Upgrading From Bravo Xr To...????
 

I am currently running Bravo XR drives with IMCO -2 lowers on a 35 single step Fountain Lightning that I just purchased.

The boat currently has big power (850 HP) and I keep snappling the verticle shafs in the drives (three times this season). I am currently looking at de-tuning the motors to try to avoid this problem (changing the blower pully and turning the power down to 650 HP).

Is there any option to upgrade the drives to something else that can handle the power and not cost me an arm and a leg? If not Ill be looking for a new boat in a couple of months.

Call John P at the Bravo Shop and see if he can help you out. He's been working on improving all the shafts in the bravos 402-297-7977

I'd rather break shafts than gear sets......that bing said, call John @ the Bravo Shop. He really has some talent for making things that should be right, correct.

Currently running IMCO shafts. I have also blown a gear set.

850hp that is SC'd through any Bravo drive is going to have problems. John at the Bravo Shop is your best bet, but still the vertical shafts are only so big and can only handle so much no matter what you do to them.

John at the Bravo shop actually turned me on to George at All American Drives for Bravo parts. Seems he has some high strength alloy shafts that he Cryo's that will take 850hp.

+1 for AADS... he does the drives on my boat and I pass my customers drive to him as well... I have great respect for George... he's doing great things!!!

SCX"s

Arneson ASD#7M's. Bulletproof.

What would the cost be to change from my bravo xr's to ASD? Where would you recommend I get the work completed?

I enjoy my boat, and hate the cost and down time of the broken bravos.

+1...a bravo style drive is a bravo style drive...period. If its not vert shafts....then its gears. An SCX is the best option. You may scrub some speed with the current lower unit on the SCX...but they are working on an improved version. Or, send it to Wilson Performance and they can blueprint SCX lower to get most of your speed back.

just got off the phone with Areneson. I am looking at their Bravo Conversion.

Anyone running this? How do you like it? Hows the boats handling, and speed with the ASD?

I have heard from reliable sources that the bravo conversion Arnesons do not perform as well as the other ASD setups. Besides....they are ridiculously expensive.

I just installed the ASD7M. Still involved in "tweaking" the set up. At this point, the only thing I can tell you they do handle/respond differently than my Bravo XR's. I do believe, once I get them dialed in, I will truly like them.

I did look at the Imco's as well and these appear to be very good drives and comes highly recommended by others. SCX is a step up from the Bravo's.

So I spent all this $ on upgrading and improvements in the design and you say they are worst than the traditional Arneson.... Interesting.:bsflag:

As for cost, they are less expensive than a Bravo setup so .....

With only 850hp in a 35 fountain the is no need to drop a lot of $$$$ on something you don't need or that is way over kill.
The Bmax will work perfect on that application and you won't be with out your boat for months putting it in and spending precious summer time trying to dial it in. JMHO.

Thats 850 a side. I have a pair of 540 cubic inch blower motors, just came off the dyno.

I just dont want to replace the shafts, and have the gears blow, or something else in the bravo set up.

Other people I talk to say that the most that the braos can handle are 600 hp, and you will still need to grandmother the throtles.

But if you are actualy running the bravo conversion on your own boat, please let me know. I dont want to hear from someone who heard something.... and so on....

If you are willing to spend that much, then just go with a pair of B Max drives for less $$$.

The B Max drive is not just an upgraded Bravo. Everything is different and all the internals are bigger and stronger. Bigger gears, shafts and closer tolerances.

Mk- for what it's worth, I switched to a bmax this spring from what most would call a pretty extreme xr. My boat is a single engine 28' scarab that weighs in at about 6000 lbs running weight. I've been running over 1700 hp through the bmax since April with no signs of gear wear. Prior to the bmax, I ran through xr and Imco drives in about 2 hours each before I was left with a few salvageable parts. I would say for the money and ease of setup, the bmax is the way to go. I'd also say that at 850 hp in a light, efficient hull- you'll probably never hurt a bmax as long as you follow the bravo shops recommendations on gear oil and service intervals. The only down side of a bmax versus an xr is weight, but stronger always means either heavier or way more expensive... Just my 2 cents

Im sure John (Waconda) understands that you run 850 a side. He runs 850x3 on his 13000lb boat. I have had several sets of BMAX drives on both N/A and Blower engine set ups. Always on a Black Thunder though that weighs 13000lbs. Bmax is a Great product and Johns attention to detail, workmanship, customer relations and availability are unsurpassed.

How long of life are you getting out of the lower gears?What kind top speed are you seeing, Curious with as much hp as your running, Smitty

Dude is running 1700HP...in a 26' Scarab! (If my memory is correct)
John from the Bravo Shop sent me some pictures of LV's drive when the flex from the propeller ate away at the drive.
I don't recall a speed, but John said it accelerated like a top fuel car.

you forgot to tell him how much speed he will loose with the bmax over the bravo and how much he will loose in comparioson to the arneson even. some things are worth what they deliver. seems everyone wants to keep people drinking the bravo coolaid especially when they are selling the coolaid

Griff. Aren't the Bmax running XR lower gears?

To call the ASD#7M's overkill for 850 hp I don't get. That is what they are rated for. Even though there are plenty of people making the B1 style drives live with biggish power, is your mind at ease, when you run the boat with your fammy and friends? Mine would not be, but that's me.
Also, the increased speed from the Arnies over the rest, bears a value in itself too.

