This would be a very new and interesting challenge for me, taking something that's so advanced in stock form and still somehow pulling off a transformation that would leave me with a sense of accomplishment.
Because the XXX-T is so close to the ROAR dimension limits, the rules were going to be a problem. How did that translate in my mind? Frack the rules. What about looks? When the Matt Francis Edition first came out, the hot red accents made for a very welcome change from the "blue is better" status quo. However, by the time half the trucks at every race were lining up with cherry-colored wheels & rod ends, the novelty had worn off. Frack the red stuff. And for power? Mmm. Power. Power is good. Lots of power. That's right. Frack the nitro guys.
Luckily the XXX-T MFE came as a kit, so I didn't have to completely tear up beautiful prebuilt truck. Instead of playing experimental R&D while replacing different parts, I got to work on the final product right from the start. I completely subverted the original color scheme, opting instead for a strong green & aqua motif. Now there's something you don't see a lot of in RC. The shock bushings, ball ends, battery strap, front bumper (re-drilled), and wheels I chose were DuraTrax Evader ST upgrade parts. The Evader ball ends are metric, so I also had to swap out all of the ball studs. The MFE motor guard was replaced with a basic black unit. The stock (red, bad) 86-tooth spur gear was ditched in favor of an 88-tooth yellowish-green (greenish = good) replacement both for looks and to help move towards a taller gear ratio to handle a nice high-powered motor. Finally, a Trinity Kinwald edition lightweight light-blue (close enough to aqua, it's cool) motor plate was installed and I also used many pieces from the Trinity light blue aluminum screw kit as accents. Aluminum hardware is weak, so I had to exercise moderation with this last part.
 |
 |
 |
The most fundamental deviation from the stock form of the vehicle would be the installation of Duratrax Evader front a-arms both for added crash survivability (DTX plastic arms flex when impacted) and a ROAR-busting increase in width. Though the Evader arms are a good deal longer than the XXX-T's stockers, Evader front wheels I used have a slightly shallower offset than the stock Losi rims (i.e. the Evader rims they make the whole thing narrower). The result is a width of 13 1/4" versus the stock 12 7/16". At the rear, the use of Evader rear wheels widened the aft end out just past 13". For treads, I used the stock ribs up front and Pro-Line Lug Nuts on back.
With the rolling chassis looking pretty complete, it was time to breathe a bit of life into the little dragon. With a delightfully quick bit of mounting and soldering, the a full brushless motor system was installed. The controller is a Schulze 18.61co (non-BEC), and the motor I chose is a lightweight Lehner Basic 5300, just slightly smaller than most 540 brushed motors. To avoid having to use a receiver pack, I picked up an external "Ultimate" BEC unit from Kool Flight Systems. With ground temperatures reaching 140 degrees F in the middle of the summer, controller heat was going to be a problem. So, I bought a 12V fan and strapped it to the top of the controller. With the addition of my prized Airtronics 94257 ultrahigh-speed servo, the beast was ready to roll. Or was it? Not without a body it wasn't!
 |
 |
I looked at every 1/10th scale truck body I could find that had been made in the past 10 years, and not one of them provoked any sort of emotional response. I needed something different. Something memorable. A stock XXX buggy body would do just the trick. Mounting it was a slight challenge due to the longer truck chassis, but it worked out in the end.
 |
The final aesthetic touches would be green zip ties, a green center wire between the controller and motor, green front springs, green rear shock socks, a green antenna tube with green fuel tubing snippets to hold down the extra length of green Airtronics antenna wire, and anodized aqua blue body pins. Behold, one strange-looking R/C car.
|
Out on the track, my initial guess at gearing seemed good and I was able to hit top RPM's in about 2 seconds, the front wheels barely gliding over the surface as I badly out-accelerated the nitro trucks I had entered against. The bizarre vehicle felt like the shadow of a spider going around the track, it was so low and spindly. The best part of running it as hearing the comments of the local veteran drivers. They were quite puzzled, but really not surprised, given who they were dealing with. "JANG, what have you done this time?"
To test the beast's raw speed I put my Garmin eTrex GPS device to use for the first time strapped to the top of battery hold-down, for some precise measurements on an open asphalt lot. On its 7th run, bumped up to 22/88 gearing, running an Integy Sanyo 3300mah pack that had been charged the day before and not re-peaked, it registered 40.3mph. Mind you this was lugging around the 0.38lb GPS unit and running on 6 cells. The motor is rated for 10 cells. You do the math!
This was a very fun project that gave me a lot of insight into the running & tuning of a competition-class R/C, many notches in quality above what I'd worked with before. Look for more along these lines in future UltimateRC.com and URC Network projects!
 |
 |
 |