42391 Tamiya TRF421X announced, first photos and official information here..

 It's here..The new Tamiya TRF421X.. let's take a look at the photos... 

Lots of refinements.

So the first thing you can see is that they have indeed lowered the chassis. There are cut-outs in the aluminium deck that shows the motor position has been lowered. 

The driveshafts are now the bearing type.

The differential is revised, but it looks mainly because it has the new driveshafts for the bearing outdrives.

The anti roll bars are different

Also Stiffer arms.. that along with the lower cog are the two things that will impact the cornering speed on the car.. so really happy to see these :)

Revised upper arms with Ackerman steering points.

Shorter shock mounts for inclined shock positions, same ulp shocks with 20mm springs 

30g battery weight, revised motor mount.

Centre stiffener for high grip (inspired by my stiffy bar)

A revised rear body post carbon mount 

New motor mount, look at the cut-outs in the chassis for the 1.04mm lower motor.

Notice the bulkhead alignment pins, a great update for a smooth drive train. 

Again more alignment pins and notice the extra cut outs 

Official Tamiya image and details here

42391 TRF421X Chassis Kit

The TRF series welcomes a new TRF touring car chassis kit. This R/C model assembly kit creates the 2 belt-driven 4WD TRF421X, the latest model in the line of TRF (Tamiya Racing Factory) chassis. Based upon the racing feedback, it employs the updated suspension and low center of gravity setup for superior performance.

Aluminum motor mount

Motor attachment position is 1.04mm lower than that of the TRF421 chassis kit for a lower center of gravity and more stable cornering, and a new design ensures accurate assembly.

2.0mm thick aluminum lower deck

The new lower deck is molded in popular aluminum, and allows lower motor attachment position for optimum balance of chassis flexibility and weight distribution.

Compatible with the TRF421 chassis kit when using new motor mount and 2.0mm thick aluminum lower deck together.

Upper deck

Both types (one-piece and two-piece) of upper deck shape are updated for improved chassis flexibility.

Compatible with the TRF421 chassis kit.

One-piece upper deck attachment

Tubes, dedicated titanium low-head screws and shims are used to attach the one-piece upper deck. Adjust flexibility by using 0–0.3mm shims.

Compatible with the TRF421 chassis kit.

Upper and lower suspension arms (new material) & front and rear damper stays

Damper attachment positions are moved 1.0mm inside with new front and rear damper stays based upon the latest racing test results.

Both upper and lower suspension arms are molded in carbon-reinforced nylon (the TRF421 chassis kit features glass-reinforced nylon) to ensure suspension flexibility and to improve stability on high temperature, high grip, or carpet surfaces.

Compatible with the TRF421 chassis kit when changing both damper stays and suspension arms.

Drive shafts & drive train

New front double cardan drive joint shaft and rear lightweight aluminum universal shafts feature bearings (drive shafts used on the TRF421 chassis kit feature swing shaft caps) to limit friction and speed reduction.

The design and materials of front direct cups and rear differential steel joints are also changed (materials changed from aluminum to steel).

Like the TRF421 chassis kit, direct coupling and oil-filled gear differential are employed at front and rear respectively (currently sold Hop-Up Options and spare parts can be used).

Upper arm mounts

New upper arm mounts feature 1mm narrower pivot attachment width for improved cornering response, and upper arm attachment with bushings to adjust pitching, ensure accurate assembly, and stability under vibration.

Compatible with the TRF421 chassis kit.

Knuckle arm

New knuckle arms—developed based upon the latest racing test results—feature new hole positions for front and rear respectively. The front hole moves Ackermann position outward for more direct steering, and the rear hole moves adjuster rod attachment positions backward for optimum rear grip on low or middle traction surfaces.

Compatible with the TRF421 chassis kit. When using knuckle arms included in the TRF421 chassis kit, four setup options (two choices for front and rear respectively) are available depending upon road surface and driving style.

Stabilizers

Precision stabilizers can be chosen from 1.2mm diameter (×2) and 1.3mm diameter (×1) depending upon road surface and driving style.

Compatible with the TRF421 chassis kit.

Receiver weight & battery weight

Newly added receiver weight (20g) and 0.6mm thick battery weight (30g) ensure optimum weight balance. Receiver weight is attached by one screw and also works as a cooling fan mount.

Both receiver weight and battery weight are compatible with the TRF421 chassis kit.

Available May 26

Thanks to David Joos for the photos

Photos (c) TheRCRacer