Tamiya Mini 4WD Building & Option Part Basics

Tamiya Mini 4WD kits are a fun way to get into racing cars. They are easy to build, very inexpensive, teach basic mechanics of a working mechanical system, and teach basic physics principles. This blog post takes a look into building an efficient box-stock kit and then adding basic option parts to make a basic Mini 4WD kit go faster around the race track!

It’s all in the build: A well-built car is a fast and efficient car.
We’re starting with the Raikiri Japan Cup 2016 MA chassis, kit #95093. I love the looks of the car. It’s mean and sleek looking. The MA chassis is a very easy kit to build through its use of a one-piece chassis. Simply follow the directions in the order in which they were written and make sure not to hurry or skip building steps. When cutting the parts off the parts-tree, make sure all the “burrs” are removed. You can do this by using good Tamiya side cutters when you initially cut the parts from the trees. If you still have burrs, simply use a file or sand paper to smooth out the remaining edge of the burr. The deburring is especially important with the tires and rollers. The smoother the contact area is the faster the car will be around the race track. As for the grease used in the moving parts, I recommend the JR Mini 4WD F (Fluoropolymer) Grease, item #15383, but the included kit grease will suffice, it’s just hard to get out of the tube. Remember race fans, a little grease goes a long way. Add just a small amount to where the instructions tell you to; it will work in as the car runs and breaks in. Also, keep this in mind, the tires should spin easily when turned by hand if everything is built correctly and if everything lines up straight. By removing the excess “burrs” on the parts and by applying the recommended grease, you will end up with a fast box-stock Mini 4WD race car. stock kit

stock kit 2

Take it to the next step: Adding Grade-Up Parts
So, you have a good box stock race kit. Now what? Everyone wants to go faster, right? Now that we’ve got a fast box-stock car, let us take it to the next level. The following two Grade-Up Option parts will take your car into “Super Stock” status. For this we’ll install wheel axle ball-bearings, item #15287 and ball-bearing rollers, item #15426. These simple options alone will greatly improve the performance of the car. The ball bearing rollers are mounted in the same hole locations as the box-stock plastic roller locations.

Now let’s go faster and look cool: Adding decoration items and raw horsepower.
Time for the modified motor! Motor selection depends on track lay-out. For a speed track, go with the Mach-Dash motor, item #15433. I also suggest using the new HG Carbon Wide Front, item #15498 and Rear, item #15499 roller stay plates. These are good options because they help reinforce the chassis, and also because they’re cool looking. For this modification you’ll need longer screws, spacers, and lock-nuts, such as the ones found in item #95233 Screw Set. Since we’re using these wide plates, we’re going with the maximum allowed width under Tamiya Mini 4WD racing rules, which is 105mm. The rear rollers are mounted in the holes marked 19 (for 19mm) with a 3mm spacer on the bottom and 6mm and 1.5mm on the top. This set up increases the stance of the rear rollers which improves stability for greater speeds. As for the rear of the car, the rollers are mounted in the 19-location hole and a single washer is used between the Bearing Roller Spacer and the roller plate. There you have it; is it a winner? Maybe? But it will be fast! carbon plates

Did someone say jumps?!: How to tune your car for jumps.
For technical tracks with ramps and jumps, we’ll go with the same speed set-up as mentioned above with the wide roller stance set up settings, but now we’ll install the Slimline Mass Dampers, item #15501.This option part absorbs the impact from landing off jumps to help reduce bouncing. The less your car bounces, the more speed it will maintain throughout the race. You’ll also have to motor down when racing on technical race tracks. For this I recommend the Atomic Tuned 2 Motor, item #15489. This motor is perfect for tracks that are more technical with turns rather than long straights. You may also want to install the Brake Set, item #15441, because this will help slow your car down at the base of a ramp, thereby reducing the chance of your car jumping too far and flying off the race track.
mass dampers 1 Mass dampers 2

That concludes building a basic box-stock and fast Mini 4WD race kit and getting to know some of the basic tune-up parts to make your car faster as you progress with your Mini 4WD racing hobby.