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flatties forever
11-16-2007, 10:45 PM
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
11-17-2007, 08:43 AM
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
11-17-2007, 09:24 AM
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
11-17-2007, 10:47 AM
Most 21' race boats I've seen have 1 1/8". I think it's preferred but not a must.

obnoxious001
11-17-2007, 11:00 AM
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
11-17-2007, 11:47 AM
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
11-17-2007, 03:04 PM
Thanks for the help. I won't be pushing more than 650 HP, so I won't worry about it too much.

Budweiser
11-19-2007, 08:25 PM
Perhaps you'll be changing your name to "Flatties until I decide to get a Shiada"? :D
See you in the spring.
-Seth-

palhal
11-19-2007, 08:36 PM
There is a 7 MPH differance between the two sizes.----PALHAL

flatties forever
11-20-2007, 02:55 PM
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.

g935
11-20-2007, 07:47 PM
"There is a 7 MPH differance between the two sizes.----PALHAL"
I was told to switch to a 1 1/8" propshaft. After doing so, I was informed that I would loose 7 mph. also. :mad:
Geoff

Fiat48
11-20-2007, 07:51 PM
Just buy a quality 1 inch prop shaft. Call V drive Tom and order one.
In general...Blown alcohol and up use a 1 1/8 prop shaft. You don't need 1 1/8.

palhal
11-20-2007, 09:15 PM
Just buy a quality 1 inch prop shaft. Call V drive Tom and order one.
In general...Blown alcohol and up use a 1 1/8 prop shaft. You don't need 1 1/8.
I'll second that.---PALHAL

flatties forever
11-21-2007, 08:35 AM
Appreciate the follow up. Will fill comfy with a good 1" prop shaft.