Superchargers and outdrives
01-19-2018, 07:37 AM
#21
Platinum Member
Platinum Member
iTrader: (6)
I've been running 700 HP through a pair of bravos for about 500 hrs. The drives are original circa 1992. Over 1100 total hours on the drives, never opened up. I'm easy on and easy off and it I air it out it's not intentional. Don't get me wrong, I use every bit of power I have and I beat on it when someone makes me do so. It's all up to how you work the throttles.
.........and second Im shocked 800hp is breaking a bravo....
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01-19-2018, 08:31 AM
#24
Registered
Nothing looks better than a carbed roots blower motor IMHO. Well maybe a giant PSI carbed blower motor but that’s it. Good choice sir!
01-19-2018, 10:31 AM
#25
Registered
When I had my blower boat I was always easy on the sticks getting on plane. This is a lot of load on your drives and where you are most likely to break them. I never had any issues but I also had Teague Platinum XRs as well.
01-19-2018, 10:58 AM
#26
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iTrader: (3)
Plus the concept of being good on the throttles, can vary. It' easy to work the throttles when you're jumping over a random wake from a cruiser that you encounter a couple times a day while boating. Not so much when you're on the ocean or great lakes, and your on/off the throttles every 4 seconds for 30 plus miles at a crack. High x dimensions and rough water is the number 1 drive killer in my opinion.
01-19-2018, 11:59 AM
#27
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iTrader: (4)
If you are going to run big power, and currently have bravo's, saye your money to convert them to IMCO SCX uppers. To save some money, you can run an IMCO SC lower. Here is the deal with Bravo's.
There is a lot of smoke and mirror sales guys out there. Special shafts, coated gears, better bearings, it goes on and on. NONE of it, is going to do much if anything, OTHER than drain your wallet. The clutch shaft is a major weak spot in the bravo drive, and there is nothing you're going to do to improve that. Steel towers will help keep everything lined up, BUT it won't fix the issues. Mr. Gadgets in my opinion, has the best tower upgrade for the money, so be wise when spending your money, but it has its limits as to what it will do.
What I would suggest is keep your eye open for a nice set of IMCO SCX drives. They pop up from time to time, and they will handle the power you will be making. I've seen them as low as $7k ea, which isn't a whole lot more than a rebuilt bravo XR. Speaking of XR's, 200 hours on an XR, and its most likely due for new gears, at $1600 plus labor. Again, if you're planning on new power, start saving for new drives, and don't waste a penny on making your bravos "better".
There is a lot of smoke and mirror sales guys out there. Special shafts, coated gears, better bearings, it goes on and on. NONE of it, is going to do much if anything, OTHER than drain your wallet. The clutch shaft is a major weak spot in the bravo drive, and there is nothing you're going to do to improve that. Steel towers will help keep everything lined up, BUT it won't fix the issues. Mr. Gadgets in my opinion, has the best tower upgrade for the money, so be wise when spending your money, but it has its limits as to what it will do.
What I would suggest is keep your eye open for a nice set of IMCO SCX drives. They pop up from time to time, and they will handle the power you will be making. I've seen them as low as $7k ea, which isn't a whole lot more than a rebuilt bravo XR. Speaking of XR's, 200 hours on an XR, and its most likely due for new gears, at $1600 plus labor. Again, if you're planning on new power, start saving for new drives, and don't waste a penny on making your bravos "better".
01-19-2018, 12:23 PM
#28
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iTrader: (3)
I agree on the scx. Except I think I would opt for the scx lower as well. My buddy Joe had scx uppers, with sc lowers, on his 42 fountain with a pair of 1000s. He sold the boat with very low hours, like maybe 10-20 hours on the new engines. I think the sc lowers were as fresh as well, and they new owner took the lowers apart and they were shot. Both lower gear sets that is.
I think the reason the #3,4,5,6,8 drives handled power well, was because they had two gearsets in the lower. Each driven by it's own vertical shaft. Putting all that torque thru one gearset that has to be small enough to fit inside the bullet, is just not strong enough for today's engine. This is also why the power handling capability of a speedmaster drive, can be immensely reduced if set up by someone who isn' familiar with them. If each lower gearset assembly isn't setup so that power gets split equally to both sides, they will fail prematurely.
I think the reason the #3,4,5,6,8 drives handled power well, was because they had two gearsets in the lower. Each driven by it's own vertical shaft. Putting all that torque thru one gearset that has to be small enough to fit inside the bullet, is just not strong enough for today's engine. This is also why the power handling capability of a speedmaster drive, can be immensely reduced if set up by someone who isn' familiar with them. If each lower gearset assembly isn't setup so that power gets split equally to both sides, they will fail prematurely.
01-19-2018, 12:29 PM
#29
Registered
Plus the concept of being good on the throttles, can vary. It' easy to work the throttles when you're jumping over a random wake from a cruiser that you encounter a couple times a day while boating. Not so much when you're on the ocean or great lakes, and your on/off the throttles every 4 seconds for 30 plus miles at a crack. High x dimensions and rough water is the number 1 drive killer in my opinion.
01-19-2018, 12:48 PM
#30
Registered
iTrader: (4)
I agree on the scx. Except I think I would opt for the scx lower as well. My buddy Joe had scx uppers, with sc lowers, on his 42 fountain with a pair of 1000s. He sold the boat with very low hours, like maybe 10-20 hours on the new engines. I think the sc lowers were as fresh as well, and they new owner took the lowers apart and they were shot. Both lower gear sets that is.
I think the reason the #3,4,5,6,8 drives handled power well, was because they had two gearsets in the lower. Each driven by it's own vertical shaft. Putting all that torque thru one gearset that has to be small enough to fit inside the bullet, is just not strong enough for today's engine. This is also why the power handling capability of a speedmaster drive, can be immensely reduced if set up by someone who isn' familiar with them. If each lower gearset assembly isn't setup so that power gets split equally to both sides, they will fail prematurely.
I think the reason the #3,4,5,6,8 drives handled power well, was because they had two gearsets in the lower. Each driven by it's own vertical shaft. Putting all that torque thru one gearset that has to be small enough to fit inside the bullet, is just not strong enough for today's engine. This is also why the power handling capability of a speedmaster drive, can be immensely reduced if set up by someone who isn' familiar with them. If each lower gearset assembly isn't setup so that power gets split equally to both sides, they will fail prematurely.
