IPS and other drive options

[TigaWave]

Following on from the Princess 45 thread.
As we are about to launch in the UK another drive system I'm interested in some feedback from those who have or are looking at various options on drive systems.
We now have IPS, conventional shafts and more recently introduced BOSS from Seatorque. Much of the decision is left to the manufacturers who are looking for easier builds and improved performance, but the seatorque can offer both of these without the complexities of rotating drives and more complex control systems.

The joy stick manouvering on IPS equiped boats is unique but how important is this when compared to the other factors? Is it a great way to get new users into bigger boats who havn't the time to learn twin shaft manouvering techniques?

Now trying to build a pol (for the first time)
The boss system has been in the news but doesn't have the advertising power of Volvo so is not as well known.

 

[Deleted User YDKXO]

[ QUOTE ]
Is re sale value an issue

[/ QUOTE ]
[ QUOTE ]
Do you prefer simple or complex and clever


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I would hazard a guess that there's only one answer to these questions!

The BOSS system is interesting but to claim an 8% improvement in 'performance' (whatever that means?) is highly questionable IMHO for what is basically just a shaft alignment system. Have there been any comparative tests authenticated by a technical agency done to prove this claim? What exactly does 'performance' mean (speed? mpg? or what?). I'd say that if this 8% was a manufacturer's claim, then that should be clearly stated in any advertising materials including your website

 

[rickp]

[ QUOTE ]
The BOSS system is interesting but to claim an 8% improvement in 'performance' (whatever that means?) is highly questionable IMHO for what is basically just a shaft alignment system. Have there been any comparative tests authenticated by a technical agency done to prove this claim? What exactly does 'performance' mean (speed? mpg? or what?). I'd say that if this 8% was a manufacturer's claim, then that should be clearly stated in any advertising materials including your website

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Isn't the point that there is less drag from the non-rotating outer shaft? Or did I read it wrong?

Rick

 

[Deleted User YDKXO]

Maybe but to claim an 8% improvement in 'performance' is a big statement and therefore should either be backed up by an independent test or should be qualified to make it clear that this is a manufacturer's claim
Basically, as it stands, some punter could assume that fitting this system would turn his 30.0kt boat into a 32.4kt boat and, if that is so easily done, why is'nt every boat builder using the system?

 

[TigaWave]

Spot on Rick, the rotating shaft takes a surface layer with it, this arrives at the prop hub as spinning/disturbed water. Dragging a spinning cylinder through the water or air gives rise to the same forces that cause a circket ball to curve when spinning, these forces are generated by the engine, so some of your engine hp is creating this water rotation and pressure differences on either side of the shaft.

A conventional shaft also looses hp in vibration and noise, these run pretty much silent with a very rigid drive train from prop to coupling so there are only 2% mechanical losses.

Rubber bearings and unsupported shaft lengths will sacrifice hp at the prop.

They have been in use on Stolper boats for over 10 years but the builder of the system (Peter Stolper) has only recently decided to focus on supplying them to others. He sold his boat building business to concentrate on his engineering innovations.

The 8% claim is from results on their own boats, but very soon we'll have results from a builder who is trialling them back to back on a 64' sportfish with twin 2000hp mtu and 3.5" shafts.

And yes now they are available some builders are very interested.

 

[Deleted User YDKXO]

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The 8% claim is from results on their own boats

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I'm not trying to criticize you because you have a commercial interest in the system but I'm just pointing out that making a universal claim of an 8% performance gain based on testing on the manufacturer's own boats (now conveniently not manufactured any more, it seems) is disingenious IMHO and probably contravenes existing UK regulations on advertising. That's not to say that I think the system isn't any good, just that the performance claims have to be proved beyond doubt

 

[TigaWave]

Fare comment, I'll be adding more details very soon...

 

[oceanfroggie]

Everything about IPS sounds great so far and it clearly works a treat. BUT it's so new it's long term maintenance records is as of yet unknown - catch 22. Being cautious about the next new "fad" I'm happy to wait and see how it pans out, sticking to proven conventional drive systems for the mo - especially given the impact on second hand values if it doesn't turn out as "golden" as we hope.

 

[Major Catastrophe]

Wot about Yellowfin?

 

[TigaWave]

Ok and Zeus, I see yellow fin as more of a prop development, but interesting.

So as with all surveys the questions need changing! or adding to!

 

[Whitelighter]

Dammit, that was going to be my next qustion.

WHat about Yellowfin though? It looks to be perfect for single engine installs as it gives an IPS style joystick manouvering and they were claiming 30-40% fuel savings/increase in performance over a standard outdrive...

 

[Major Catastrophe]

No, I see Yellowfin as an entire new bit of thinking. Surface drive, cut through transom and 'off the shelf' diesel engine that can be easily marinised, so even an old taxi engine will drive the thing!

Jez, their website seems to be no different than last year, so I wonder if the project is losing steam.

 

[gjgm]

I wonder if this has 8pct improvement too

http://www.ybw.com/auto/newsdesk/20080429122032mbmnews.html

4 years worth of lab testing on one boat ! thats my sort of owner /forums/images/graemlins/wink.gif

 

[wakeup]

The problem with that is that given the reliability of your average volvo engine you will statistically nearly always have a problem with one of those four engines/drives/props which means frustratingly never really ever getting full performance out of the thing. I have a single Volvo Drive (new) and it took four months to diagnose and fix a serious water leak from it last season, four times the engines, four more times likely to have the same fault! Which would means an engine probelm every 3 months.

 

[gjgm]

but think of his fuel saving !
I think he has cracked the rising cost of fuel issue with some lateral thinking.

 

[nova]

As IPS users we can only say that after some initial problems with the boat, which were not the fault of Volvo but caused by the interface with Raymarine autopilot, who were absolutely brilliant in resolving the matter, we have found the system to be brilliant: quiet, fuel saving and a dream to manoeuvre even in windy weather.

 

[KINGFISHER 9]

What happened to Mercruiser's Zeus system? ... I think they were going to change its name .. not sure. ... It looked a far better bet than IPS ... Has it been launched yet?

 

[adey]

I'd don't understand the results of the last question. IPS gives more space on board, yes? Do 47% want less space in their boats? /forums/images/graemlins/confused.gif

 

[Nick_H]

It doesn't give more space on board, it gives a different layout which usually means more cabin space, but at the expense of lazarette, or on bigger boats, crew cabins.

Some people may view big cabins as unnecessary, you only sleep in them after all, and prefer lots of lazarette space for bikes, ringos, canoes, diving stuff, etc.

 

[NEB]

The Zeus system is still going but only available in very limited numbers, I think there maybe a few issues with the system so it takes a long time to produce and set up.

There was an IPS/Zeus shootout on Boattest.com using a pair of Dorals but I cannot get the website to work to provide a link!! I also heard snippets from the unofficial report by the engineers on the test and in general IPS was a fair way ahead of Zeus.