The T598 differs from previous direct drive units, including the brand's own T818, in being built around an axial flux motor rather than a radial flux motor. It's a seemingly small but actually quite significant difference.
In radial flux motors, whether inrunner like the T818 or outrunner as with some brands like Cammus, the wheel shaft rotates in a perpendicular orientation with regards to the magnetic field. This can lead to a phenomenon known as "cogging", wherein there is a mild drag on the rotor as it passes through the magnetic flux, either resisting or advancing rotation beyond what's required.
An axial flux motor places the static component of the motor — the stator — between two plates on the rotor, so that the magnetic flux is parallel to the axis of rotation. As a result there's no cogging.
While that's not necessarily Thrustmaster's goal, the T598 is a pretty compact unit and weighs in at 6.4kg for a complete unit including wheel, pedals, and accessories.
In torque terms, the T598 generates a constant 5Nm — comparable to the Fanatec CSL DD/GT DD — but has what Thrustmaster states is a +100% "overshoot capability". This pretty roughly corresponds to double the torque if you're trying to put in enormous amounts of lock very suddenly.
Additionally there's some wheel effects that Thrustmaster terms "HARMONY" and "GEAR JOLT" (yes, in capitals). The former is more or less analogous to Fanatec Fullforce and Logitech Trueforce, adding higher-frequency vibrations, while the latter translates the inertia of gear changes through the rim.
In the standard T598 bundle you'll get the wheelbase itself, a detachable "Sportcar" wheel rim, and a pedal box with two pedals — upgradable to three if you wish.
The wheelbase features a small digital display — "Race Dash" — which can display up to ten pieces of race information, and a quick release clip which allows you to remove the standard wheel rim and fit any compatible Thrustmaster rim.
As for the rim, that's an 11.8-inch (30cm) item featuring magnetic-shift paddles, and a regular array of buttons. A "multifunctional encoder" also allows for up to 12 different functions too.
The pedals are the Raceline Pedals LTE as announced last month, featuring two pedals with Thrustmaster's HEART Hall Effect sensors. They're customizable with different springs and adjustment notches, and a third pedal with load cell technology will also be available soon.
Preorders are available now in some territories for the PlayStation 4/5-licensed T598, with pricing set at $/€499.99. Deliveries are scheduled to begin in November.