bobd

2003 baja 342 twin 496 ho just rollerized them bravo xr 1.5
sits on revlimiter all day with stock 26 p bravo1 4 baldes
tried a freinds 30p 4 baldes 70 gps at 4600 3 guys fulltanks
want to run 5000 rpm its good out of the hole with the 30s
lookin for 74-75 top what do u guys recomend

throttleup

I would recommend 5B props for your application. The Hydromotive P5-X props work very well on the Baja's. Dialed one in on Friday he went with 25P P5-X RH & LH for his 34!

Julie

bbladesprops

I definately would not recomend 5BL props. Your slip percentage is high. The 5 BL prop would be a band aid. They would decrease the slip but add too much stern lift at WOT.

We could Lab your 30's and get the r's to 4900 and pick up a couple mph. But I would concider checking the relation of the prop shaft to the bottom of the boat. You may be able to drop the drives slightly to decrease the slip, leverage the stern to carry the bow and have 4 blade props deliver the best top end.

throttleup

Agree to disagree Brett. The Hydro P5-X props work well on this boat. But a 1' inch spacer would't hurt at 17% slip. Keep in mind that if you consider a spacer you should do you propeller dial in work after the matter. Labbing your 30's will simply exacerbate your issue.
Julie

bbladesprops

Well we do agree to disagree on this one. That's good, it causes us all to think out the situation. After over a decade of dialing in Baja's, one thing I know is that they like allot of bow lift.

You can tell me till your blue in the face the P5X is a bow lifting propeller. It's not. As far as a 5BL is concerned, it will pull the stern down slightly creating some bow lift because of the built in rake and round ears. But only after it has lifted the entire stern up. If the depth of the drive allows the prop to leverage the stern at this point, it may carry the bow a little. LESS blades MORE bow lift. The nature of the P5X and the Maximus 5BL are that of really showing their stern lifting characteristics at WOT. That's why they don't normally show top end gains (unless the slip is through the roof on Bajas). In addition, they have more drag (more metal in the water). Boats that fly the bow and have med to high slip will pick up on the top with these. Also race boat set ups can archive great throttle response. Not necessarily the best top end #'s though.

Don't get me wrong, I think the P5X is an awesome propeller! So is the Maximus! They just aren't always the best choice.

In this situation, with the high slip of close to 18%, it's easy to throw a 5 blade prop at it and improve the performance across the board. But ultimately the boat is set up wrong to begin with. The slip issue should be addressed before propping. Maybe the 5BL will be what bobd wants after all?!

If you re-read my last post, you will notice I said we "could" Lab the 30's and gain rpm's and most likely, even though the slip may change, the speed would commonly go up slightly. This was said since bobd wants 5000rpm. That was an option followed by.....consider lowering the drives first to combat the slip %. This may then allow the 4BL's to be the fastest top end propellers. I still feel the 4 blade will out run the 5 blade on this boat if set up correctly. The 5 blades will definitely help you throughout the low to mid rpm range.

Good luck!