I do know why the new Z has such a fast 1/4. My q50 that's now 6MT still has the stock redsport r190 differential with a final drive of 3.133 and holy **** does it take forever to get through the revs vs you guys 4.08 or 3.69 FD on the Zs. My top speed I got to was 164mph and im making 330whp tuned on ecutek (SEB
) vhr motor. That's all due to the super low final drive ratio. The new Z also is a 3.13 final drive and I do believe it's also using a r190 diff except now it comes LSD where our q50 are open diffs. the lower final drives plus boost is really the way to go imo. Check out 60-130 times for fbo vr30 q50/q60 vs boosted vhrs you'll see the lower final drive is much better for boosted applications.