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38 flatdeck props

Old 05-02-2013 | 04:25 PM
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From: rogers ark
Default 38 flatdeck props

looking for props to start with ?
over the winter we changed to new motors and drives




38 cig flatdeck , heavy
780 hp blown
konrad drives



last year the boat had worn out 468ci ( another story )
with trs drives
it used a 23p then and ran 60 gps mph loaded
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Old 05-02-2013 | 04:40 PM
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My guess would be try a 28p bravo four blade to start. Depending on where your engines need to be RPM wise makes the difference. But 28's should be a good starting point.
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Old 05-03-2013 | 08:32 AM
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what is the reason to add blades ? 3 blade
4 blade
5 blade
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Old 05-03-2013 | 07:00 PM
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Originally Posted by kennyd
what is the reason to add blades ? 3 blade
4 blade
5 blade
Mainly, to attempt to lower slip numbers.

A old TRS boat with drives deep in the water, may run the best with 3 blades, because there just isn't a need for more blades, as the 3 blade may not slip much. Adding blades normally would just slow the boat down, if top speed is the goal.

Now, a newer boat, with a high x dimension, could be totally useless with 3 blades. Way too much slip, barely get on plane, awful cruise, and even poor top end. So the answer is add blades, reduce slip, boat runs better.

Obviously, this is very vague, and a generalization. Every boat is different. Best bet is to try a general prop, like a bravo 28p. See what RPM that puts you at, and what MPH GPS you see at wot. Those numbers will give a good idea of which direction you need to go.

My buddies old school top gun with 800's runs 30P bravo four blades on his konrads. I wanna say he gets mid 80's around 5500RPM. Your hull is a bit slower, and a bit less power. That's why I think 28's might be a good starting point.
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Old 05-06-2013 | 12:53 PM
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kennyd,

If you can't find props to test, call us and we can set you up in our test program so you can try before you buy.

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Old 05-11-2013 | 07:23 AM
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bravo one props ran the best on my flatdeck with TRS drives. My guess is either 26 or 28 pitch depending on what RPM you want to turn.
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Old 05-12-2013 | 06:55 AM
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Thanks for the input . I have props from bblades to try . With all the info they sent me 30 pitch 4 blades . May get to try them today .
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Old 05-12-2013 | 12:21 PM
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That sounds like a good starting place. Will be interested to see the results

I have 600's and turn 25 hydro motive P5X's at 5100 on my Flatdeck which would be close to a 28 bravo 4 blade

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Old 05-19-2013 | 09:20 PM
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Well how did the test go?
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Old 05-20-2013 | 04:42 PM
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still working on it , ran it saturday for the first time and only ran up to 45mph and backed it down because of the fuel pressure was only at 1lb on 105 gph pumps . so today i ordered new 170 gph pumps to fix that problem .
try again sunday . thanks to bblades i think i have a close prop on it , it came out of the hole on plane easily . so with the new pumps i hope to get to try WOT this weekend .

again thanks to BBLADES !
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