If you speak with someone about gear ratio and propping and know what you are doing when you do it you won't loose any.
Having Bmax's on my Black Thunder running 104 mph must be my down fall. :bsflag:

If you have looked inside a Bmax you would know it's not a Bravo!

Ive had the boat to 105, the last owner claimed 109 (tattle tale gps speedo).

The bravos are currently running 1.35 gear ratio.

I hear that the ASD handle differently then the bravos, in a good way or bad?

Or does it just take some getting used to?

That makes no sense to me. If you do what you suggest, but do it as a comparison between an XR and Bmax, and maximize the efficiency of both the standard XR and Bmax, the Bmax should still be slower, yes? Another thing is. If you want to increase the efficiency by surfacing B1 style drives, you are also looking at possible problems with thrown blades.

Have you thought about what your BT would run with the ASD#7M's? 108-110, maybe more? Just a thought.

When you start pushing the limit of any given engine and drive package changing the drive ratio is critical, so going from a merc XR 1.50 to a Bmax 1.32 is huge and most people under estimate that. So speaking with someone like Brett at BBlades is a very important step in the process.
I'm not talking at all about making a Bravo drive or Bmax a surface drive.
We use the back of our boat and having ASD #7 sticking out there past the swim deck 12" with trips are not for me. I think Rik has a great product for the right boat and the right person just not for me on this boat.

Waconda, What Hp is your black thunder? I love the boats but have not heard of many going over 100. Obviously Coolerman does 129.

BMAX lower gears are BRAVO XR gears. just like a imco sc, teague platnium, max machine worx, all american drive service.

Swimmng with a arneson is misleading. Swimming with ANY surface drive with larger and sharper props is all the same. Arneson, #6, M8, Indy, X power, NXT, etc. Sick of people singling out the arneson.

RE READING your question the answer is a no brainer. SCX uppers is all you need to purchase and run your sc lowers. Its one of the favorite combos on here for a compromise in strength and speed. I have personally seen a 36 apache with twin 950 hp hammer it out of the hole, jump waves, and run the boyne thunder poker run across the open water of lake michigan with not problems. He has over 400 hours, yes 400 hours on SCX drives!!!!!

The b max upper is strong but UGLY. the lower is no better then the sc you already have.

SCX uppers and your sc lowers would make the most sense, strong, easy, and cost efficiant.

Just 850's

Must be the No compromise boat? I should have put 2 and 2 together. Sweet boat just the last I heard it ran in the upper 90's. Fast no matter what though!

Trip Chief 850s. They are almost identical to my K/E engines I had in my 46. (different head mfg and cam profile)

Curious if the other mfg's you mentioned have the same build procces for the lowers as John does prior to assembly?

Like Sax says..... "Just PSI blowers" :lolhit:

John at the bravo shop might have some tricks for his lowers. Max machine worx, imco, all american drive survice, all claim they have special tricks to. These tricks still do NOT make xr gears bullet proof. XR gears are junk no matter what. NONE of this makes any difference if the MAIN POINT of the thread which is what is a economical way to upgrade his drives. Well the most economical way that gains him strength at the best price, and easiest would be a SCX upper and use his SC lower. There will be no negative side effects.

I don't know why you are bringing me into this but from my point of view you are BAGGING on my product. You claims of too much $ and sticking out the back of a boat some 12" makes you sound very wrong. Then arguing about it with members? Are you selling BMAX drives? If so, please state your position and please do not use my products as your spring board to attempt to make a BMAX look superior.

Bmax has been on the boat since April, gears have about 40 hours on them so far. Best mph so far is 133.8, Swinging a 34 pitch Maximus with a 1.30 ratio. Still have yet to really run it out as I'm still dialing in the setup with the hull.

28' scarab excel-

Datalogger shows 46 to 133.8 in 14.4 seconds, within 2280', with the throttle never exceeding 77%. So far I've spun a 34 pitch Maximus through a 1.30 ratio to 6200 rpms. The prop speed is so high that the blades spread out and forward. I started with about .700" clearance between the tip of the blade and the upper after we cut off the cav plate, and it carved almost .500" out of the upper with the tips of the blades. Working on finding a new prop to test out, something a little less prone to stretching...

I'm impressed, is your lower gear set a 17/19 then? The 15/19 1.50 gears I run used to last 10-12 hours with a little over 1000 hp and ft lbs of tq, I stretched this out to 40-60 hours or so by experimenting with different processes and settled on cryo/iso rem finishing along with premium synthetic oil (currently running the bravo shop stuff but was running Amsoil). I did switch to 1.36 lower gears that were cryoed, isoed and dlc coated this year and was eager to see how they held up but then I sheared off a billet vert shaft which destroyed everything in the lower including the case and gears so I am back to running the 1.50 gears. Im asking about your set-up because I am always curious in what works out there and what don't. I sheared off a billet prop shaft turning alot less prop too so you are doing pretty good, Smitty

Except the sc lower's still use merc xr gears which can and do fail under high tq and load, I would buy the scx lower too and turn up the power if possible to be really bullet proof, IMHO, Smitty:drink: