prop help 2003 ZT230BR

[1972pontiac]

Hello all, my name is Danny, I need some help with the prop on my boat. I have a 2003 ZT230BR with a 350 in it. I had a 4 blade 21P prop on when i bought the boat and i was able to cruise at 55 mph but my rpms were only at 4200. I now have a mirage 19P and my rpms are at 5000 but i am only doing maybe 45 mph. What prop should i have on this boat?

 

[Craig]

Hello all, my name is Danny, I need some help with the prop on my boat. I have a 2003 ZT230BR with a 350 in it. I had a 4 blade 21P prop on when i bought the boat and i was able to cruise at 55 mph but my rpms were only at 4200. I now have a mirage 19P and my rpms are at 5000 but i am only doing maybe 45 mph. What prop should i have on this boat?

I think your tach is off. You can't go 55 with a 21p at only 4200. With 300hp I would think you could turn a 22p Bravo1 or 21 mirage plus either one, up around 4800-5000. 57-58 is gonna be your max speed with that boat/engine combo.

-Craig

 

[1972pontiac]

In your opinion, which prop would you put on the boat? A 3 or 4 blade? for best performance

 

[Craig]

In your opinion, which prop would you put on the boat? A 3 or 4 blade? for best performance

4-blade is best all around. 3-blade can be a little faster.

-Craig

 

[1972pontiac]

Okay thanks, i will try that and see how i do.

 

[1972pontiac]

I want to try a four blade prop, would a bravo I be the best choice or the evolution 4? The evolution has a smaller diameter

 

[Craig]

I want to try a four blade prop, would a bravo I be the best choice or the evolution 4? The evolution has a smaller diameter

Now that you mention it I did run a Rev 4 most of the time on the 230 I had with a 6.2. Bravos are slower out of the hole on small block boats. Try same pitch as any Bravo that works and the Rev 4 will be better all around and a 100 rpms more. Before the Rev 4 came out though Bravos were the goto prop on Persuaders and 230s.

 

[1972pontiac]

i did some researcha nd spoke to other people who have the same exact boat and motor and they seemed to all have used a rev4 21P for max performance

 

[flyby knight]

A Mercury Offshore/Vensura would also work.

 

[1972pontiac]

i have a rev4 coming tomorrow i am going to try and see how i do

 

[1972pontiac]

i tried out the prop and i was doing 50 mph with 4 people and a full tank of fuel. It showed my roms at 4000/4200

 

[Craig]

i tried out the prop and i was doing 50 mph with 4 people and a full tank of fuel. It showed my roms at 4000/4200

50 sounds about right for speed with that load. I still think your tach is off. For example my current boat is a ZT218BR w/ 350mag 300hp and propped to run 5000 rpms at WOT with just me in boat and runs about 66-67 mph. I add 3 more people and rpms drop to 4600 and 61-62 mph.

Now just going off memory I had a ZT230BR with 6.2 320hp and it ran around 60mph with just me and around 55mph with 4 people....23 Rev4 prop pretty sure ran the best on that.

-Craig

 

[1972pontiac]

Okay i understand, im going to try it out again one day this week after work by myself on a half tank and see what i get, i think you are right my tac is off. Overall i like this prop better i think it is the right choice

 

[smallblockford]

I have had mine since new I found 23 mirage plus to be best stock but something is off my boat is light I ran 67 with 3 people in it stock 300 hp 5.7 I am doing supercharger now it’s on I did many checkmates and was a dealer but my boat is very light I did 4 blades etc but for overall when stock I ran beat with mirage plus I think after super charger I will run hydromotive in 4 which I ran before or a bravo 4 blade but I couldn’t cary it or they help lift transom my 2 cents

 

[1972pontiac]

wow thats pretty good, my boat looks to have had some work done in the floor so maybe there is some extra weight there? Looks like the floor had been replaced with pluwood not treated correctly and then covered with vinyl flooring instead of carpet, i assume they all came with carpet floors? I am going to redo the floor this winter as its getting soft and ill see what i have under there. Stringers are all in good shape.

 

[1972pontiac]

i think a 23P would be to large for my boat if anything i would stay at 21P or go down from there.

 

[smallblockford]

You wanna be 5200 rpm light like just you in it so maybe 21 if she is heavier I have had my bought since new it was the 2008 catalog boat that is me and wife in it and lol I was driving the 30 to having a blast that day mine new came with 23 and could spin it I tried many others props that is

 

[smallblockford]

Pics of my boat

 

[smallblockford]

Boat has never been left out or in water over night even so it is dry and light

 

[Craig]

I have had mine since new I found 23 mirage plus to be best stock but something is off my boat is light I ran 67 with 3 people in it stock 300 hp 5.7 I am doing supercharger now it’s on I did many checkmates and was a dealer but my boat is very light I did 4 blades etc but for overall when stock I ran beat with mirage plus I think after super charger I will run hydromotive in 4 which I ran before or a bravo 4 blade but I couldn’t cary it or they help lift transom my 2 cents

Wondering why your boat would be any lighter? Not seeing how you are getting a 23p to run 67 unless you're talking speedo readings.

-Craig