OFNA Ultra GTP RTR

Radio Control Car Action, Jun 2001 by Gonzalez, George M

PERFORMANCE

The Force .21 engine refused to start on the first attempt, and I was baffled for a time. I checked the glow plug, which was "glowing" as it should, so I reinstalled it, made sure that the high-end needle and low-end air/fuel mixture were set to their default factory settings and tried again. This time, the engine fired after only a few tugs, but it stalled almost immediately. I adjusted the idle speed screw for a faster idle and gave the engine cord a couple more tugs. Bingo; the engine fired and settled into a steady, but slightly high, idle. I let it idle through the first two tanks of fuel with the car sitting on top of an off-duty starter box. I had to adjust the idle-speed screw a couple of times because the engine started to slowly rev up as the piston and sleeve began to wear in. I followed the engine break-in instructions to the letter for four more tanks of fuel, and before I knew it, I had the Ultra GTP blazing around the empty mall parking lot I chose for the test.

If you're looking for a fast car, the Ultra GTP won't disappoint you. It accelerates violently and tops out at 41.7mph. Even so, it felt undergeared, and I'm confident it could handle a taller ratio. With OFNA's optional speed, I bet 60mph would be possible. I was very impressed by how the Ultra GTP handled all the power. It tracked perfectly straight both under power and during hard braking.

Incidentally, the disc-brake system can bring the Ultra GTP from full speed to a dead halt in less than 10 feet, which is impressive for a heavy car with a single disc brake. At high speeds, the Ultra GTP pushed slightly, but it stayed planted when exiting comers under hard acceleration. This makes it incredibly easy to drive. It did exhibit considerable body roll, which was mostly noticeable when going through a slalom course. I decided to try to limit this roll by stiffening the swaybars. I did this easily by sliding the front swaybar's control links forward and the rear swaybar's control links rearward. These little tweaks made a big difference: the car displayed less body roll and was able to hold a tighter line through my slalom course.

I drove the Ultra GTP until the sun went down. It performed faithfully even when I was a little sloppy and allowed it to clip a cement parking-space stop at full speed. The impact was so hard that the rear wing was completely tom off and the rear right wheel was cracked. I was very reluctant to inspect the rest of the car because I expected to find a ton of damage. To my surprise, the chassis didn't have a scratch. This thing is a tank!

THE VERDICT

The Ultra GTP is fun, fast and extremely durable-all excellent traits for an RTR vehicle. The shaft-drive 4WD system and supple suspension provide tremendous traction on any on-road surface, and the way the car rolls and sways as it comers enhances the driving experience. Add to that the sounds, smells and gut-wrenching power of the big-block engine and you have the makings of an attractive RC package that should appeal to enthusiasts of all levels.