Propeller Performance question
#1
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Joined: May 2025
Posts: 20
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From: Kansas
Hello,
I have a 24' IMP Europa Bow Rider with a 454 making in the 400-450hp range slightly modified with heads, cam, and intake. Was able to run 4300 WOT RPM at 53MPH this weekend with a 24P Bravo 1 prop. Boat had a good hole shot but I feel like the WOT RPMs should be closer to 5000rpm to take advantage of my full roller vavletrain and single plane intake. Thinking of going to a 22p bravo 1 or a 23p mirage. Any suggestions would be appreciated!
I have a 24' IMP Europa Bow Rider with a 454 making in the 400-450hp range slightly modified with heads, cam, and intake. Was able to run 4300 WOT RPM at 53MPH this weekend with a 24P Bravo 1 prop. Boat had a good hole shot but I feel like the WOT RPMs should be closer to 5000rpm to take advantage of my full roller vavletrain and single plane intake. Thinking of going to a 22p bravo 1 or a 23p mirage. Any suggestions would be appreciated!
#2
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Joined: Nov 2005
Posts: 1,223
Likes: 768
From: Wichita, Kansas
Yeah...something is way off...you're at nearly 19% prop slip! And we know Rev 4 props bite HARD and hold good so...something is amiss. Personally I would try a 23" pitch Mirage Plus.
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#3
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Joined: May 2025
Posts: 20
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From: Kansas
If I go the mirage plus route what rpm do your think I might see and which direction would prop slip % go?
#7
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Joined: Aug 2019
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From: BC
4300 @ WOT, you're pretty much lugging the engine.
I calc 19% slip with your 24p Bravo 1 prop, 1.5 gear ratio @ 53mph. 4300rpm.
10-15% slip is optimal. Less slip is like running slicks for tires. It shocks the drivetrain.
What Cam is in the engine? That really directs where the peak HP curve lays over. Higher WOT rpm is easier on the engine and the drive.
I would be looking for a 21p prop, and 13% slip.
That's 60mph @ 5200 rpm.
450 hp should put a 24ft hull to 60mphs If faster, then 5400-5500 is gtg.
Props can be off a bit on their pitch. Cupped props dynamically add pitch.
I calc 19% slip with your 24p Bravo 1 prop, 1.5 gear ratio @ 53mph. 4300rpm.
10-15% slip is optimal. Less slip is like running slicks for tires. It shocks the drivetrain.
What Cam is in the engine? That really directs where the peak HP curve lays over. Higher WOT rpm is easier on the engine and the drive.
I would be looking for a 21p prop, and 13% slip.
That's 60mph @ 5200 rpm.
450 hp should put a 24ft hull to 60mphs If faster, then 5400-5500 is gtg.
Props can be off a bit on their pitch. Cupped props dynamically add pitch.



Yes, Merc made those too. Fun fact.
