before at least one would bust apart. RPM makes replacement carriers to hold virtually unbreakable 5x11mm BB's, and while ordering these I also picked up some bright yellow spring preload spacers, lower spring retainers, ESC mount and gear cover, all from the same company. True, the yellow stuff would never make the truck faster, but hey, it looked pretty and was dirt cheap!
First Test!
With these basic ammenities tended to, I dropped in a Trinity P2K we had laying around with stock gearing, glued some Mashers (original, not 2000) to the rims, borrowed the durable Proline Silverado body from my Rustler and headed out to the races to get a feel for this lil' monster. How fun it was! Surprisingly zesty for a stock-motored truck, she took home 2nd place in the open monster class out of a small field of only 4 or 5 trucks, but was lapped in the main by a well-tuned (but mostly stock), well-driven T-Maxx. Aside from having a good time, I learned a lot from this first run. The 'Pede would need a mod motor (uncharted territory for me) with a well-balanced power band to maintain good low-end torque while markedly increasing pickup in the upper 50% of its RPM range. Next, the center of gravity (CG) would have to be lowered significantly, for the truck gave the corner marshals somewhat of a workout. Also, though the steering servo did its job of turning the front wheels, the 'pede was pushing a lot in the turns (understeering). Finally, the old self-removing plastic shock cap nightmare had come back to haunt me; had to do something about that. Back to the shop...
More Modifications...
Taking a cue from stadium trucks (the Stampede's suspension is, after all, identical to the Rustler's), I made the front and rear arms level by installing some spare Rustler front springs on the rears with preload spacers and Losi dark green springs on the front. While I had the rear shocks off, I put on some Traxxas teflon-coated aluminum shock caps that wouldn't come off on their own after filling the cylinders with Associated 50wt oil. I also put on a Nitro Stampede shock tower (stock plastic version), which is a bit stiffer with a molded-in cross-brace at the top. For torque, I put in a 17-turn triple-wind Trinity D3.5 mod motor (later to be replaced by an even stronger 14-turn double Speed Gem "Onyx"). To decrease the truck's unsprung weight and rotating mass, I cut out a new set of Traxxas nylon rims as shown below (using front, deep-offset rims on the rear for a wider stance), adding a little "cool" factor in the process! For more side bite and cornering ability, I switched to the then new Proline Masher 2000's and did some Dremel work on the fronts, adding a third axial groove, horizontally splitting each center diamond-shaped treadpiece, and bevelling the outer edge. The new, softer front springs would also help in the turns by letting the truck transfer more weight forward and down under deceleration.
To help reduce unsprung and overall weight, I made some gaping chassis holes, removing some truly unneeded plastic, removed the upper portion of the motor shield that is molded into the left transmission half (allowing us to later install a hefty Trinity heatsink), and significantly shaved down all four a-arms in the pattern developed for our Rustler. While reinstalling the rear a-arms, I mounted each to the lower hole on its respective hub carrier and moved the inside camber link mount to its upper hole to keep the geometry correct. This made the driveshafts close to parallel with the a-arms and the ground, minimizing strain on the half-shaft u-joints for minimal torque loss.
Mission Accomplished!
With the standard-fare replacements of motor, speed control and tires, plus about $35 worth of "hop-ups" (about half of which being just for show) and some Dremel work, my originally box-stock Stampede had become a stable, smooth-running, speed-happy racer. Now go check out Phase II!
