I am thinking of changing to the ASD6 "Bravo Conversion Kit" from my current Bravo 3 set up.

I am running (only!!!) 2x 300hp Yanmar diesel 6LP engines on a Sunseeker Superhawk 37 and get about 42knots.

The B3 drives have been rumoured to fail on the 300hp Yanmar and I have already had an upper gear set replaced.

The big plan is to upgrade the 300hp Yanmars when they break to something bigger, maybe the new 480hp Mercruiser diesel or 440/480hp Yanmars.

Obviously money/mortgage/Mrs means this doesn't all happen at once (and legs need to change before engines)...so if I go Arneson:

(i) Do they ever break? Obviously 300hp diesels won't test the drive....but what about 480hp diesels with diesel torque being that much higher than gas engines? The ASD6 is going to have to be a long term investment with no costs other than maintenance to be worth paying for them and then going up to the next engine choice. Otherwise 480hp Mercruiser and NXT drive package is the right answer.

(ii) Will the ASD6 "grow" with me? Can I fit them on the 300hp Yanmars and with minimal cost fit them to the "next" engine - whatever that might be?


Any idea what sort of performance increase I can expect moving up from B3 to ASD6? I have read elsewhere on Offshoreonly.com about a 5mph which seems like nothing compared to the different underwater profile the ASD6 has compared to a sterndrive....



Disp 12,800lbs
Draft drives down 3'1
Draft drives up 2'2
LOA 37'2
LWL 28'5
Beam 10'2

I built a set of my 925 efi's (actually 970 hp, 1075 ft lbs tq) for a 388 Slingshot Hustler with ASD 6's. The rig has 270 hrs so far and has not had any problems with any of it. I'm not sure what tranny they typically come with, but this one has Bam Super Cyborgs. The only thing I have done to the drives is to upgrade them to ASD 7's, which entails changing the tube to one with a larger skeg. I just removed the drive tube, removed the prop shaft and installed it in the 7's tube. The skeg is much larger which worked great at settling down this boat at over 100 mph. Other than that, they have had regular oil changes and one boot change. They are now 5 1/2 years old and have performed flawlessly. I'm not sure about your setup. That is a heavy boat and may require the 8's. Give Rik a call. He is also on OSO as Rik. He will set you up with what you need. He is a great guy that is very knowledgable. I don't think you will be dissapointed. Hope this helps.
Eddie

Cool, many thanks....Rik has just contacted me also as I emailed Arneson direct for some other info.

The Mercruiser Quantum Engine Series QSB5.9-480 develops 940ft-lb and the Yanmar about the same...so they're within the same ballpark as you.

Any other opinions out there?

the only thing would concern me it the maneuverability of the asd vs the bravo..their not good in the harbor..

I tell you what.....I would put that Hustler against anything around the dock. It is up there with the best docking boat I have ever driven. It is amazing how well it docks. I can tell that you haven't driven a boat with Arneson's, because if you would have, you wouldn't say that. I was really impressed. You can make it do whatever you want. I don't know if it is because the props are so far back or what. What I do know is that there is absolutely nothing wrong with the way it docks. I'm not being an a..hole Mr. fixxall, I am just relaying my experience. The owner of the Hustler also drove another boat with Asd6's before he bought the Hustler and it was the same way. There seems to be a myth running around that they do not dock well. I'm not sure where it came from, but it could not be farther from the truth.
Sorry if it sounds condesending...it was never meant to be. It's just the facts as far as a 38' performance boat. A large cruiser may be different, but they do use quite a few on larger yachts. So, I would think they would do just as good.
Eddie

.....yeah....I have heard that about surface drives generally.

Way I see it I spend 5 minutes maneuvering in the marina compared to maybe 5 hours bouncing around at 40knots...so am trying (hard!!!) to justify it that way...

Let's see how much new GRP I need for bumps and scratches....hopefully the increased fun on the water makes me forget about the dock...

They work fine in the harbor. The closer to the center line you mount them the worse it will be. This it true with all outdrives!

Jeff

In a 50' magnum with 540's it wasn't the best docking boat Ive driven, it sucked!

just my 02!

Never driven a boat with arsons but it is all physics... the farther back the props are the less leverage you will have(turning) the closer the props to the boat(cruisers are under the boat} the more leverage you will have. I'm not stating that a boat with arsons will not dock great or manuver around the harbor fine. its just how it is. yes,also the distance apart from drive to drive will make a diff also. I say go for it, reliability and performance, how can you go wronge?????

I may be wrong but would an ASD/6 be up to the job,with the 300 yanmar yes,but the 6ly yanmar or cummins are a different animal altogether,was always under the impression these high torque motors needed the asd 8 exception being if theres an overdrive ratio transmission of .75/1 or similar to limit the torque,would be interesting to hear any thoughts on this as well.