I've posted before that the 2001 6.2L MPI in our 23' 4,200 lbs. (dry) bowrider hits its rev limiter at 4,800 and 45 mph (gps). The throttle is not completely wide open at those RPMs. The outdrive is a Bravo 3 with 26" Bravo III props. I figure the gear ratio is 2.2:1 b/c with our data plugged into www.go-fast.com/Prop_Slip_Calculator.htm, the slip comes out to a reasonable 17%. If I put a ratio of 2:1 in the calculator the slip works out to an unreasonable 24%.
Anyway, at $1,500 CDN a pair, I'm not going to be buying several sets of props to try to find the proper pitch for this thing.
My question is whether, given a gear ratio of 2.2:1, would going from a 26" to a 30" pair likely be too large a jump? Normally, with a boat with, say, an Alpha leg and a lower gear ratio, you wouldn't want to jump more than 2"; is the consideration different when your gear ratio is relatively high?
Anyway, at $1,500 CDN a pair, I'm not going to be buying several sets of props to try to find the proper pitch for this thing.
My question is whether, given a gear ratio of 2.2:1, would going from a 26" to a 30" pair likely be too large a jump? Normally, with a boat with, say, an Alpha leg and a lower gear ratio, you wouldn't want to jump more than 2"; is the consideration different when your gear ratio is relatively high?
