Propeller Performance question
 

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!

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.

If I go the mirage plus route what rpm do your think I might see and which direction would prop slip % go?

I have a 25' Cobalt bow rider that came with a 502 Mag (415 HP) and it was equipped with a Mirage plus 23. Did about 63 MPH at 4200 RPM.

Not sure if this helps or not?

Did you happen to Dyno the motor

in have not had the motor on a dyno. It is a hp500 clone with a 454 mag rotating assembly

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.

Than it is a HP450 clone. :) Yes, Merc made those too. Fun fact.

The single plane intake may not be your best choice under 6000 RPM