For Team Associated fans around the world, the past few years have been pretty tough. Associated archrival Team Losi has been scoring big wins on the track and in the press with their XXX series of vehicles, while the RC10 series hasn't had a major electric off-road platform update since way back in '97.
Well, as of this writing, all of that is changing. 2003 will likely go down in the R/C history books as the year of the great Associated comeback. Already we've seen the release of the new L4 oval racer. In this article, I take a close look at the new-from-the-ground-up RC10 B4 electric buggy. Coming soon will be the T4 electric truck, followed by the Monster GT .21-powered nitro truck and who knows what else! It's a busy year for the A team!
Certainly the very first thing to notice about the B4 is the picture on the box. The car is sleek and low like no other offroad vehicle. More on that later, though. I received my B4 as a production "Team" kit, so assembly was the main order of the day.
The parts came in the usual sequentially-lettered bags, but though these filled up the box, most of the bulk seemed to be the plastic of the bags, themselves. The actual number of parts within them seemed strikingly low. I literally worried that I had received a defective, incomplete kit! Nevertheless, I trudged ahead, hoping that my eyes were playing tricks on me in the anxiety of the moment.
In the B4 design, Associated has continued their tradition of "keying" molded parts together. Structurally important components don't bolt up to eachother, they bolt in, with one or more protrusions on the first part fitting into closely matching indentations on the next. The result is a very tough, rigid, monocoque assembly that braces its integral parts against eachother to distribute shock loads throughout the entire frame.
One tradition that has been broken, however, is that of the e-clip, of which there are none on the B4 but those that hold the shock pistons to their shafts. Each suspension pins is fully captured at one end and secured at the other by the head of a 2-56 screw, as seen here:
Granted, these pin capture screws are tiny and easy to lose, but screwing one of them in or out is quite a lot easier than applying or removing two spring-loaded e-clips. Keep a handful of extra screws, and you'll be in good shape.
The manual is clear and concise, using shaded 3D diagrams and easy-to-follow symbols. My kit really was complete; the B4 simply has a very low parts count.
Assembly took about four hours from start to finish, even with forum & email breaks.
The Stealth Factor
The B4 is not an update to the B3, it is a completely new vehicle. It has the lowest center of gravity and the greatest width (the ROAR maximum) of any production buggy to date.
The front and rear a-arms are equal in length for balanced handling characteristics. The inner camber link ball studs are vertical at both ends, allowing fine roll center adjustments.
At the rear, there are two inner link mounting points and three on the hubs. Wheelbase can be fine-tuned via spacers on the outer hingepins, and antisquat can be changed by adding or removing flat, molded shims from underneath the forward arm mount (a separate piece). The rear tower is very, very thick, and is bolted down from the top and into the main chassis and the rear brace, which also bolts to the transmission case. Even the wing mounts have been made into elements of strength, bracing against the shock tower and the top of the transmission. Gone forever are the old, pesky wing mount wires. The kit even includes wing angle wedges for tuning rear downforce! Finally, if you take a careful look underneath the car, the rear chassis plate has an upward concave curve to give the car an important extra bit of rear clearance to avoid bottoming out. In the picture below, yes, the rectangular shape in the center is the bottom of the transmission. That's how serious Associated engineers were about lowering the car's CG.
Up front, the most noticeable feature is the mounting of the shocks, which are now behind the shock tower. This not only protects the shocks from damage if you flip, but lowers the CG slightly. The a-arms are wide and straight, leaving almost no overhang (translation: no more burying the nose underground when you accidentally play lawn-darts with your car). The entire steering column is raked back, "co-planar" with the suspension kick-up. This preserves the Ackermann angle throughout the suspension's range of motion and allows you to set the car to have literally zero bump-steer. Associated will also offer both inline and trailing knuckle arms to help you to adapt the car to vastly different track sizes & conditions.
The mounting of the motor has also been lowered as much as reasonably possible. The full-cage motor guard is molded plastic to absorb the shock of nose-high landings and protect your brush hood. The slipper has also been completely redesigned, with a dual hex-shaped disc system that keys into the spur. Very light, very efficient, no pin! The only downside is that you need to use spurs specifically designed for this new car.
The biggest change in the driveline is the diff. The B4 (and soon the T4) now uses the same oversized diff employed by the GT nitro truck. This will surely lead to greater survivability while affording a higher 2.6:1 (vs. the old 2.4:1) internal ratio better suited to today's high-power, high-RPM motors.
I was actually given the kit you see in the photos above as a loaner, and I wasn't going to get a chance to actually run it. However, thanks to a bizarre turn of events, the situation changed and soon I was running this very car with a stock motor out on Delta R/C's outdoor track. I've owned and run a B3 in the past and seen countless B3's and XXX's running over the past few years. The B4 drove nothing like any of them. The moment I got on the throttle, I noticed that weight transfer was very controlled and there was quite a bit of on-power steering. Coasting steering was phenomenal. I thus expected that this setup (stock) would give quite a bit of oversteer off-power and under breaking. Not so. This is where the limited weight transfer again came into play, keeping the rear end from unloading and losing traction.
Over the rough stuff, the car behaved almost like a truck, maintaining absolute poise and keeping its nose pointed forward and the rear axle squared up well. Over the jumps, the B4 flew completely level with no corrective throttle or brake input, and there was absolutely no drama on the landings. The only thing I would like to change about the stock setup would be the rear shock oil or pistons -- the springs feel right, but there's not quite enough damping, so the rear of car did bounce a bit.
All I can say is, move over Losi. I have traditionally had no special love for buggies, but this car almost gave me a change of heart. The only thing that held me back was the impending release of the T4. If the T4 is to the T3 what the B4 is to the B3, the entire world of electric offroad racing is about to be turned on its lid.
For more information, be sure to visit the official Team Associated site at http://www.rc10.com/. Enjoy these extra photos.