223 Prop Test Results
 

After the longest winter in my life, splashdown date was tuesday for some prop testing. As some of you know, I bought a 223 last December and got to go out twice before winterization. The boat saw a top speed of 68.7@5200 with a Hydromotive 4-blade and about 50 gallons of gas. The motor is a Merc 454/425 with a little bigger Ultradyne cam and Gil exhaust. I'm thinking about 460 to 470 HP. The Mercury website suggested a Mirage Plus 25P so I got one to try. Here is the results. Any help would be welcomed :D :D

All speeds are GPS- about 3.5 less than the speedo reads

25 Mirage Plus

3000 RPM = 40.7
3500 =49.8
4000 =58.6
4400 WOT =64.2

23 P Hydromotive 4 blade

3000 RPM =35.1
3500 =43.7
4000 =52.4
4500 =61.3
5000 WOT =64.7

:(


Tests were done with a full tank of gas for both props (79 Gallons) and just myself onboard (200 lbs.)

Did the heat (97) rob me of 4 MPH?

Craig,
I'm suprised the 25P didn't work better for you. Now I have to rethink my choice of props. With the stock 330 HP my 223 was running 61 on GPS with a 23P Mirage Plus. I get my new motor back tomorrow now and talking to the builder, the motor was built to make it's peak around 5400 RPM +. Considering I will be around 470 - 500 HP, I may have to look into having my 23 labbed into a 24, if your only getting 4400 out of the 25. I could see temperature having something to do with your 200 lost RPM's, but I would figure that the water temp, even in Virginia is still pretty cool this time of year (assuming the boat is raw water cooled).

T T T