[Source] Turbothrust converter coils were components in landspeeders and starships that limited the amount of z buildup so the machine would not break down. They were in XP-38 sport landspeeders, X-wings and Alliance to Restore the Republic T-47 airspeeders. The land speeder carried a coil between V5 to V9 gauge while starfighters, needing to withstand more z buildup, carried V12 to V18 gauge.