Prop Suggestions
 

I'm looking for some suggestions for the next prop to try.

I just splashed my 1990 Baja 250ES over the holiday. (many thanks to all the OSO members who have helped with info along the way!).

I have a 454 MAG carburated with a Procharger kit, Stainless marine manifolds & risers, Corsa quick & Quiet Plus silencers, and MSD Ignition. I'm running a Holly 750 Nickerson carb and an Aeromotive boost referenced fuel system. Boost in the manifold was right on 5 psi @wot.

I borrowed a 25 pitch Mirage Plus solid hub prop and ran 77.4 mph on the GPS spinning the motor @5500 RPM (1.5:1 Bravo I). It was a bit of work to keep the chine walk under control but once I got the hang of it it was somewhat controllable.

It felt like there was definately more to be had if there was a bit more bow lift, and I'd like to get the rpm's back down around 52-5300. It certainly seems to have the power to turn a longer/bigger prop.

Couple of questions?
1. The 25P mirage plus was from a boat with alpha drives. Is there any difference between props for Alpha vs Bravo? It seemed to be a bit small (blade area).

2. I think I have read that Hydromotive QIV's are good at higher speeds. Comparisons between Mirage Plus, Bravo I, Hydromotive Intimidator? Either better for the chine walk issues?

The prop I ran was pretty good all around but had the tendency to blow out when trimmed up for speed. It also tended to blow out in turns at moderate speeds (40-50mph) unless the drive was brought in far enough to really drag.

Otherwise, I was thrilled with the boat and the Procharged motor! I just can't believe how well it ran out right out of the gate!:D!

The boat originally ran 62-64 mph (on speedo) so I'm pretty happy with the performance increase first shot out.

I'm thinking 26 pitch 4 blade. But I have always heard lots of good things about Mirage plus!

Any suggestions/guidence would be appreciated

thanks, Paul

I have a Bravo1 26 collecting dust in my garage, but my opinion is the Mirage+ is a great prop. Send it to a good prop shop to be tuned to your rig. They can make it hook a little better in turns also.

Fasterdamitt,

Are you running a Mirage Plus now? Did you run the Bravo I? I'm assuming if you are running a Mirage, you are running at least a 27 pitch. How did they compare on your rig? Are you interested in unloading the Bravo I?

Thanks for the input.

Paul

There are different diameters for Mirage plus props. I think 14.5, 14.625 and 14.75. If its a 14.5 then going to a 14.75 might drop the rpms a little and give a little more bow lift.
I think you're probably looking at a 26 Bravo 1 as the best option and maybe have some cup added to it to give more bow lift. It should drop the rpms by 300-400.
A Hydro Q-4 will give a lot of stern lift and push the bow down even more.

Griff,

Thanks for the info. I will check on the diameter of the Mirage Plus.

I am going to try and get my hands on a 26P Bravo I. Sounds like Fasterdamitt might be interested in unloading one.

I don't think I want more stern lift if that is a general characteristic of the Hydromotive props.

Paul

Hey paul there is a prop that is certainly worth trying out. Mark has a through hub 28 up there that is small diameter. I will also bring up my 27's for the formula this weekend and you can try them out. The more testing you do the better you should be able to dial in your final prop chouce when you have to spend money. The chinewalking and the speeds that you are now hitting it is time to think of external steering for that bad boy. Who would have thought you would pick up almost 15mph with that thing!!!!! :D:D

Jon

Nevrenuff,
No, I'm using a Mach cleaver 29, 4 blade on a 26' cat. I used the bravo1 26 before I built my new engine. The Bravo1 worked good but now I have more speed to produce more air pack under the boat. Therefor I can use a stern lifting prop. Yes, I would like to get rid of it so I can try a three blade for more top speed.

I had a 25 Checkmate, 502 with procharger and spun a 28p Bravo 1 @ 5000 rpm @ 78 mph. Great handling and reduced chine walk.

Hey Jon,

Bring on those 27's! Are they Mirage Plus?

Absolutely, I'm putting external steering in the budget for the winter work. I had no clue how to drive through the chine walk but Mark Gallagher took the helm from me and had the thing up on the pad as if it was his Hydrostream!

All I could think about was that gimball as he was yanking that wheel back and forth like a mad-man! I'm going to limit that activity for sure!!

Thanks and I'll see ya in Maine!

Paul

Fasterdamitt,

Has your Bravo I prop been reworked at all? What kind of shape is it in? How much would you be looking to get for it?

Paul