Bravo 1 to XR shorty
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Bravo 1 to XR shorty
I just replaced the stock bravo 1 drives with xr uppers & 2" sportmaster shortys on my 34 Kachina. Although the power is still stock 496 mags right now that will change. I just was able to water test yesterday & there is a lot of difference. The boat took a lot longer to get on plane ( I expected some dif there) but also Im spinning 4900 to5000 rpm as opposed to 45 to 4600 before. I talked to BBlades last week & they said I might need to change from 28p bravo 4blades to a 27p 5blade. I intend to call again tomorrow now that its together, I just thought I would put this out here to get some comments or advice. Btw the gear ratio is the same & I also lost 10 mph according to gps. Thanks in advance.
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NO offense but you kinda did this backward. It's hard to know what a boat will like til the power is there. Real simple solution right now is to put the bravo 1 lowers back on. They bolt right up and are actually faster than the xr because of their smaller size. Once you get the power in than tune for props and see if the shortys work. They should be good for a couple miles an hour. As far as getting on plane your props are surfacing and caveating now so it will take longer. Adding a blade will help but will lose some top end with that power.
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Jpzaiuski, Thats cool nice to know I have an option but I like this boat. Twinspins, I was already thinking about that if all else fails. Poker-n-run, The reason I went this way is because I broke a drive at LOTO last year & was replaced with an older style drive (btw thanks guys you saved my weekend) So I wanted to beef things up a little before I go after more power, I talked with Brett at BBlades today & he figures aprox 24% slippage. I am going to try a couple of different props to see how things go. Brett also said I could go deeper with the drives to fix the problem so that option is still on the table
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With your power I would just go with the bravo lowers. You are planning to upgrade power so instead of dropping all that cash on props and then do it all over again later use what you have. Those shortys are sweet and sucks to see them sitting on the floor but you will gain a lot with the bravo lowers. too make them hook you will have to go to a big bravo 1 which you can't turn or a 5 blade that will cost u a pretty penny just to get you where the parts you already have will do.
My 2 cents but I have been there (;
My 2 cents but I have been there (;
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Randy,
Sounds like you picked up 300-400 rpms and lost 10 mph due to more prop slip. Before you started this project, did you record your baseline? Speed and rpms at different cruise speeds and wot.
The most important thing to remember during an upgrade or test period is to keep records for later comparison.
When do you plan to re-power?
My suggestion for now is to put your old drives back on and wait until you have the HP in the boat. After that, put the shorties back on and start there. You may want to also find someone to borrow some spacers from. Start with 1/2", 1" and work your way to 1 1/2" to find the best setup. You may find that if you are running under 80 mph, the Sportmasters aren't doing you any good. It would be nice to get a baseline with a pair of stock DWP 1 1/4" prop shaft lowers, before switching to the Sporties.
Props...Well, that takes time too! I think that 5 blades are fine for most XR applications. Drive failure related to 5 blade props is usually from abuse, holeshots, and driver error on exit and re-entry into the water. I have been running my 5 blades for the last 4 seasons with no drive issues on a VERY heavy boat. You can't beat the awesome cruise speeds and acceleration.
Good luck! Take your time and take notes.
Dave
Sounds like you picked up 300-400 rpms and lost 10 mph due to more prop slip. Before you started this project, did you record your baseline? Speed and rpms at different cruise speeds and wot.
The most important thing to remember during an upgrade or test period is to keep records for later comparison.
When do you plan to re-power?
My suggestion for now is to put your old drives back on and wait until you have the HP in the boat. After that, put the shorties back on and start there. You may want to also find someone to borrow some spacers from. Start with 1/2", 1" and work your way to 1 1/2" to find the best setup. You may find that if you are running under 80 mph, the Sportmasters aren't doing you any good. It would be nice to get a baseline with a pair of stock DWP 1 1/4" prop shaft lowers, before switching to the Sporties.
Props...Well, that takes time too! I think that 5 blades are fine for most XR applications. Drive failure related to 5 blade props is usually from abuse, holeshots, and driver error on exit and re-entry into the water. I have been running my 5 blades for the last 4 seasons with no drive issues on a VERY heavy boat. You can't beat the awesome cruise speeds and acceleration.
Good luck! Take your time and take notes.
Dave
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#10
I agree. Change your power, record your rpms and speed. Then, try the shorties. You'll more than likely change props. Work with Brett to see if a 4 blade or 5 blade works best. I found that the 5 blade hooked up better and gave me a little on top with Imco shorties. BTW, after 3 years I'm going through my first drive as we found metal in the oil.