Bravo 1 HP limit
 

Looking to see what kind of max HP i can put on a 96 Bravo one, it's in a 25 elim. eagle. I'm currently at 500hp, may be going to 575hp.....

I have been told 600HP/TQ is about the limit. However many factors influence the life cycle of the drive. How heavy the boat is, aggressive planing, WOT RPM, hard acceleration from any speed, and prop leaving the water can all significantly influence premature drive failures. We are thinking of doing something similar to our 25ft boat w/ single B1. Some of the engine builders we have talked to mentioned it is just going to be a matter of time before the drive has to be inspected possibly upgraded. A 1996 B1 behind a 500hp is problably a little tired anyway. Go for more power and run the drive till she breaks. Everything breaks/wears out with time and stress. Your engine upgrade will just speed up the program.:food-smiley-007:

500 horse is already at or beyond. It's typically not some magical line where the drive grenades, but you're drastically shortening the lifespan of the drive. If you change oil very regularly, that will help. The cone clutch upgrade will help as well. Yearly disassembly for inspection and re-shimming will do wonders as well. 575 hp is going to speed things up a bit.

holeshots and jumps changes the picture substantially- now you are dealing with that 'magic line"

PM Articfriends, he has broken the most Bravo's of anyone I know on a light boat. I have 610HP in front of one but only a 2400 lb boat. No problems so far, but I don't drag or wave jump at WOT very often.

bravo one
 

I have about 650hp and alot of torque running a bravo one and have had no problems,i am not an idiot with it,but i do get on the throttle hard,i think it might be helpful to run royal purple in the outdrive like i do,maybe it helps alot.

I have called Merc. help line and asked the same question... Right from the factory guys mouth, he states 500hp on a bravo 1. I asked him about the XR, he states 600hp... I dont know what mods you can to to up the HP ratings but I'm sure there out there.

At least 2000 HP, ask tripple digits... :rolleyes:

You've gotten some pretty solid advice so far. The lighter the boat and easier you are on hole shots... both contribute to how long this drive will live. Royal Purple will definitely help.
Good Luck...keep us posted.

What usually breaks, the upper or the lowwer or both? I do change the oil often, but have been using the Merc HP oil. Is there any upgrade kits available for the drive that i can get? I've got all winter to come up with a plan. Motor is in pieces as we speak getting worked on. My boating season is already done.

The top will grenade. I blew up seven in three years before I went to B-Max I am over 700 HP and torque 4200 lbs. Like all stated before me it's a matter of time. You can upgrade parts and change drive oil every 25 hours but it still is a matter of time. 2 years with B-Max no sign of wear.
Bob

My bravo is the original drive off 1989 24' Arriva. I have changed the gear oil yearly, lubed the u joints as well and replaced the input shaft once due to getting in some sand and twisting it a little @ w.o.t. on my 650 HP motor five years ago. Same drive since 1989 on four motors. stock 330 HP for six years. 500 HP for another two years. 700 HP for three more and now 900++ HP blown 500CI. for two years with absolutely NO PROBLEMS! If you don't treat the boat like a dragster and are somewhat kind to the drive it will last! Going on 20 years now, same drive no major repairs and I've run it above 6200 RPM for somewhat extended periods with no failures. I goose it out of the hole once in a while, ski with it a whole lot, run it hard a whole lot as well. Yes, your Bravo will hold up! Be nice to it!!!!

If you have external steering it will hold up a lot better.
Without it you will have to replace the gimbal about every 2-4 seasons.

From 91-2006 I hit a bravo 1 with 500hp and 500ft/lb in about a 2500lb boat, and never broke anything but hammered enough play into the gimbal to replace it three times.

BUT as the guys above say I was "nice" to it.

Wanna do a quick check to see how worn it is? Go outside right now and grab the bottom of the skeg and lift up- Anything over 1/16" play is not good.

IF you keep it in the water/dont jump it, Id say you'll get 2-3 seasons before a rebuild with 575 on that heavy boat. I don't think you'll "snap" anything with 575 if you treat it sanely but its fast wear that's your enemy. Get a drive shower.

Good luck.

Uncle Dave

Laveycraft 2750 - Ilmor 710
Laveycraft 20.8 Sebring 406 SB
Fleetwood nitrous toy hauler
Yamaha raptor-700/Kawi-KFX 450
Nissan Titan

I've got a drive shower on it, and it has dual ram external steering, but i have noticed some slop up and down.

Better go get it checked out seasons winding down anyway (unless you live in so cal like me or florida)

You'd think Id remember what the spec actually is after replacing so many of them. (I dont do my own drive work & thats why they call it "dope")

Depending on whats wearing you may be able to shim it extending parts life before replacement- this kind of wear will get worse with added torque.

I hammered about 2" into one and was running way to fast to be without steering so long. Could have been catastrophic.

2 seasons ago I switched to a B-1 XR with an ITS steering system.

Uncle Dave

Laveycraft 2750 - Ilmor 710
Laveycraft 20.8 Sebring 406 SB
Fleetwood nitrous toy hauler
Yamaha raptor-700/Kawi-KFX 450
Nissan Titan

Is the gimbal bearing the shaft in the upper and the bushing in the lowwer?

What can i do to this drive to get me by for a season or two besides running Royal Purple and other than easy hole shots?

If it's got some hours on it, I'd have it gone thru & reshimmed by someone that knows what they're doing with high performance drives. Their inspection may turn up a yet-to-happen life-ending issue.

A drive shower and a billet top cap would go a long way too.

I've already got the drive shower on. But what is the billet top cap you refer to? How would that help? Thanks in advance for the info.

P.S. According to the oil thread a couple down, Royal Purple is not the best gear lub. Looks like the Amsoil Servere 75/90 is the way to go............??

The top cap is a weak area. It's where the bevel gears from the input shaft and the downshaft meet. The harder you push bevel gears, the harder they try to push away from each other. A heavier top cap minimuzes that deflection.

On oils, look up posts by "hydrocruiser" or PM him. he's our official oil guy. I was talking to the guys at Konrad and they swear by the Royal Purple. It's what ships inside their drives. They do primarily commercial and military applications and have a great warranty. I doubt they'd be skimping on oil.

Well, if you get time, check out the oil thread, it has a review about the drive lubs. The RP didn't do so hot..... I'll check out the top cap for sure. Thanks.

I've run only Quicksilver Premium for twenty years on the drive I described above. I wouldn't change for anything....

24' Arriva...what a great boat! Used to service one years ago for a customer. Great looking, decent price, fast hull.

Post a picture.

Surveys and different sorts of lab analysis are all well and good, but never a replacement for actual, statistically-valid data. No one of us individually could ever amass enough experience to have any true statistical validity. But manufacturers do. Whether it's Merc, Konrad or whoever, they not only know what works, they're compelled to live with the results. If one of their drive fails under warranty, it's money out of their pocket for the repair and in some cases, it's a damaged reputation with an entity or community that is a multiple-unit purchaser of your product.

Konrad, for example, sells the majority of their equipment to government agencies and the comercial market. Problems with these customers become very expensive- especially if your product garners a history of failures.

In the example of Konrad, they feel confident enough with the RP to put their $$ on the line. And it's not to save a couple bucks on oil. Same with Mercruiser.

Does anyone run the Amsoil severe geal oil?