Strengthen the IRS to transfer more equal torque and reduced lag in transition with a Drag Xa. Add the control of Xa coilovers. Align to these specifications. Max out positive front castor, set all 4 wheels to 0 to .05 toe in, preferably 0, front camber to -.75, set rear cambers to +.5 degrees. Adjust the back end height for drag radial clearances, adjust the front ½? (13mm) lower, set the right rear ride height ½? (13mm) higher than the left rear to compensate for torque on launch. Adjust Xa front dampening to 3 from full soft and the rears to 12 from full soft. Click. Tune. Play! NOTES: The GXP REQUIRES ONLY 3 EP7323s. The EP1167HD differential bushes are high durometer material and will transmit differential noise to the cabin.