Bravo derivative to handle 750HP
#81
#82
Gold Member

Joined: Jul 2008
Posts: 3,748
Likes: 869
From: Delray Beach, FL
#83
The flexing of the gearcase prevents using a higher diametral pitch.
You want to run more than 500 horses thru a Bravo style drive, get a Bmax or SCX, have it set up properly, and realize that it is still your weak link and treat it as such.
There's a reason why Merc stops selling Bravos above 600 hp.
If you like idling back on one engine, listening to your tunes, getting sunburned, and smelling gear oil, then that's completely up to you.
MC
#87
Registered
Joined: May 2011
Posts: 325
Likes: 0
From: Jupiter, FL
Hey guys,
I have a similar question not to hi jack the thread but we are building a 30' velocity race boat to race at 90mph, building 600-650hp BBC's, was going to go with bravo ones or a bravo derivative but cant seem to spend $14k per side for a bmax or SCX, was thinking Arnesons conversions but been watching the other boat in the same class and they barely finish a race due to Arneson breakage, which leads me back to a Speedy but do not like the idea of the hp robbing tranny, was thinking about bravos with maybe XR uppers and speedy or scx lowers blueprinted but not too knowledgeable on bravo ones or their derivatives, what do you guys think the ultimate setup would be? We are looking mainly for reliability so if we have to de-tune to 600hp we will sacrifice some hp for reliability as our main goal is finishing the race. Thanks guys.
I have a similar question not to hi jack the thread but we are building a 30' velocity race boat to race at 90mph, building 600-650hp BBC's, was going to go with bravo ones or a bravo derivative but cant seem to spend $14k per side for a bmax or SCX, was thinking Arnesons conversions but been watching the other boat in the same class and they barely finish a race due to Arneson breakage, which leads me back to a Speedy but do not like the idea of the hp robbing tranny, was thinking about bravos with maybe XR uppers and speedy or scx lowers blueprinted but not too knowledgeable on bravo ones or their derivatives, what do you guys think the ultimate setup would be? We are looking mainly for reliability so if we have to de-tune to 600hp we will sacrifice some hp for reliability as our main goal is finishing the race. Thanks guys.
#88
Find out what they are breaking. They may have tiny Arnesons that aren't rated for the power.
The transmissions that are used in a typical Arneson setup (trans inside boat) are capable of handling up to 1200 hp with the correct upgrades.
The trans used in the extension box ASD-6 Bravo conversion kits is rated at 750hp. That matches the rating of the Arneson units themselves.
The transmissions do eat a little hp, but not as much as you lose with two right-angle sets in an outdrive.
If you are racing, dependability is paramount. If you have the correct Arneson setup matched to your hp and torque (properly installed and setup), then you have a reliable driveline. If you pump 650 hp into a Bravo, you never know whether you get towed in or finish the race under power.
But choosing a "too small" Arneson will result in the same aggravation as you get with too much motor into a Bravo.





