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The MT Project

After I got tired of being stomped by the local Wild Dagger aficionados I gave an RS4 MT a try.

Construction

The instructions are extremely clear and the parts bags are well-organized. You can see a scan of the manual for yourself here. When you're putting in the long threaded rod that drives the slipper clutch, make sure you do a good job with the Loctite or it'll appear that the slipper clutch gets loose if you reverse a lot or brake hard. What's really happening is that this rod is backing itself out.

Some Photos

Normal shots

front.jpg (189844 bytes)side.jpg (29756 bytes)rear.jpg (163033 bytes)

Mostly lame image editing games

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Driving

Even on smooth ground, the MT is considerably faster than my Tamiya 2WD cars. When the ground is rough, it immediately becomes apparent that the shocks and all that articulation aren't there just to look cool. They make a huge difference in performance. The car body stays comparatively still while the wheels move all over the place as they try to track the ground. The 4WD makes it possible to both keep up speed and go in a straight line. Driving next to a car without oil-filled shocks (even one with 4WD) it's actually possible to see how much less the MT bounces and how much better it tracks.

The MT will go fast enough to flip itself over if you make a sharp turn on a high traction surface so it's very much worth making the switch to the on-road suspension configuration if you're going to be running on pavement. Also, back off the throttle at the end of a jump under those conditions as well. If you keep it all the way open and the rear wheels touch first they'll actually drive under the car and flip it over. Loosening up that slipper helps too.

It will push a little at full speed, but switching to the short wheelbase configuration helps. On pavement with that setup, and with the shocks in their off-road position, a hard, continuous, turn under full throttle will lift the inside front wheel up easily an inch or so. Softening up the suspension might help, but I haven't tried it yet (besides, the wheel lift looks really cool).

Equipment:

  • ESC: Novak Reactor
    Much smoother than the Duratrax Blast ESC I had in my other cars (no surprise). Tends to overheat and shut down for a few seconds if I run with the inner body on. Also will overheat if I have the slipper clutch too tight and try to climb over a large obstacle (also not a surprise as a stalled electric motor is a dead short).
  • Motor: Trinity Sapphire (17T)
    Only non-stock motor I've ever owned so I've got nothing to compare it to. Seems to be holding up pretty well.
  • Batteries: 3000 mAh NiMH
    Awesome. They definitely like being charged immediately prior to use and lose a noticeable amount of punch if they sit charged overnight.
  • Charger: Novak Millennium
    Very configurable, charges all kinds of different stuff.

Modifications:

  • Ball Bearings
    A must have. I bought the Duratrax since they were considerably cheaper than the HPI kit, but I've often wondered about what the quality of ones made by HPI was like.
  • Ball Diff:
    Gets dirty easily so I don't use it often, but it's well designed.
  • MIP Shiny CVDs
    Nicely made. I tried the HPI universals as well and I definitely prefer the MIPs, since they seem stronger (HPI recently updated their web site saying basically the same thing). They stay pretty clean and run very smooth. CVDs generally beat universals since they're, well, constant velocity (though how much difference this makes off-road is pretty hard to say. Making sure the tires are balanced probably has a much bigger effect).
  • Heat Sink Motor Plate
    Seems to help keep the temp down pretty well. I just added it so I haven't tested very thoroughly.