Question for Rik @ Arneson, and others.
 

Ok.

Just got back from a lunch in the marina. Nice weather on a day off. We got into a pretty heated debate about suface drives.

The question regards the ASD 6 bravo conversion. A guy at the marina has a Cobalt 302, with BIII's. Port side drive has just failed.

The topic of our debate was, if an ASD 6 would be an alternative to the BIII and Volvo drives on these twin engined sport boats, such as the Formula 310ss/br 350ss, the mentioned Cobalt and the like?

One thing everybody agreed upon was that, it is a more expensive alternative to the BIII.

What are the pro's and con's in terms of performance, efficiency and durablility on this kind of boat, with 300 hp's to 425's?

At one time I was looking at a repo Donzi 39 ZSC with 425 HP 496 HO's that was missing it's Bravo III's. I talked to Rik about doing the ASD6 conversion to eliminate the known weakness of the Bravo III's on these bigger heavier sport cruisers. All the indications I got where that it would be a great option on that boat. Of course as you mentioned at $21 - $23k per side was tough for me to swallow for that boat with stock power, and I'd think even more so on a 30ish ft 10 - 12k lb boat but if money's no object it would probably be a killer set up.............different for sure.

I ended up with a Formula 400ss instead and I have dreams of a pair of Youngs Performance style EFI 540's with ASD6 Bravo conversions but it's just a dream right now :)

I would think so too. I don't know much about the Donzi, but one of the things talked about, was that the "small boats" such as the Sun Sport Formula's and others aren't stepped bottom performance hull's, where as the 40SS and Donzi are more performance oriented in thier bottom design. One of the big topics in our debate or rather argument, was wether or not the time to plane and midrange would suffer a great deal. If you could still get the 4-5 sec. time to plane, and a good midrange efficiency, that you kind of need on a boat like that, combined with the great durability, and possibly better top end of the Arnesons, that would be a dream setup for shure. And don't forget the rooster!:coolcowboy:

The drives working are not an issue. The drives holding up reliably to the power is also not an issue. The issue of cost vs the cost is an initial up front issue that can have a payback depending upon the maintenance schedule of the BIII's. The more they break the faster the payback.

One thing I am very certain about is the increase in speed as all the BIII's we replaced have increase speed significantly.

The same boat with Arnesons will handle better, around the docks as well as slow speed and rough water conditions. The acceleration will also improve with the Arnesons. Con's if it can be said would be up front propeller cost but at the same time purchasing four propellers for a twin BIII setup is not cheap in the slightest, especially when only Merc (or even Volvo) makes those propellers.

Mid range cruise speeds will rise along with top end with the Arnesons over the BIII's or Volvo Duo's

Sounds pretty interesting Rik.

If you take my buddy's Cobalt 302 as an example. It runs about 51-52+ with the 6.2's. Not shure about prop's, but my guess is 26"
Do you have an idea about top end improvement? What about time to plane? And the big question. Are they more corrosion resistant than the BIII's?

I will take this info to the marina this weekend. A new custumer could be in the near future. There are quite a few boats where I am with BIII issues - corrosion, drive failure, ect.

Thank you Rik

You won't have corrosion issues with the Arnesons, especially if the boat is bonded correctly. Getting on plane will not be a problem as on those heavy boats we can run more diameter than the BIII's and more blades which will help getting out of the hole.

Speed, midrange will close to 10 mph and top end 5-10+ depending upon the boat.

WOW! Would those number also apply to my Formula 400SS? Seems too good to be true although I guess if I'm spending $40-$45k on any upgrade I'd want to see some big time improvments :) Right now I have a pair of 415 HP 502 Mag MPI's............I normally cruise at 3200 - 3400 RPM and that = 32 - 34 MPH with a top speed of 50 - 52 MPH at just over 5k RPM. So are you saying that all things being equal with the same engines if I did the ASD 6 Bravo conversion I could expect to cruise at 42 - 44 MPH at 3200 - 3400 RPM, have a top speed of 57 - 62 MPH, have better around the dock handling, get up on plane as fast or faster than I do now, have better corrosion protection, and drives that will live forever behind this power or even substantially more even in an 18k lb boat? And I guess if you factor in what you could get for the Bravo III's and related "take off" parts in resale if you did the swap before you ruined them it starts to look like a more interesting idea.

What type of regular maintenance is required for the Arneson's? Any hidden costs like a $3k flux capacitor that has to be replaced every two years as a "regular maintenance" item? :)

I wonder what a pair of take off Bravo III's and related parts are worth anyway?

Thanks, Pat

In not so many words, yes. Every boat is different but the mid range has consistantly been about 10 mph faster than the Bravo's and this is 80% of your boating time so this is why I stress this to people.

No flux capacitors though. Just change the oil seasonally, monitor the zinc anodes, and run the crap out of it.

Don't forget, the cost of the Arneson includes hydraulic steering!
Definitely a nice upgrade.

Jeff

That's cool. While under way I'm pretty much either in a 5 MPH zone or cruising at 32-3400 RPM. Anything over that for extended time and it uses some serious fuel. Coming from a 70 MPH boat that cruised at 50 this boat can get boring..........feels like it takes FOREVER to get to the destination sometimes. It would be nice to be able to cruise in the mid 40's with similar economy to what I have now.

Another question............are there any modifications required when installing the conversion that would make it difficult to put the Bravo III's back on later? The thinking is if I did the conversion and kept the Bravo stuff, then decided to sell the boat later, could I easily reinstall the Bravo parts so I could keep the Arnesons for the next boat?

Thanks again, Pat