Prop Recomendation for Donzi 38zx (Daytona)
 

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I had my props stolen this winter for my Donzi 38zx Daytona, and have been in the market for a set since then. I have gotten several recomendations. Hydromotive has suggested the p5x 26 pitch, as well as Teague Marine. With my old Bravo I's 28 pitch, I was only getting 4800 RPM's and top end speed of 73-74 GPS. I have been told by Donzi I should be around 80 with the RPM's at 5200-5300. I then spoke with Bronsonhill out in CA and they were telling me I would get slower speeds with the p5X 26 pitch. So now I am a little uncertain what direction to go.

Thanks for the help!

Your hull can be very touchy to Lab finishing changes. However, your efficiency with the old props is fine for your hull. Therefore, I would Lab the 28's in the proper recipe, hit 5000 rpm and be happy with 77 mph.

5 blade props will not add mph in your situation.

Thanks for the recomendation.

I run Bravo I's - 26 Pitch - and run 78-79 MPH around 5200-5300 RPM. Hope this helps. Ted.

Freshwater or salt ? What engines do you have, and what year. Daytona package(extension boxes) or std ZX. This does help. I have a buddy that has the same props. I am going to be testing them this weekend. and will let you know.

Thanks for the help.

Brackish water - Upper Chesapeake Bay.

500EFI's

Standard 2000 38ZX - A/C - No Gen

No Extension Boxes

very helpful. I am going to test them out this weekend.

Thanks for the help !

I spoke with alot of 38ZX owners when I was shopping for my 38ZX. Most owners were claiming upper 70's. Even the newer ones with 525's were getting close to 80. (Not a huge performance difference from 500's to 525's) One Daytona owner with 600 Innovations claimed 86 MPH. Another one in Florida I looked at with 750HP Sterlings reached 90 MPH.

Your Daytona should be a solid 80 MPH in my opinion.

Let us know how you do. Ted.

i run 66mph max with 28p 4b props with 500efi at 5000rpm does this sound right with a few people and close to full on fuel (200gallons)
i just got the boat a few weeks ago and only had it out twice...i thought it would be faster

Fixx
 

keep in mind, the p5's will cut your fuel consumption down as well as long as you keep the boat in its power band..may not be as fast but will help with the fuel cost..

Bringing this back alive.

I have an 02' 38ZX
Twin 500EFI
Standard Bravo 1 26P. (Brand New)
Freshwater
Max RPM 5000
Max MPH 67

Need some help. I feel like I should be hitting 75mph.

Hello,

We have sold many P-5 X's to Donzi owners with your boat and motor package The feedback has been excellent as to better top speed, better cruise, and good hole shot. When you lab most Bravo props in 2 " higher pitch, and lab to gain 200-300 rpm, you lose mid range cruise speed. Sometimes it also hurts your hole shot. The reason is the reduction in cup among other things, which increases rpm at expense of added slip in the mid range.

I will be happy to discuss this with you. Please call.

JcookMI,
Your slip % is 16%. A touch high but not too bad. When you adjust the recipe on Labbing Bravo 1 propellers you can decrease the slip numbers and still gain rpm. Granted you may only gain 100-200 rpm but in this case that should be fine. We have dealt with these issues for years and have developed Labbing recipes that go beyond the old standard methods. We also do all our Lab Finishing in house rather than farming it out so we are developing new recipes constantly.
5 blade props are also a option. P5X props are a good choice for better planning and a touch in the middle. However, better top speeds out of a 5 blade will require Lab Finished 15.25" diameter Maximus props. In that case the potential for 70 mph exists.

Brett

Thanks for the tips everyone. I'm nearing the time the motors need to be refreshed.
I'll likely wait and see how that changes my slip %. Wouldn't be worth changing props now, then changing all the parameters.

Cheers
Josh

I'm having the same issue, and I'm running 26p props with 500EFI at roughly 5000rpm.

Typically refreshing the engines won't change the slip #'s.
Call us if you wish to try any of the props that have been recommended to you.
Have a nice weekend!

Brett

38 zx with twin 525
 

the 32 x 4 was 4900 rpm ... we need to play with trim and also opposite rotation to see what the boat wants with that -1 lower