MRC drift steering for BT-01 MR or FR

Installation notes

• Choose one full set: MR for midship rear-drive, FR for front-motor rear-drive. They are alternative routes. BT-01 factory FF/MR/FR rearrangement is a separate base-chassis capability, not a new MRC drivetrain mode.
• Both packs supply front arms/knuckles, free axles, eight bearings, steering wipers/mounts and the associated rods, spacers and fasteners. Retain stock chassis, rear transmission, wheel hubs/pins, usable shocks, screws and the B9 steering-rod adjusters as the relevant instructions specify.
• The MR sheet is BT-01MR Ver. 1.11. It relocates the front body-post base, trims the bumper and recommends a 2.7 mm drilled attachment for extra body-mount security; drilling the optional wiper extension attachment is also recommended, not required for driving.
• The FR sheet is BT-01FR Ver. 1.11 and depends on the Tamiya FR supplement, especially step 7 gearbox assembly. It trims C4 for linkage clearance, reverses the differential orientation relative to MR and uses supplied rubber rings to retain the C1 joints.
• FR raises the servo mount on supplied 10 mm standoffs, relocates battery/body mounting and trims body-post/servo-horn interference. It adds the supplied 8 mm preload rings with stock shocks to recover ride height under the front motor load.
• The current full instructions use a front hub-plus-offset baseline of 14 mm, normally stock 6 mm hubs plus 8 mm-offset wheels. Check actual body clearance. MR recommends a high motor position and about 7 mm ride height; a lever-ratio plate is a conditional roll-control choice.
• Use a separate drift gyro, a compatible servo/radio/ESC/motor system, and drift wheels/tires suited to the surface. These electronics and tires are not supplied by the conversion pack. Match any replacement servo horn to the servo spline.
• Adjust gyro gain to avoid steering oscillation, set servo end points after assembly, and check tires, body and linkage through the full suspension and steering range. Maker setup dimensions are starting points for its P-tile surface, not guaranteed settings for every surface.

Sources