From my records, the stock AC pulley is 52mm. At 6200rpm redline and 155mm crank the AC pulley would be seeing 155/52*6200 = 18,480rpm.
If you have a 178 or 181 crank pulley you're up near 21,500 rpm.
Mind you, you're only up at 6,200rpm <5% of the time even if you're an aggressive driver (track).

b22b