1" or 1 1/8" prop shaft?

[flatties forever]

At what point (HP wise) do I need to have a 1 1/8" prop shaft vs a 1" prop shaft. Looking for the next boat and I don't want a weak link in the drive train. Don't want the, "any moron knows you can't but that much power infront of that POS part). I always seem to be the moron that "never knew that--damm".. Want to stay ahead of the snow ball-- if possible. Thinking Shiada RC but not positive yet.

[HighVoltage 329]

It's not only power but how it hits and also weight. I've twisted 1 1/8" prop shafts in 19' Halletts with a hard hit of NOS. The smaller the shaft the less drag, that why many SS boats run 7/8" shafts. In a 21' I would want 1 1/8" especially if your going to be shifting gears.

[obnoxious001]

I wouldn't pass up the right boat if it had a 1" shaft. I raced my 20' Schiada for many years with a 505 cu in Gentry turbo'ed engine, turbo 400 trans and a 1" shaft, with no failure. I was shifting it pretty hard pulling a couple of the better skiers out of the water too.

[HighVoltage 329]

Most 21' race boats I've seen have 1 1/8". I think it's preferred but not a must.

[obnoxious001]

Most 21'ers I've race boats seen have 1 1/8". I think it's preferred but not a must.
I agree, if I had the choice without changing everything over. The ski race rules even stated 1 1/8" except on older, existing boats, if I recall, or something to that effect. I was just pointing out that I ran something close to 1000 HP thru mine, and did not baby it without failure.

[schiada96]

I agree, if I had the choice without changing everything over. The ski race rules even stated 1 1/8" except on older, existing boats, if I recall, or something to that effect. I was just pointing out that I ran something close to 1000 HP thru mine, and did not baby it without failure.
me too just k500

[flatties forever]

Thanks for the help. I won't be pushing more than 650 HP, so I won't worry about it too much.

[Budweiser]

Perhaps you'll be changing your name to "Flatties until I decide to get a Shiada"?
See you in the spring.
-Seth-

[palhal]

There is a 7 MPH differance between the two sizes.----PALHAL

[flatties forever]

7 MPH difference??? You talking when in excess of 100mph or something??? I'm only looking to run mid/high 70's. Can't believe there'd be that much speed loss at those comparatively mild speeds.
And Bud Man-- FF is a state of mind. Not necessarily the boat i'm drivin. If the price of gas keeps risin', I might be riding around in a 12' Gamefisher with a 10 horse Merc, but I'll still be Flatties Forever.... Sad but true.