42384 Tamiya TRF421 Exclusive first photos and details

Its here the Tamiya TRF421 Take a look at these exclusive first photos with details below :)

Instantly, you can see that this new chassis has taken a big leap in design from the previous generations of TRF cars. It has many of the design elements of other top-end competition chassis. Look closer though and you will see Tamiya has engineered their own philosophy in many of these components.

As you can see the car comes with two upper deck designs. A single solid asymmetrical deck and a split upper deck. This provides a wide range of flex options. Both are included in the kit. 

The motor has moved 22.7mm towards the centre of the chassis. This means Tamiya have returned to their mid pulley design which has been copied by many of their competitors. The 20t centre pulley is connected to the diffs with dual 116t belts.  This layout has become the standard in all other race chassis so it is reassuring to see Tamiya return to this layout with for the TRF421.

The carbon bumper plate is longer as it now also acts as a brace for the front chassis. The foam bumper is now the TA08 design. You can easily add weights in the front of this car, and also something else ;)

The front and rear knuckles are inter-changeable. They still look to have the same bearings (10x5). Once coupled up with the aluminium upper arms they are the same front and rear. Allowing ARS without any option parts. 

The driveshafts are the same design but are longer (45mm) to accommodate the longer suspension arms. The rear axle is new and is lightweight and even more durable.

Here you can see a good close up of the aluminium shock towers. They are firmly attached to the bulkheads. You simply add or remove shims to change the shock angle. This is a reliable method and allows fine tuning down to 0.1mm.  You will notice that they are more inline that some other makes. This is good as it reduces the chassis overhang.  

You can also see the new super low SSBB V2's that are 5.5mm shorter. They use the lo mount retainers and it is great to see that they use 20mm springs so us racers can use the ones we already own. The shocks also have a new oil seals to ensure they have the same piston level as before. 

Here you can see the upper bulkhead. Notice how it has a two part design. This allows different casters to be easily set . (Notice the alignment lines).

You can set the caster to 3, 4 or 5 degrees 

You could also add spacers to lengthen the upper arms and change camber gain if needed. You can also see the 5g weights under the steering arms.  The steering arms look the same, however the steering bridge is different, as the turnbuckles need to be higher to avoid the new roll bars.

The adjustable caster is also available in the rear of the car. Here you can set the caster to -0.5, -1.5 or -2.5 deg. 

Here is a low down look at the rear. The roll bars are low, but not too low to the ground.  In the kit you will get two 1.1mm roll bars, one 1.0 roll bar and one 1.2mm roll bar.

The aluminium diff retainers (0.8mm) are also included in the kit.

Here you can see some of the upper flex attachment points in the motor mount. Also you can see the plastic battery mounts with will be lighter and more versatile than the aluminium ones we have on the TRF420X

Here you can see the rear bulkhead. It has the new Tamiya suspension arms. These plastic arms are 7mm longer than the TRF420 arms. They also are also attached via 5mm pivot balls, not a shaft. This in turn means that the suspension mounts that we have used for nearly two decades are a thing of the past. 

 The rear differential and front spools are also entirely new. They are both still 37t, but more narrow to compensate for the narrower bulkheads. The internals are the same so many of the existing parts will still be able to be used.

Here you can see the underside of the chassis. The new car even has Shorty battery layout for Mod racers. You also can also see the inner pivot points for the 7mm longer lower arms.

The new car has A arms that are plastic for both upper and lower arms. Many manufacturers use carbon lower arms and turnbuckles for the upper arms. It is good to see Tamiya making composite plastic arms. These will be lighter as they will not need as many attachments mounted onto them to work. 

The suspension arms also have three settings for the lower attachment points. This is done by swapping out the aluminium pills that are placed in them. 

The motor mount also looks to have a recess for the esc wire.

Here is a another close up of the new motor mount. You can also spot the rear stiffener bar that allows more chassis flex modifications.

The new spur gear mount allows easy removal and ensures the battery can be close inline to the centre of the chassis.

The mount goes along the centre line. With some flex adjustments

Here you can see the new lower mounted roll bars. Along with the rear facing bodyposts that are mounted on a 3mm carbon plate. This carbon plate also is a brace for the rear bulkhead to ensure it  stays aligned. 

The New Top Dog

We have a long tradition of high-spec touring car race chassis here at Tamiya, and the Tamiya Racing Factory now brings you their latest masterpiece: the TRF421 Chassis. This 2-belt driven 4WD carbon fibre double-deck design is loaded with new features such as an updated drivetrain, a new lower deck shape, front and rear upper A arms and new shorter dampers, all of which promise to translate into serious speed on the track! Other notable features include a choice between one- and two-piece upper deck layouts for different chassis flex, plus updated suspension geometry that keeps the chassis more stable. Take this opportunity to get a hold of our latest top-end chassis, and enjoy some seriously fun racing!

  • The drivetrain uses a front direct coupling and rear oil-filled gear diff. Equal length front and rear drive belts minimize pitch.
  • Suspension arms are a rigid “A” design with 7mm longer span for stable roll, while upper arm mounts can be slid to adjust caster. Three damper pivot positions are provided.
  • Dampers are 5.5mm shorter than on the TRF420X, for a lighter chassis and lower centre of gravity. Attach them directly to aluminium mounts and fine-tune with spacers.

Body motor, tires R/C equipment, battery pack and charger are sold separately.

Here you can see some of the new components. The new spool, suspension arms, drive shafts

Here are the parts that have been announced so far.
42385 45mm LW R Swing Shafts
42386 TRF421 Wheel Axles
42387 45mm Drive Shafts for DC
42388 Axle Shafts for TRF421 DC *2
51738 TRF421 Damper Oil Seals
51739 TRF421 A Parts Upper Arms
51740 TRF421 BB Parts R Body Posts
51741 TRF421 C Parts Uprights
51742 TRF421 D Parts Sus Arms
51743 TRF421 Damper Parts
51744 TRF421 F Direct Pulley (37T)
51745 TRF421 Gear Diff Set
51746 TRF421 Drive Belt

My Summary

As you can see from the photographs. The new TRF421 really is a big change from the previous generation of TRF's. I am really excited to see this jump in design and it looks very contemporary.

There are similarities with other chassis out there, noticeably the MTC2-R. Although there are a lot of differences when you start to look at the details. The lower arms are not carbon, this will have different flex characteristics and will also be nice and durable. Also when you look at the motor mount design there are a lot of different flex points. The bulkhead design is also potentially better than most with an easy caster adjustment, and more inline shock towers. 

I wont know if this all works well until I get mine on track, but the performance of the TRF team in Japan has been great as they have tried out various different elements of this design on their TRF420X test mules.

Overall this looks like a very exciting new update for us TRF racers. It's the biggest leap in TRF design for well over a decade and I cannot wait to get this out on the track when it arrives in spring. 
TRF421 6129637463690959876

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