bblades help me.
 

I have a 98 donzi 22zx 454 efi (throttle body injected) 310 hp. I am turning 24p bravo 1 stock prop 4300-4400 at wot 62 mph. What do you think is my best option i am looking to get the rpms in the wot range 4600-4800. Should I go up in pitch then lab to get rpms up or rework the 24. I have run a 21 pitch rev 4 which was a rocket out the hole 50 mph cruise 4200. WOT 4800 65ish. is there anything we can do on that prop to fix my cruise speed. By the way the 21 rev 4 came from you. A freind of mine purchased it from you. Thanks for your help.

A 23p mirage plus is what you want. Try it non labbed with the biggest vent hole plugs.

What is your gear ratio? The Rev 4 numbers look like they may not be quite accurate.

Labbing the B1 propeller will put you in the 4600+ range and should get you a 2-3 mph gain. The 24 B1 should have the better or at least as good of cruise speed.

A 3 blade prop dialed in will more than likely have the better top speed while the 4 blade has the low end and cruise speed ability.

Brett

I have a mirage plus 23p with the vents that I ran for about 2 hours that I would trade for your 24 bravo.

Thanks Brett for responding. I am running 1.5 ratio. I have also been told that the 3 blade props blow out to much on the step bottom donzi's and that they had a recall to replace the props. well anyway i will probably be sending my prop to you to get the blades labbed.

Is that typical of all applications? that a 3 blade would more likely have a better top end? Or just in this case?

Sorry for the delay,

It is the case in all cases where the 3 blade hooks up well (low slip #) and carries the boat well in the upper portion of the engines HP band.

Brett

Thanks for your reply. Then why all newest, hottest, fastest boats coming with 5 & 6 blade props?

Active Fun,

Ultra high X dimensions, great big HP can't be harnessed with most of todays 3 blade technology. Plus, the boat builders don't set the boats up that way or build them for 3 blades anymore. In the 6 drive applications there isn't even a 3 blade offering anymore. (I think there should be).

Likewise, a 3 blade boat set up correctly will typically slow down when you bolt on a 5 or 6 blade. due to drag.

If you read and decipher my post from prior, you will see I said a 3 blade will always be faster when it hooks up well and carrys the boat well. It comes down to the basic physics of less drag in the water makes you faster. This is why the 5 and 6 blades came to be. Builders found raising the drive decreased drag and picked up speed. As the industry continued to become over aggressive, we needed more blades to stay hooked up and even get the boats on plane. Weighing the set ups to the boat design determines the better propeller choice.

Put a set of 3 blades on the Geico Mystic and you have a issue. Put a set of 6 blades on my uncles Apache and you have another issue.

Still a 1 blade prop if hooked up correctly and without the terrible vibration, would be the fastest prop!

Have to take it in context.

Brett

Fixx
 

up the pitch of the rev 4,that prop seems to work the best on that hull.with your hp most guys run a 22 pitch rev 4.word of advise,ware your lanyard on that boat,they tend to spin out at higher speeds with + trim in turns so be careful..

theirs a 23p one forsale on donzi.net have brett lab it and enjoy..
http://www.donzi.net/forums/showthread.php?t=65067

Sent to get lab bed so I can try it!!!!!:evilb::evilb:

Need to send my 23p converted from b1 22p with cup too. It climbs out the hole good but 60 on top or 62 light sucks!! I think I need some more cup to carry bow but I'm perfect at close to 5 k loaded!! ????