hp limit on a stock bravo I drive

[DonZi 26]

ok lets talk.....

whats the outmost max hp that a stock bravo I drive can handle ??

i've heard some say that they have over 700hp with a stock bravo I and run smoothly, but take very good care of it....

what you think guys ?

[Donziweasel]

rated by Merc for 400, but can take way more than that. It is more about how the drive is treated and how you drive the boat than it's rating.

[Carl C]

Mine lasted several seasons running hard with the 496 HO. The 525 EFI broke it in 7 hours.... The XR/Imco shorty has now lasted 2 seasons.

[BlownCrewCab]

We have done 650hp and raced it (offshore) for a year or more. Yes you need to be consious of prop speed when the prop is going in and out of the water allot. The newer Props make it harder on the drive since the props bite so well. (example) your drive will last longer with a 3 blade than a 4 blade since a 3 blade doesnt bite as much.

[The Hedgehog]

Ran 600 or so through one for a couple of seasons. No problem. It never broke

[osur866]

I'm hoping mine will handle, just shy of 600 HP, think it not only depends on how easy you are on the sticks but also the weight of the boat, 600 HP in front of a Bravo in a 2800lb boat I think will live alot longer than the same HP in say a 6000lb boat driven the same. Steve

[Dr. David Fleming]

Good question about Bravo I strength. I notice the Bravo appears in Merc advertising in 1988 after a year or so of 454 Big Blocks built with the Alpha drive. Then it runs through production to today - that is a long time!

Looking at several of these drives I see some advertised variations -
"Bravo I" and "Bravo I Performance" are two of them. Some Bravo I drives have water pickups on the sides of the lower and use an "ear muff" water hook up, and some have water intake in the bullet nose and use a "muff" water hook up.

All these drives equal in strength? and performance? Boat mechanics seem to consider them the same. Examination of the repair manual shows many special tools and a fairly advanced procedure.

My effort to get Tyler Crockett to talk about Bravo I resulted in his opinion of it as a "fast" drive through the water for stock 400 - 500 hp engines - with need to limit the prop loading on it.

He had a real beauty all tore up when someone in an alcoholic induced stupor revved up his Whipple charged 502 to about 5000 rpm and then decided to drop it in gear - twisted the U joints all apart shattered the bevel gears - yah! even though it drives into water you can't pull a hole shot like that.

[osur866]

Side note, I'd say not all Bravo's are equal, I've been told the newer "Swept Back" Bravo's use the same upper gear set as the Bravo X drive only difference between the X and reg. Bravo is the top cap in the X has a steel tower. I know a cpl people pushing 600-700 Hp thru a standard Bravo without problems, and then again I've also heard of a few tearing up XZ's and XR's with less than 525hp so, I still think it comes down to a combo of things, how it's driven, weight of boat, and if your using 3, 4, or 5 blade props. My .02

[The Hedgehog]

I'm hoping mine will handle, just shy of 600 HP, think it not only depends on how easy you are on the sticks but also the weight of the boat, 600 HP in front of a Bravo in a 2800lb boat I think will live alot longer than the same HP in say a 6000lb boat driven the same. Steve

Unless you are one of those that spends more time above the water than actually in the water I heard that you drove it like you stole it around LOTO on Shootout Weekend. The guys from Nashville were pretty impressed.

[osur866]

Unless you are one of those that spends more time above the water than actually in the water I heard that you drove it like you stole it around LOTO on Shootout Weekend. The guys from Nashville were pretty impressed.

Well Bill you will need to see first hand next year

[VetteLT193]

It is mainly going to end up in how you run the boat. If you like to run hard, fast, and long... it won't last long so get a better drive. If you are gentle on it no problem.

[DonZi 26]

ok how im gonna run over 600hp on a stock bravo 1.......


boat is a donzi 26zx and they say it weighs about 5800lbs...

now we'll see how it goes hopefully it will last long enough, it has less than 150hrs on it....

[mike o]

I'm hoping mine will handle, just shy of 600 HP, think it not only depends on how easy you are on the sticks but also the weight of the boat, 600 HP in front of a Bravo in a 2800lb boat I think will live alot longer than the same HP in say a 6000lb boat driven the same. Steve

Doing a little upgrading are ya.....

[osur866]

Maybe, we see. It's always a LONG winter ya know!

[Dr. David Fleming]

Just ran across July 2010 Performance Boats article by Tyler Crockett,

"I wouldn't be worried about beefing up a Bravo to run behind a 650hp. You just need to take it easy getting up on plane and roll into the throttle easy when you accelerate, and you should be fine. One thing that is important when you do decide to rebuild a drive is that you have the steel tower machined into the upper case to suppoort the upper gear set. There are several tricks to building the drive, such as using the bigger prop shaft and treating the gears to make them stronger. Also, make sure you install a drive shower to help keep the upper cooler, as it is out of the water when you're running. They also have stud kits and stronger top caps to put on the drives too."

In another discussion Tyler talks about running 1000hp into a Bravo,

"We have built several Whipple 540s that made 950 to 1,000hp without any trouble...Your next issue will be the Bravo drive, and keeping it in one piece. We have had several customers running big power and torque on the Bravos, but their time has been limited. I have a customer with a 28 Eliminator and watched him go through three drives each summer - until we put a Imco SCX drive on. How he has run two seasons without a problem. He did loose about 2-3 mph with the bigger drive, but he gained reliability, which is a plus."

It would appear that the Bravo drive starts getting touchy with 650hp and is over its head at 950hp. Except for Carl C - 540hp for him! Also it would appear that a stock drive Bravo is fast.

Wonder how Tyler would rate one of his rebuilt Bravo drives with big prop shaft, heat treated gears and steel tower and cap with studs against a Bravo XR or the Imco SCX - 2-3 mph is significant to some.