Need advise!!
 

I have a 94' 271 Sr1 with the 502mpi 415hp/B1 1:50 that is in the works of new power. I have a 598 NA 800hp/798 ft lb tq that is getting ready to go in.

-What kind of speed should I expect out of the boat?
-Do shorties make a difference on these boats?
-I know I need hydro steering, but dual or single ram?
-Do you think the B1 drive is going to last any amount of time?
-Will the stock engine mounts handle this kind of power or should I use a offshore mount?
-Should I add bigger tabs to help easy pressure on the drive?

Any thing else I should know about!!lol
The boat will run 64-65 on gps now, I am hoping to be in the 80's.

All advice is welcome as I am in Afghanistan and I dont get much time at home. With that said, I want all the right parts sitting in my shop waiting on me to be installed to make this setup work.

Thanks,
Brad

Brad: My 2 cents on a few of the items. I think you should look at shorties, had a 357 and raised the x dimension with good results. Also, look into a stand-off box. dual rams are a must, I understand a single ram will just twist the drive. offshore mounts are a must. increased speeds & torque will result in more forces on the stock motor mounts. You should definitely run in the 80's. finally, you will probably toast a lot of bravo drives What about a arneson surface drive? There is a 382 in cali that runs over 100 with surface drives!!!! Good luck with the project, post some pics as you proceed.

What Intake ?
 

Is It Stock ? Did That To Mine And It Just Did Not Get Enough Air Went To A 525 intake on a 540ci and a 1" imco upper & lower and a Lab 30p and now run mid 80s with just hydo assist but also a blue printed bottom it now runns on a Rail no issues at all . 647hp 680tq @ 5200 ,83gps with 4 people with full fuel . Good Luck with your Build Up!

[QUOTE=tony manzella;3349695]Is It Stock ? Did That To Mine And It Just Did Not Get Enough Air Went To A 525 intake on a 540ci and a 1" imco upper & lower and a Lab 30p and now run mid 80s with just hydo assist but also a blue printed bottom it now runns on a Rail no issues at all . 647hp 680tq @ 5200 ,83gps with 4 people with full fuel Also Toss The Tin Foil Bennets I have Dana's . Good Luck with your Build Up! :evilb:

Thanks for the input, I really need it at this point!! I have looked at the surface drives, but they are out of my price range. I have the offshore mounts already, just did not know if they were a must, so I will use them.

Keep the advise coming!!
Brad

The boat is stock now(motor is out). The engine did not get enough air in your boat? I hope that does not become a problem with this one as I dont want a scoop cut in. My boat has pretty large air inlets on both sides, so I hope that is not a problem. I am really thinking of selling this 598 and dropping back to a mild 540ci mainly due to drive issues. My biggest concern is finding a drive that can handle this type of power without having to fix it every other weekend!!! Thanks for the input, please advise if you think of anything else.

Brad

Come on guys!!! All of the knowledge and experience about high power and Formula's on this forum and no replies!!lol I know someone can advise or has a opinion.:evilb:

Thanks for the input so far, it was helpful. Please keep it coming.

Brad

It will be REAL had to get a Bravo to last with that kind of power. Even an imco or .... will not last real good with that kidn of power and the weight of your boat. Konrad Ace would do it and also give you a stand off box at the same time. Still not a cheap option but it is rated for 800hp and 800ft pounds of torque.

Have you heard much about the "new" BMax drives? There are so many people running big power, you would thing more options would be out there.

I could change the cam and de-tune the engine back to around 675-700hp.

I thought the Konrad was a TRS replacement, it will work on a bravo boat?

Brad

I had a 800hp motor in the boat "93 271" Old school Bravo is fine but get it up to 50+ MPH before hammering on it, Mine lasted 3 years. I ran single ram Hyd steering but, That's all the money I had at the time. I went with IMCo with the Duel wing plate so I can upgrade later. Def. in the 80's. I'll be exp. with a shorty this spring, Keep us posted and Good luck!

The Bravo is going to be your weak link as you already know, but there are a lot of things that can be done to help reliability. High HP and a single is even tougher on the drive then high HP and twins, but you wouldnt be the first to do it. I was on a few Bravo threads with a guy who has over 1000hp in a single 272 Baja. The biggest issue he has is tearing up lower gear sets. I'm running 750/800hp through mine with good results, but I'm very diligent with maintenance.

