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Xtrac’s P1173 transmission is suitable for use in GT sportscars competing in series such as the GTLM category of the TUDOR United Sports Car Championship.

Originally designed for use in endurance events such as the Dakar Rally, the P1173 has all the qualities required for endurance sportscar racing and can be configured in either a straight through, rear wheel drive transmission or as a 4WD gearbox with a centre differential and drop gear.

Depending upon the application, Xtrac have two differentials, the P247 and P223, which are ideally suited for use with this gearbox.


  • 800Nm (590lbf ft) maximum engine input torque
  • Sequential shift, straight cut non-synchromesh gears engaged – Rev,N,1,2,3,4,5,6
  • Cable lift interlock for the full detent reverse
  • Reverse and 1st gear are integral on the Layshaft
  • Low 1st gear down to 6.25 depending on transfer gear ratio
  • Heavy duty full width reverse gear with the same ratio as 1st
  • Gearbox rear drive output shaft positioned for optimum vehicle and transmission package (+90 → +270 Deg) when used in 4WD configuration
  • L169 aluminium casings
  • Adjustable preload mechanical type plate centre differential with a range of ramps
  • 50:50 fixed front/rear torque split
  • Internal dual scavenge oil system using an eccentric rotor pump and integrated oil control baffle
  • Direct pressurised oil feed to centre differential friction plates
  • Gear change potentiometer, oil pressure and final drive speed sensor mountings
  • Provision for front propeller flange speed sensor mountings when used in 4WD configuration
  • Provision for driving auxiliary drives such as an alternator or a pump
  • Dog ring inspection holes
  • Gearbox weight approximately 62kg

The Gearbox Offers The Following Benefits

  • Light, positive sequential gear change with polynomial barrel tracks.
  • Easily removable cluster for ratio changes
  • Easily accessible oil filter.
  • Numerous output positions available to suit application when used in 4WD configuration
  • Numerous mounting options
  • Cost effective, reliable, lightweight solution

Options Summary

  • 2WD option with the same overall ratio options as 4WD and output in line with input and output drop gears
  • Various propeller flange options
  • Various transfer gear options
  • Speed sensor triggers and sensors
  • Various options for reverse gear interlock
  • Bespoke bell housing casing design to include bell housing mountings, starter motor mountings and other installation specific requirements
  • Epicyclic VCU centre differential with 40/60 torque split
  • Starter motor, Flywheel & starter ring gear
  • Assisted Gearchange System where regulations allow

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