Re: True Hammer Numbers
 

Don Man, don't be to optomistic with these numbers, because true gps , thats not possible. Thats is 0% slip factor, which is mathmaticly impossible, I had a 97 hammer with the 310 hp and a 23'' it ran 61.6 on G.P.S at 400 feet low humidity @ 4600 rpm, thats .08 slip which is good, This boat is still in the family, I sold it to a fellow Texas OSO'er www.boatpropellers.com/propcalc.html

Hey Liquid,

Just curious about what the absolute lowest slip could be with a v hull running an I/O. The reason I ask is that I have used some of those calculators such as Winprop. In order to get my rpm, GPS Speed, and slip to match up I have to lower the slip down to about 7%.

Dave M.

My boat is about 9%

My 23' Concord LS-7 ran 68.5 with a 454 mag (365) and a 23" quicksilver 3 blade @ 5200. When I went to a 2" shortened lower, I saw 72.5mph with a 24" hydromotive (when I could get it on plane). A 24" Bravo1 was just a tick slower, better to plane, but wasn't as stable. Both props also turned 5200rpms. This boat required full trim to run fast and it was very prone to chine walk. You had to pay very, very close attention and be in tune with the hull or you'd lose control. The best hole shot prop with the shortened unit was a 21" mach stern driver 4 blade. The boat was a rocket out of the hole. It also topped out at 60mph at 5600rpm (valve float). Do the slip calcs on that one!

It sounds like your speeds are good numbers.

Props
 

All the props used on my boat were Mirage Plus. The people on the board are correct, these were speedo numbers only and we are at about 900 MSL here in Chicago. The 24P was actually a repitched 25, works perfect for this boat.

Good Luck,

Kirk

I was thinking all summer long how I wanted to try a 24", but could never find anyone who had one to try....
Thanks for the info!

Does anyone know what site Winprop was moved to?