3 Blade or 4 blade Prop?
 

I am running a 23P Mirage Plus on a 25 ft Outlaw 454MPI/Bravo 1. I get 70 at 5000RPM's with lot's of gas and a full boat on the Speedo. BEst yest is 74 with just me and low fuel.

Will I gain anything by going to a 4 blade Bravo 1. My hole shot is OK, could be better with a tuber. I am satisfied with my Top end.

I am asking as my other boat is boning out and I need to use the Baja for a time to pull the kids.

Will I get any benefit?

Re: 3 Blade or 4 blade Prop?
 

The 4 blade should bring you out of the hole a little quicker if you don't over prop but you will drop a mile per hour or two on top.
While you are tinkering you might check your speedo, I think it is off at least 5mph maybe as much as 10. I don't have an Outlaw but I think a 25 with a 502 is a 65-67 mph boat. Unless you have a great running 454 you are going to have to shave a little off of that.
Sorry, just my thoughts. :D

Re: 3 Blade or 4 blade Prop?
 

boatfreak,

I appreciate the feedback. I do plan to get a GPS, but I have run with some other boats claiming those speeds and stayed with them? The Merc Prop Calculator says I should be getting 66

I have 385 HP. Some 454's only get 365 or 375. I think some 496's actually get less, like 375. The deal is this, the speed is nice, but I ain't crushing any waves, so in my eyes, it's not just how fast, but how fast in the rough!

Re: 3 Blade or 4 blade Prop?
 

Here is a web site for an automated prop calculator. I tend to agree that you are most likely going about 60-63 MPH because with 10% slip it says 65 MPH and a vee bottom baja has More like 15% slip at best. And you maybe at 18% At 15% slip it says you are going 61.7 so you need a GPS spedo.You can only achieve 10% slip with a 4 blade and an efficient hull like a cat. Check out the web site it s

http://www.rbbi.com/folders/prop/propcalc.htm

I have a friend with a 272 Baja with a 502 MPI and my boat has a GPS spedo so he asked me to clock him and it
was 60 MPH on the nose and his spedo said 67 so water pickup spedos are very generous to make people happy.

Bye the way if you do go to a 4 blade you will need to go down in pitch for sure to a 22 but I do not think you will be able to turn it 5000 rpm. maybe 4800 rpm.

Good luck

Re: 3 Blade or 4 blade Prop?
 

NJ Dave,

Thanks. I just talked to Curtis Propeller. They suggest a 22 also. He said it will be about the same RPM's.

Now the question is do I want to lay out $400+. Decisions decisions

Re: 3 Blade or 4 blade Prop?
 

My last 3 boats had speedo's that were all 7mph off. When i had friends on the boat i would leave the GPS off so it looked like i was going faster. :D

You will get a better cuise and handling with the bravo, but top speed will suffer a tad as stated above by boatfreak. Best thing to do is borrow one before you buy one.

Re: 3 Blade or 4 blade Prop?
 

A friend of mine has a 2001 25 outlaw with the 502 MPI. He only see's 64mph on his good days.

Re: 3 Blade or 4 blade Prop?
 

a 4 blade bravo 1 prop will be better for pulling, it will have less slip than the 3 blade prop, if the 3 blade is working ok for pulling skiers, ect. then save your cash, also the 4 blade will have about 2 mph less top speed

Re: 3 Blade or 4 blade Prop?
 

$400 is about the cheapest thing you will ever be able to buy for your boat. if you think thats steep, much awaits you :cool:

Re: 3 Blade or 4 blade Prop?
 

Talk to Darin at Houston Propeller. He is an expert with Mirage props