I know all bows are different but we just performed a test on a diamond hornet at the shop to answer the question you were asking. The bow was set at 30" draw 75 lbs shooting a 348 grain arrow at 316 fps with string loop only. After adding cat wiskers the speed was 314 and after adding the peep(tru peep) the speed was 312. We tie the cat whiskers on with fast flight material approx 3" from the cam and idler wheel and trim them so that the whiskers are about 1½" long.