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Old 06 May 2008, 17:41   #21
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Country: UK - N Ireland
Town: Cushendall
Boat name: JanJack /
Make: RedbayBoats / Brig
Length: 8m +
Engine: Yanmar 300 / etec 50
Join Date: Mar 2008
Posts: 81
Thanks Andy, It's always good to hear firsthand experience.

Polwart;
Although I feel it is a compromise it is one I probably will have to make. You would be surprised how little redbays there are and as current owners of a redbay and living in the village were they are produced and regularly using and seeing them being made we are very fussy about our requirements and it is hard to get a perfect one second hand.
It is also a good price considering the amount of boat you get. Provided everything starts and works during the test drive and it does a reasonable speed - 32 knots I think we will take it, and I might fit trib tabs to it anyway to increase comfort in head on seas and maybe get 2 or 3 knots more out of it on the flat as a bonus.

I'm certainly going to look into chipping it. I have sent steyr an email but who else should I contact or can anyone give me a link? Is it something I could do or would someone specialized have to do it? What sort of negative effects was codprawn talking about at highspeed and how long would you have to run it at those rpms to do the damage?
At about 3000 rpm is there any damage you could do to chipped engines?

Almost running out of questions now XD
Thanks again

Conor
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Old 06 May 2008, 18:44   #22
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Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
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Originally Posted by chorscroft View Post
I'm certainly going to look into chipping it. ....What sort of negative effects was codprawn talking about at high speed and how long would you have to run it at those rpms to do the damage?
Conor, to gain more performance this way the engines need to have some form of electronic diesel control and your pictures show the engines with cable control so the fuel system may be manual. However, there are 3 ways of doing it depending on the type of diesel injection system on the engine. They all rely on providing the engine with more diesel fuel and this works because diesel engines are normally run on an excess of air.

Firstly, on a common rail diesel it's possible to do it simply and for a few pennies by fitting a resistor into the fuel pressure sensor circuit. This fools the electronics into thinking the fuel pressure is a bit low so it increases the fuel rail pressure. The result is increased fuel injection pressure and therefore more fuel will be injected during the time the injectors are open.

Second, the chip route works by remapping the amount of fuel which the engine receives by rewriting the control program within the engine management system.

Third, and sometimes also known as chipping, is an add-on electronic device which intercepts the signals between the engine's electronic control unit (ECU) and the electronic control section of the diesel pump and it tricks the pump into delivering more fuel than the ECU has demanded.

Now, you can make use of the extra power in two ways. I'm going to presume your boat and engine are correctly set up at the moment.

Firstly, you can choose not to do anything about the boat set-up. The extra power will be available for improved load carrying, easier planing and generally better performance and throttle response. Also, this route is unlikely to stress the engine unduly because your extra power use is likely to be transient in nature and cruising will still require only the same power as the original set up. However, the engine will over-rev when at wide open throttle (wot) and you will need to take care not to do this.

The second option is to re-prop the engine until wot produces the correct maximum engine revs. This will give you the extra speed you are looking for but at the expense of extra stress on the engine. Also, the engine will be more stressed during cruising because you have over pitched your propellers in comparison to the original set-up and this will require you to open the throttle more to achieve the necessary power because the engine will be running more slowly at a given boat speed. This will probably put you outwith the manufacturer's duty rating for the engine. Do a Ribnet search for info regarding engine duty rating.

I hope this clarifies things a wee bit for you.

Edit: I forgot to say; trim tabs will be a good idea. They are unlikely to improve your top speed but they will give you an extra control option in a head sea and they can be used to control listing, which you will definitely have in a side wind.
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Old 06 May 2008, 18:45   #23
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Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
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I suspect Steyr will tell you to get stuffed - the trick is to find what car application the engine is used for as there will be a chip for that.

You could try

http://www.mermaid-marine.co.uk/

They sell Steyr engines.

http://www.solware.co.uk/car-perform...-booster.shtml

Try asking these as well.

Don't listen to the crap it will blow your engine up etc - think of the extra revs as for short fun blasts only - no more than 40 mins say of full throttle at a time. Many car and van engines are available in say 3 different power ratings but the engine is the same.

For example a big V12 MAN diesel may be rated at 2,000hp on a Sunseeker - on a trawler the same engine will only put out say 1,200hp as it will have a much harder life - all that's different is the rev range!!!

Just read Jwalker's post - spot on!!!
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Old 06 May 2008, 19:03   #24
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Country: UK - Scotland
Make: HumberOceanOffshore
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Quote:
Originally Posted by codprawn View Post
Many car and van engines are available in say 3 different power ratings but the engine is the same.

For example a big V12 MAN diesel may be rated at 2,000hp on a Sunseeker - on a trawler the same engine will only put out say 1,200hp as it will have a much harder life - all that's different is the rev range!!!
Not necessarily. The Sunseeker engine will have a lesser duty rating.
Quote:
Don't listen to the crap it will blow your engine up etc - think of the extra revs as for short fun blasts only - no more than 40 mins say of full throttle at a time.
You may find that is close to the standard leisure duty rating for the engine before any modification!