A dual ram full hydraulic steering, 280 K-planes, HP transom assembly, Bravo XR, and offshore mount(nothing lag bolted, all thru bolted) would all seem mandatory. The K-planes, while not mandatory to dial in the boat, will sure help when the weather turns bad. An extension box couldnt hurt, and if in the budget, should add stability to the combo.

A couple simple upgrades to the Bravo XR to help it last with high HP would be a billet top cap, hard shimmed pinion, upgraded clutch shaft, upgraded vertical shaft, hard shimmed lower prop shaft, and a good drive shower. I'm also running IMCO extension boxes with there torsional input shafts, which help absorb and cushion high torque loads.

Good luck

LE

What motor are you running now? What was your top speed, what prop did you use? I will go with the dual ram set up for the steering. Let us know the results of the shorty.

Brad

So the Baja and you are running B1's or Xr's? Does someone sell a Xr built as you described above?

Part of me says try the B1 and see what happens, the other part tells me dont risk that drive coming apart and hurting my wife and daughter when the boat goes out of control. Can the boat sink when the drive lets go?

Thanks for your help!
Brad

Brad

Konrad ACE is for Bravo replacemt.

I am hoping to make a deal with the guy in the swap shop for one of those drives he has!! I will try to find the ACE package you are referring to and compare the prices he is asking to what just buying it all new would cost.

I am talking to a guy local to me that has a Cobra race boat for sale. He has a 867hp blower motor running it through a IMCO ext box, Bravo upper and Sportmaster lower with dual ram steering. I am trying to trade him my built vette and a new 4 wheeler I dont use. I will take his power out, put my stock 502mpi and b1 on his boat and sell it to get my money back. I would then get all the components I need pretty much for free and end up with a 10hr blower motor for sale as well. Heck, I might make some money to put toward my boat!!

Thanks for the help guys.
Brad

What is the price for a new Konrad ACE set up?
Brad

Contact a member by the name of "Biggus" on the board. He can tell you if you would be able to buy just the ACE box and tranny or if you would need to go with the entire set up and also give you pricing.

Not sure what the Baja guy has done to his. Mine are 2003 Bravo XR uppers, IMCO 1" shorty's with upgraded shafts and Merc gears. All the upgrades I mentioned I did myself with help and advise from MaxMachine Worx, out of Lake Havasu.

As far as drive failure and sinking goes. you would have to rip the drive off the boat by the gimbal ring and bellhousing, which would let water run in thru the u-joint bellows. Not likely to happen unless you hit something really big, or maybe run the boat in 6 footers at 80mph while try to turn(seen a race boat break a gimbal ring on some you tube video). Either can happen on most any drive system.

Most Bravo failures due to over powering will by shafts or gear failures.

I talked to the Conrad guys at the Miami boat show this year. Currently all there drive setups use an external transmission(borg warner 72c series). So the setup you are talking about needs to have the Conrad Bravo conversion with the trans in a extension box(that lets you keep the engine in its current location). If not you need to remount the engine 12" foward of its current mount to make room for the transmission. Dont know if your bilge will allow that?

The HP transom assembly offers a slightly stronger gimbal ring and bellhousing(added security), but you can bolt any B1 or XR to your std transom assembly (you might have to change the gimbal bearing to the later style, $100). A dual ram hyd steering setup is whats going to keep the boat safest.

LE

Will do, I think if I go Konrad, I will just buy the complete set up from him instead of mix matching and needing to keep buy parts to make the 540's work with the ACE.

I will PM biggus for price.

thanks guys
Brad

The good thing about the Konrad ACE is it comes with dual ram steering. Thanks for all your help, hopfully I will have one bad a$$ boat ready for the summer running in the mid 80's worry free!!

If I can ever get out of Afghanistan!!

Brad

I just got off the phone with Biggus (Kurt). He is on the road and with out internet. He should be back home I think he said Friday and will get back to you as soon as he does.

Jon

Thanks Jon, do you have a rough est. on what these drives are costing? I really like the built in steering on the Konrad set up.

Brad

Custom 496ci N/A little less than 600hp 24p bravo one but I just got a 25p Mirage that I been wanting to try for a long time it's going to be in the upper 70's in NC this weekend so I let you know what speed now is. My blower motor was about 82MPH. How about you what prop are you running? and speed?

I live in Elizabeth City NC, not to far from you.

With the 502mpi and a 21p bravo one, I was get 65gps with next to no fuel, 2 people, and a foot of chop. I wanted to try a 23p b1 but never did. I think once this 598 project is finished, I will start with a 28p 4 blade and see what happens.

Why did you get rid of the blower motor?

Brad

Brad,
I assume you are in the military. If correct, thanks for what you are and what you are doing to allow all of us to be here in the USA and enjoy our freedom to live and boat as we please. Good luck on your project. Hurry home safe! Dan

I am a DOD contractor for the US military. I work/support the US military on a daily bases. Thank you for your comment, I hope to be home safely soon!! It is a different world here and it really works on you over time.

Brad

Frist the motor went lean "burned #6 and #8 piston" and someone wanted the Blower and the whole assemble and they made me a offer I could not refuse. At the same time my buddy had a new 454 block and and brand new 496 stroker kit Complete that he Needed to sell bad. 1800 bucks for everything, so in a nut shell I'm back to N/A but I have a 515ci Block in the garage ready to go Block, pistons, rings ready for a Blower. I just started up a Overhead Crane Service company in December and Money is just to tight right now. I quit my job the first week in Dec. But if things keep going like this I should have toy money by dec. this year. :coolcowboy:

That's the same prop I went with, it handled great. It's a Great place to start.

The 23p or the 28p? I am looking at the 28p in the swap shop now. Requested pics, if it looks ok, I will buy it and see where that puts me.

Brad

28p

Cool, I will buy it and see what happens. Thanks for your input.

Brad

I would not go with a Konrad. If I was going to get a new drive for 800hp I woudl get an Imco SCX upper and SC lower. This will bolt right up to your current transom assembly with a helmet change and will be bulletproof (the upper will anyway). Not to mention no transmission, no need to recut the transom, just put on your new helmet, bolt on and go.The lower will be a little weaker than the upper, but those gears are less likely to fail.

There are guys running 1000hp through their SCX uppers with no failures to date that I have heard of.

Thanks, the SCX/SC combo is still a option. I got a price for the Konrad and had to break the Defibullator out:lolhit:
The Konrad is not out of the picture, but not first on the list either.

Brad

Brad, unless you got a ton of $$$$ get the New Outdrive of your liking. Run the Bravo one it's the old school one and it will handle your power just fine. get it gone through spend the 400 bucks on that and keep the 5-10k for the outdrive and buy the 1500 used bravo one and put it on the shelf. IMHO
Brad the money I have in the old girl I'll never see again If you think you need that bad to the bone outdrive go for it I'm just saying if you ever wanted to upgrade boats you might " Might" see 50% R.O.I. and Custom engines do not sell in used boats. I'm not trying to be a D**k but I'm in the same boat your in and I had mine for 5 years and If I was to do it over again I would of went with a Blue Motor " 525 or 600 Sci " They sell. Fact. I had been looking at upgrading boats and it's just not worth it now I got to run it for a while unless I want to take a Huge HIT. I looked a 2003 271 for the " color scheme, white dash, faster hull " Not that your trying to sell your boat but, you might in the Future. I hope this helps but this boats require a lot of power to break 80mph but if your easy on the throttle to about 50mph and your not going to be running at W.O. for 25- 50 miles save the cash.

Thank you for the very honest reply...I think you might be a mind reader tho!! I am looking at 353's and 312's right now. I can buy the keys a hell of a lot cheaper than build this one. People are unloading these style boats for cheap with the upgrades already done. The 271 rides great, but I have always wanted a 35'-38' powerboat and your right, I will NEVER get half of what I will have in this boat out of it. Thanks for the input brother.

Brad

No Problem! Live vicarisy through my mistakes... Don't get me wrong I love my boat and it does ride Great! +1 on the reply :evilb:

Let me guess, you thought the Arneson was expensive :eek:

Rik, I did not price one out.
Brad

Might be maken some head way!!:evilb:

A guy has Bmax's for sale in swap shop, a guy has steering for sale in swap shop(single ram tho), I bought a few props. All I will need is the HP gimbal and stike a deal with the above to be in business:drink:

Lets see what happens, seal the deals and let the build begin...Once again, if I ever get out of this sand pit!! Ticket for friday if nothing changes:coolcowboy:

Thanks for all the help and advise along the way guys.

Brad