Tamiya #42384 TRF421 Chassis Kit – Pre-Scoop Analysis

First day (30th January 2024) of Nuremberg toy fair starts with some interesting TRF news: TRF421 was released!

Let me write a couple of points in regards to the new release:

(edited 5th February 2024)

Not many common parts from the predecessors TRF420 & TRF420X were carried over. All new chassis + motor layout with same belt length (S3M-348 with 116T) for front & rear. But the most important point is, that the all new A-shaped suspension arms are +7mm longer to the ones from TRF420/420X, which allows for more stable cornering on mid to larger sized tracks. I was struggling here a lot in the past with going with my setups to extreme points in order to achieve corner speed. Also the “classical” suspension block design is gone now with a full pivot ball suspension in place, which will ultimately help to make weight transfer to the spots, where you need it (towards center!). No more major adjustments in suspension track width will be possible. On the other hand (positively) the “active rear suspension” = ARS is now included by default – same as on TA-08 and TB Evo8. Steering seems to be adapted for the new higher linkage position of the knuckles – which will also result in a major rethink of “bump steering” spacers.
There will be 2 different upper decks available offering one more setup opportunities: One seperate topdeck and one “one piece” design. For me it seems, the hex wheel hubs have been reworked substantially. If they are offering a “sleeve” design as known from Axon or other manufacturers … time will tell!
New -5.5mm shorter dampers compared to the ones from TRF420/420X. And for the first time no “classical” damper stays andmore, which in total allows a remarkably lower center of gravity. Also maintenance will be more easy, as the upper mounting point is now turned sidewards. The large mid motor mount has a carbon brace towards back, which is giving additional stiffness to the rear section of the chassis. The 22078 Alu Bearing holders are already included in the kit. Also
Due to the longer suspension arms also the drive shaft axles were reworked and again optimized for weight. The drive shafts itself now are measuring 45mm, which is +1/+2mm to the predecessor. Still the thick design on rear shafts will be used and the 10.8mm pin-shafted design on front, which has been proofed already. However one of the weak points “swing shaft protectors” = blades was obviously not touched. So I expect to have the same part here again #53921.
All new front direct coupling #51744 and rear gear diff #51745 will be in place, which both seem to be a bit more narrow than the ones from TRF420/420X. Functionally they are identical to TRF420/420X.
Maybe Tamiya will also release suspension arms in a hard variant, as the ones on the display model seem to be made from PA-GF, which is the softer material already known from many TRF models before. Also as of now there are no infos regarding an aluminum main chassis. But there is plenty of time for an afterwards release, as I expect TRF421 to be ready for delivery for the start of the (warmer) outdoor season. So no worries, TRF will always work(z)!

Spare Parts?
Most of the unique new parts have been released alongside with the chassis. Here they are:
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

Hop-Up Parts?
Are already released and will (most probaly) also fit TRF421:
22086 Titanium Grub Screw for Camber Adjustment
Not from Tamiya, but also highly helpful:
Axon HLS-SS Super Short Springs (ranging from C2.6 till C2.8)
Square Alu & Titanium Screw Set
For the first time I will also offer a S-Flex Ti Screw option for TRF421 to take the maximum out of it in terms of flex & durability

My personal summary:
TRF421 will be one of the best releases ever done by Tamiya TRF, as it features everything for the upcoming asphalt season and all the upcoming races. With the longer suspension arms there will be also the possibility for more relaxed setups for me to be (finally) more competitive against other car manufacturers.
I am looking forward to post the first unboxing, buildup and first driving session report here on my blog.

As soon, as I will have the order details vom Tamiya you will be able to pre-order the chassis with me. From TRF421 I have also re-tweaked my TRFworkz strategy, which has cost me a lot of time during the last couple of years with modifying parts, trying different tweaks forth and back. With the purchase of TRF421 at sakaguchinetshop.com you will get a full support ticket, which will allow you to have exclusive access to spare & hop up parts as well as being part of my own TRF421 support community. There I will offer a broad range of setups and hints regarding the new top-dog chassis kit from Tamiya TRF.

Pricing, delivery date? I expect TRF421 to be on sale for march 2024. Before the global release date I am offering the TRF421 for pre-order price of 555,00 Euro (+ VAT – if applicable). Shipping will be added as well.

Dai Sakaguchi on 30th January 2024

Leave a Reply

Your email address will not be published. Required fields are marked *

Please reload

Please Wait