Are you going to underwrite that advise, Codders?
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Old 06 May 2008, 19:16   #25
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Country: UK - Wales
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Originally Posted by jwalker View Post
Not necessarily. The Sunseeker engine will have lesser duty rating.
You may find that is close to the standard leisure duty rating for the engine before any modification!
Are you going to underwrite that advise, Codders?
That's what I meant!!!!!!!!!!!!!!!

As to the Steyr there are 2 power ratings 144 and 163hp - the 163 revs 200rpm higher and is marked for private use only - the 144 is marked private/commercial.
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Old 07 May 2008, 03:13   #26
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Country: UK - N Ireland
Town: Cushendall
Boat name: JanJack /
Make: RedbayBoats / Brig
Length: 8m +
Engine: Yanmar 300 / etec 50
Join Date: Mar 2008
Posts: 81
I'm guessing since the engines are 1998 they are most likely to use the resistor system? Can anyone with a mechanical mind do this one? What are the increases likely to be going from 2 x 14 to 2 x 163? 4-5 knots?
If I repropped the engine to increase my cruising speed what kind of damage could I be doing? It currently burns about 7 gallons an hour cruising - will this increase much?
Say I run it for 200 hours in a year and 20 hours of those are at WOT - Does this have a significant impact on engine life and when to the changes become apparent?

Regards

Conor
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Old 07 May 2008, 04:42   #27
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Can anyone with a mechanical mind do this one? What are the increases likely to be going from 2 x 14 to 2 x 163? 4-5 knots?
About 1.5kn. Probably not worth the effort.

Conor, you're grasping at straws. You're not going to make that rig into a fast boat. If you love the boat, buy it. If you find yourself constantly frustrated by its lack of performance, consider re-powering it. Factor that into your buying decision.

I've never driven a Redbay so the following comment is purely an observation.
Given the remark from the builder about the boat being a cut down 9.1mt, that the twin engines are short and therefore this puts their centre of gravity a little rearward and presently both drives are using fins to give stern lift. But, the boat has a substantial cabin and plenty of fibreglass structure at the bow which could be considered to balance the stern, then I would want a good sea trial to ensure the boat handled well especially its ability to transition onto the plane in rough conditions. If this is lacking, you may find yourself at only displacement speed in a rough head sea and that will make nonsense of your quest for top speed.

Your other questions may not be answerable without a crystal ball and I don't have one. Codders might have one, though.
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Old 07 May 2008, 05:01   #28
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Country: UK - England
Town: Over here
Boat name: S.S. Nobstick
Make: Three Wise Monkeys
Length: 3m +
Engine: 44lbs of thrust....
Join Date: Nov 2003
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Quote:
Originally Posted by chorscroft View Post
..... think it would only do speeds in the low 30 knots e.g. 32, 33.


Quote:
Originally Posted by codprawn View Post
I would say you might get a bit more in an ideal setup - maybe 35 - 40 mph!


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Old 07 May 2008, 09:08   #29
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Country: UK - Wales
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Boat name: Too Blue
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Engine: Suzuki DT225
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Quote:
Originally Posted by jwalker View Post
About 1.5kn. Probably not worth the effort.

Conor, you're grasping at straws. You're not going to make that rig into a fast boat. If you love the boat, buy it. If you find yourself constantly frustrated by its lack of performance, consider re-powering it. Factor that into your buying decision.

I've never driven a Redbay so the following comment is purely an observation.
Given the remark from the builder about the boat being a cut down 9.1mt, that the twin engines are short and therefore this puts their centre of gravity a little rearward and presently both drives are using fins to give stern lift. But, the boat has a substantial cabin and plenty of fibreglass structure at the bow which could be considered to balance the stern, then I would want a good sea trial to ensure the boat handled well especially its ability to transition onto the plane in rough conditions. If this is lacking, you may find yourself at only displacement speed in a rough head sea and that will make nonsense of your quest for top speed.

Your other questions may not be answerable without a crystal ball and I don't have one. Codders might have one, though.
I didn't notice that doelfins or similar were fitted - in that case trim tabs prob won't help much - the boat must have been pretty stern heavy.
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Old 07 May 2008, 10:57   #30
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Country: UK - N Ireland
Town: Cushendall
Boat name: JanJack /
Make: RedbayBoats / Brig
Length: 8m +
Engine: Yanmar 300 / etec 50
Join Date: Mar 2008
Posts: 81
What sort of money are you looking at to repower it with say something around the 200 hp mark? Would the old legs fit new engines? Any idea what money you'd get for the steyr? I would hope it would be decent considering there is less than 200 hours on them. With 2 engines around the 200hp mark you would do over 40 knots wouldn't you? I know redbay made a 9.1m with 2 240hps and it did over 50 knots on a heavier boat.

Regards

Conor
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