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I researched this for a bit but couldnt find anything.
I have a Z302 WOT is 4500 and MPH is roughly 45mph
I have the SS Props i will post hopefully tomorrow the pitch.

Question is it worth going to 4 blade or should i stick with the 3 bladed props but change pitch?

I want more top end.

First off, we need to know what engine you have since that's what determines where your recommended RPM's should be. In looking thru your profile i see a 7.4 which has a recommended rpm range of 4200-4600 at WOT. You are in that range now. Second, we need to know what pitch props are on the boat now.

Now if you searched & didn't see my two sticky's right at top of this Prop forum, you should read both of them first.

As a quick answer to your question, going to a 4 blade will not increase your top end. Any increase in prop pitch might give you another 1-2 mph but there is a good chance your motor will not run in the recommended range. You can read about the effects of pitch change in those stickys.

One thing you could consider is installing a pair of Smart Tabs. Another of our Z302 owners (oregondunes) installed a pair and i believe he liked the performance results. They wont necessarily make your boat go faster but they will get it onto plane quicker and hold in on plane at lower speeds.

I'm gonna assume with 4500 rev limit you have 310/330 hp 454 mpi like I used to have and a 2:1 bravo 3. Probably have 26p props too (maybe 24's). If so, your stock motor will pull the 28's but not well out of the whole. You will have more slip until you can spin the props over 5000.

Btw.....love the smart tabs

Once I figure out engine gremlins, I'll let know of my drivetrain changes and their effect. I'm using a 2.2:1 ratio drive and a pair of brand new labbed 28's.

Bigger wheels and a higher ratio. Rev limit is set to 5500

Thanks so much for the advice,

BTW yes i have the 7.4gi 310hp

Im gonna take a look at the boat tomorrow and find out pro sizes and ratios and all of the technical specs.

My normal drive is a 2:1 and I'm hoping with my new engine I can pull the 28's with ease

Yeah thats right you got a new fresh built motor. I really wish there where things i could do to this volvo to get another 50 to 60 hp out of it, but since there isnt i have planned to swap out for a 540 during winter and a bravo3x

Only way is to replace or build up from scratch. Blower will only blow it up for good

Quote:

Originally Posted by Oregondunes (Post 47139)

Only way is to replace or build up from scratch. Blower will only blow it up for good

Yeah thats what i figured, im just trying to do a temporary fix, until then. What kind of trim tabs do you have, im about to order some benetti trim tabs

Quote:

Originally Posted by luke7575 (Post 47141)

What kind of trim tabs do you have, im about to order some benetti trim tabs

Smart Tabs. They work for all that I need em for. Until you get your boat up and over 60-65 mph, smart tabs helping you to plan at slower speeds and getting up quicker to plan is all that matters.

OK finally got the boat back, from getting the captains call rebuilt, and the Drive ratio is 1.78 and the are f6 props