At the time of the release of the Yeah Racing drive train And Steering Upgrade Kit For Tamiya M05 M06, Tamiya’s own version of their update kit was released at the same time too. We thought it would be beneficial to our customers if we did a side by side review.


First we will do a comparison of what’s included in both kits, we start with what Yeah Racing offers in their upgrade kit:


After opening the neatly packaged Yeah Racing kit, we can see they packaged everything individually in small plastic bags to make it easier for you to spot where everything is. After taking everything out, we can see that they included:
  • Ball Raced Aluminum Steering Rack
  • Aluminum Steering Shaft
  • Lightweight Aluminum Rear axle stubs
  • Aluminum Front Spool Axle
  • Graphite body post stiffener (rear)
  • Aluminum front universals
  • 6mm Hex Adaptors
  • Serrated Lock Nuts (4pcs)


We now take a look at what’s included in the Tamiya upgrade package:
  • Ver II. motor mount with cooling bars
  • Servo Horn to replace the plastic part offered in the M05 kit
  • Ball raced steering rack
  • Aluminum steering shaft.
  • Servo Mount

It is evident that there’s more included in the Yeah Racing upgrade package, upgrades both steering and most of the drivetrain. For example, the included aluminum rear axle and front universals will allow for a lighter drive train which will result in better acceleration. The included spool allows for users to fine tune their power delivery from the motor to the wheels. A nice touch were the aluminum hexes, the kit included plastic hexes were a pain to deal with. They would fall off whenever we changed the wheels, and eventually would wear out due to them being plastic. Whereas Tamiya focuses more around the front end of the car, including a motor mount which will allow for better cooling due to the cooling bars. The servo aluminum upgrades we feel should have been standard, the kit plastic servo horn would wear out and the car would struggle to find center after coming out of a corner.
Next we will take a look at the steering rack and compare it side by side :
The first difference we saw was that the center line was marked on the Yeah Racing upgrade part, we found it to be very useful when we were calibrating the steering links to be center.  Different to the Tamiya offering as well, the Yeah Racing steering rack includes one extra ackermann setting hole, although not essentially required we feel it’s better to allow for more tuning options.
Now for an aerial view of both the steering racks in action, it is evident that both can achieve max steering lock.
The included spool fit perfectly in the Tamiya gear, no modding or fumbling with shims to get the correct width needed.
We really liked that the Spool outdrive and universal combo uses swing shaft protectors as this reduces wear on the aluminum parts and you only replace the plastic swing shaft protectors when they wear out.
Included in the Yeah Racing kit, was this rear body post stiffener. We feel this is a must for every mini racer, as this prevents the rear of the body from swaying about. Which is common with mini bodies, as they tend to be very tall.
Scoring and Conclusion:
Tamiya 84407
Functionality: ★★✰✰✰
Form: ★★★★★
Packaging: ★✰✰✰✰
Value: ★★★✰✰
Yeah Racing TAMC-S02
Functionality: ★★★★★
Form: ★★★✰✰
Packaging: ★★★★✰
Value: ★★★★✰
Even though the Yeah Racing conversion Kit features a higher price tag, we feel is better value. The extra parts included far outweigh the price difference and we feel those extra parts are essential to completing the  car. Tamiya opted for a anodized black look whereas Yeah Racing went for the iconic Tamiya Blue to give racers that unique Tamiya look. The box packaging of the Yeah Racing conversion kit was very useful to us whilst building it up, it gave us a place to store all those loose parts whilst building and a nice place to store the old parts.