by Joel Navarro
The time has come to build Tamiya’s newest mid-line sedan offering, the TA07 Pro. Ever since I first laid eyes on this car when we featured it on rccaraction.com, I fell in love with its unique design and overall look. Other than its unique chassis, other notable features of the TA07 Pro are its one-belt design drivetrain and multiple motor positions. Enough talk, lets get to the build!
The TA07 Pro comes packaged in a handsome box that includes a top handle that will make it easy to transport the car or your arsenal of tuning parts and tires.
When you first open the box, the first thing noticeably missing is a body. Tamiya leaves that choice up to you as well as tire choice. Spoke wheels are included.
The TA07’s chassis is unlike anything you’ve seen before. Gone is the tub design in favor of bottom plate and side rails.
The view from the bottom can almost be mistaken for a carbon fiber chassis. The nylon plastic plate features countersunk screw holes and a symmetrical shape that should offer the same flex on both sides of the car.
There is a lot of flex in the chassis when nothing is mounted on it. I’m sure the chassis will be a lot more stuff when the car is finished, but this is a good indicator of the flex that is available.
The TA07’s instruction is well laid out and easy to follow, even for the first time builder.
The parts bags are clearly labeled and include the screws you will need for the step you are on. If you’ve ever built a car where you have to search in other bags for the screws you need, you know it can be annoying and add time to the build.
Suspension
The very first thing on the build is prepping the rear arms to be mounted. This includes installing the inner hinge pins with pivot balls, droop screws and blue aluminum ball studs for the shocks.
Plastic hinge pin holders secure the rear suspension arms to the chassis. The manual does mention that Tamiya 418 sedan parts will fit the TA07, so you can swap in aluminum hinge pin holders later if you’d like.
Next to install is the bottom half of the rear transmission case. Noticeably absent are belt tension cams that mount to the rear differential. The belt tension will later be adjusted via pulleys on the motor plate.
The front suspension arms were next and received the same treatment as the rear arms minus the plastic pivot balls on the hinge pins.
The front arms are fastened to the chassis with similar plastic hinge pin holders as the rear suspension.
The bottom half of the front transmission case bolted on next. Note that the TA07 Pro is sway-bar ready. Sway bars are not included, but the TRF418 sway-bars will fit.
Drivetrain
Moving towards center of the car and the drivetrain, the manual has you assemble the first pulley of the drivetrain that attaches to the spur gear via a blue aluminum mount.
The spur gear assembly then mounts to the center of the blue aluminum motor plate with one screw. The belt tension is controlled with a large toothless plastic pulley and a pair of bearings that mount and slide on slotted holes incorporated into the motor plate.
Here’s a backside of the motor plate. The motor mount holes look like they will accommodate a large range of gear ratios.
The top U-shaped sections of the motor plate will accommodate the two screws that will hold on the spur gear cover.
The gear differential assemblies are pretty standard and assemble quite easily. The white plastic spider gears are snug at first but will break in after you the car is ran a couple of packs.
Here are both differentials fully assembled and filled with the supplied shock oil. The front and rear diffs are identical.
The next step was to mount the motor plate assembly, top halves of the front and rear gear boxes and fitting the drive belt onto all the pulleys like the serpentine belt on your real car.
Steering
The steering assembly was next to go together. To keep the price of the TA07 down, the bellcrank pieces are made of plastic. They can be upgraded with aluminum pieces from the TRF418 if you choose.
The steering assembly mounts nicely on the blue aluminum steering post that are then covered with plastic spacers that will be held in place with the chassis’ top braces.
Universal Drive Shafts and Chassis Braces
Universal joints are used on all four corners of the car. Make sure you apply a generous amount of black grease when you assemble them for smooth operation.
The universals install into the steering knuckles through the C-hub. The axles ride on ball bearings.
The C-hubs are secured to the front suspension arms via an outer hinge pin held in place with a setscrew. Note the top chassis braces installed.
The front blue aluminum camber links are assembled and installed with a 15mm gap between the plastic ball cups.
The rear chassis braces are now installed to add stiffness to the back end of the chassis.
The rear camber links are installed just like the front, but with a 14.5mm gap between the plastic ball cups.
The front and rear shock towers are secured to the top halves of the tranny cases via four countersunk screws.
I’m a big fan of the satin silver finish on all the screws that gives them a titanium screw look even though they are steel.
Shock Towers
Shocks
Ok, the time had come to assemble the shocks. I was relieved to see they use a bladder for oil compensation, the easiest type of shocks to bleed. The shocks use an aluminum body with a 10mm bore and 3mm shock shafts.
Here are the shocks fully assembled. They are the same front and rear using medium white/yellow springs and 40wt shock oil.
The shocks snap into place nicely and provide smooth damping action.
Electronics Installation
After the shocks, the manual begins to mount the electronics. To hold the motor screws and included 20-tooth pinion temporarily, I installed a Mabuchi motor until I receive the Tekin Gen3 17.5 I will use for testing.
The spur gear cover secures to the motor plate with two screws. Hidden underneath and installed on the gear cover is a bearing to guide the drive belt forward and prevent it from hitting the end of the gear cover.
The floating servo mount is mounted to the centerline of the chassis and suspends the servo off the chassis to allow symmetrical chassis flex. Here is the mount show with the optional antenna mount if you choose to run the car without the center chassis brace.
Here is the floating servo mount with the optional antenna mount.
The center chassis brace adds a lot of stiffness to the chassis when installed and it incorporates an antenna mount.
The motor cover provides protection against impact and scoops air to keep the motor running cool.
I’m a fan of the battery quick release battery clip. Yes you can tape the battery in and save a bit of weight, but who wants to deal with tape.
I test fitted a battery I had laying around and it fit in the TA07 perfectly.
The lightweight stiff bumper doesn’t have any holes incorporated into it to shave weight and can actually protect the car in a hard impact.
The Build is Complete!
The TA07 Pro is complete! It is ready for electronics, tires and body. I chose the Tamiya Subaru BRZ that is being painted by Charlie V of C-Built Designs.