what prop nexted
 

HI ALL , to day I got some good #s finely 5600rpm 26b1 labbed baja ol 24 4000lbs 2'' shortie 380s kplanes on #6 to 7, 2 to 3 foot chop that I got the repeat speed of 83.2 gps on the flat water I was getting 80 to 81gps trimed up alot I think ,so should I go to a 5 blade for more speed and bow lift or stick with a b1 28 labbed for more bow lift, what is my slip with the b1 26, 5600, 83, 1.5gear? thanks

Re: what prop nexted
 

I would be interested in the 26 Bravo if your thinking of selling it.

Re: what prop nexted
 

what motors? what r's are you making peak power at? it is rare that a 5 blade is fastertop end then the 4 blade bravos. dont know the formula but your slip #'s seem decent?

Re: what prop nexted
 

sorry...above post was supposed to be for air time

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motor was a merc 510 647hp at 5900 I THINK, DON'T HAVE THE DYNO SHEET ITS AT NICKERSONS AND TQ WAS627 AT 4800 THAT WAS WITH OLD CARB 850 BG WITH 82/82 JETS THE OLD SET UP i WAS HITTING A WALL AT 5100RPM ONLY GOT 74 OR 75 MPH.

Re: what prop nexted
 

AirTime,

I have calculated your slip at 5% ....but unfortunatly it is not likely that 5% is accurate. The range on a 4B is 10-14% and typically Vee Bottoms are not less than 5-6% with 6B props. So I would recommend that you verify your data so as to not chase any ghosts.

Julie

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so the gps could be off that much? 2 weeks ago with 100gals I goy readings of 78gps and on the river yesterday in the flat for a hour up and down I WAS GETTING READINGS AT 1ST OF 79 TO 80 then I went out to the bay where after a while I got readings of 83.2 83, 82 ran from one end to the other I was sitting in the bolster so the tach reading might of been 5800? on the river I was standing and the tach was at 5600 with the 79 to 80gps. well going out on sat and will have a rider hold on to the hand held gps, and I will watch the gafrig dash one. going to check the gas tank sender to day so I will know if IO am running low. this is a labbed 26 not sure if was made to a 27 either it was done back in 2002 a 28 was to much back then. drive was to deep.

Re: what prop nexted
 

I think it is a good idea to verify tahcs and GPS's. Is there a strong current in the waterway that you boat? If so this could accopunt for things as well. Let us know what you come up with this weekend.

Julie

Re: what prop nexted
 

I calculate your first readings more in the 7% range. The efficiency drops as the speed does. The slip then goes in to the more common 10-11% range.

We see many boats run under 10% with 4 blade props. However, very few are Bajas. Going to a 5 blade on your application will most likely not improve the top end numbers. We can test with them if you like.

Labbing the current Bravo 1 props to get into the upper 5000's is a likely option. The Labbing would need to be done to fit your specific needs. Let us know when you get the most accurate numbers.

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I will be going out sat and will bring hand held gps too.no one on this site has ever run a ol 24 with the 2'' shortie ,the prop shaft and the pad is 5 1/2 '' and the prop was labbed back in 2002 .I TALKED TO ONE PERSON THAT HAD A 1'' SHORTIE RAN 1300HP AND DID OVER A 100 AT LOTTO SHOOT OUT A COUPLE OF YRS AGO. OH well at lest its faster than last yr74 at5100 whats the slip for that or what the cal?

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there's a 25 ol with a box getting 81mph at 5300rpm what is his slip # prop is a b1 28 at 300more rpm 26 I would think would be at 81 or 5700 or 5800 be 83 what is the cal you use to find the slip? thanks art oh his is raised 3''

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I tried a 28 5 blade maximus a few weeks ago,boat went another 1 mph slower on top end,stern lifted and bow steered,plus sheared off a prop shaft.You would probably be wasting your time unless you get one really worked on and have alot of time to have it modified,test,modified,test,re-test etc. It did have excellent cruise though,Smitty

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In general 5 blade props aren't the answer to top speed on deep V's. I have been telling people that for years. There are exceptions to every rule though. Bajas with higher X dimension from shorty case with big HP can obtain a high enough running attitudes to not bow steer with 5 blades. We do also adjust the diameter to help the overall running attitude. The correct 3 or 4 blade propeller on a Baja is still the recommendation for all around performance.

There are many reasons a prop shaft can break. Just bolting on a 5 blade propeller isn't one of the main reasons to loose a prop shaft.

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Boat was straining hard from 4800 to 5700 with 28 pitch 5 blade maximus,taking 3 times longer to pull the rpm's than with a 30 labbed,i think it just pushed the shaft past its limit when I was prop testing. What I think is shaft was at 95 % of its limit with the big tq and running my 30 and 32 labbed props,the 28 5 blade slipping signifigantly less put it to the failure point,it might have just been coincindental but there are no more 5 blades in my future :D ,Smitty

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81 at 5800to 5900 flat water in the bay and river river 80 to 81 up and down my buddy was cutting his lawn 2 miles away he could here me on his lawnmower :eek: and I ran 10 passes easy :p :D love MY dry S/M :p :p LOOKS LIKE A 28 5BLADE this winteror 28/30b1

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all set thanks bblades good talking to you .