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What's a good prop slip #

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Old 10-26-2010 | 10:58 AM
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Default What's a good prop slip #

And how can we change it for the better? Looks like I'm at about 10%
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Old 10-26-2010 | 11:33 AM
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How much power you making?
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Old 10-26-2010 | 12:06 PM
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Originally Posted by Back4More
How much power you making?
I don't know. Somewhere around 6 I think, I have more of a torque 5,000 rpm motor. But I'm changing to a smaller Blower pully on top.. Should get another 50 ish? hp.

The motor in my yellow boat makes about 718 @ 7700.. I was thinking of swaping it w the fountain.. But it's a 468 w less torque and need C12 fuel and to be primed bla bla bla.. Fun thought though

Last edited by mcprodesign; 10-26-2010 at 12:12 PM.
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Old 10-26-2010 | 12:07 PM
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10 5 is awsome for a fountain...they like higher #'s and it is not a bad thing..safes drives and trannys ( if any ) !!!!!
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Old 10-26-2010 | 12:35 PM
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I was wondering what good slip numbers should be. My 32 has 1.5 Bravo's, 28 Q IV's and we got these numbers yesterday. It was in the 70's temp, with a nice wind chop, just what this thing likes, but I couldn't pull the r.p.m like I normally would. Last winter I had a prop guy go over them and it seems I have lost 200 to 300 r.p.m., it would have ran 5200 to 5400 r.p.m. last year.

When we looked at the props last year not all of the blades were the same size

They are now.

2500 - 34
3000 - 46
3500 - 55
4000 - 64
4500 - 72
5000 - 82

Original test sheet shows 27 hydro, 84m.p.h. at 5300 r.p.m.
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Old 10-26-2010 | 04:26 PM
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if you are 10% consider yourself doing great for a single engine boat. If you get much tighter on your slip it has been my experience that you will start breaking drives. However if you stilll want less slip you can go bigger in prop diameter or with more blades.
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Old 10-27-2010 | 04:29 AM
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I agree with 29. Thats why i asked how much power. Some slip is good. Over here on Lake Michigan..."Slip saves drives."

Last edited by Back4More; 10-27-2010 at 08:41 AM.
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Old 10-27-2010 | 08:03 AM
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Is 10% good for a twin or should it be lower?
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Old 10-27-2010 | 08:45 AM
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Originally Posted by Wildman_grafix
Is 10% good for a twin or should it be lower?
My 29 with twins is 6% but it is an older boat with deep drives. My 35 has 12% slip but has high drives and then i put 2shorties on top of that (21 3/8" therotical x deminsion). The 29 is probably a little tight and the 35 may be a little loose but it all comes down to speed and with both boats it is were it is to obtain my goals.
Allen
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Old 10-27-2010 | 03:28 PM
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Originally Posted by 29scarab10
if you are 10% consider yourself doing great for a single engine boat. If you get much tighter on your slip it has been my experience that you will start breaking drives. However if you stilll want less slip you can go bigger in prop diameter or with more blades.
Thanks for your help. I have 2 props. I noticed w my bigger prop it just LOCKS when I get on plane . Not so much w the other prop.. I'll take it easy in my outdrive more w this prop as well..
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