[cole930]

Mark.

There is only 1 ring and pinion, it determines the final drive ratio for all four gears and effects them equally. On a 930 this keeps your gear changes more in the sweet spots where the delay before generating torque in the next gear comes quicker. First gear in a 930 is very short anyway so you don't want a radical change in ring and pinion ratio.

I shifted from 3rd. to 4th. at 145 and have easily seen in excess of 160. I only drive my car on the street and there is no place to use all that top end safely so I choose to change the ring and pinion to make the car quicker in the lower gears and can still run 150 or so in 4th.

I choose to change 2nd and 3rd to dial in those two gears to a little less rpm drop after the shift was made from 1st. to 2nd. and from 2nd. to 3rd. There is a drop from 3rd. to 4th but it is not any worse than it was originaly.

The ring and pinion mod is defiantly not cheap but will make the most significant change in performance of any single mod you can do.

Cole