Upgrade options and performance/£££

[Athito]

Am thinking of some upgrades / changes to the boat for 2010...but am struggling getting realistic (or any) ideas of the performance change I will see.

My current top end is around 43 knots.

I have already sealed off all unused hull fittings and reduced weight (though I am obviously not going to get down to some of the displacements I see on other boats here !!!). I can lose maybe another few hundred kilos here and there.

The only upgrade that seems to make sense at the moment is Lab finish & cup props at £60 a blade from Steel Developments....12 blades £720 (ex VAT)....though Steel Developments won't be drawn on what sort of performance gain I might see, they'll only commit to "...this should give you an increase in top speed..."

Any ideas????


Other (more exotic) ideas include

surface drives (though Arneson also won't suggest a performance target...and finding ASD8 in the UK or even US second hand is a struggle) and/or

re-engining ....though I won't do this until my Yanmars die. I will then go for 440hp Yanmars or 480hp Mercruisers with either surface drives or NXT drives if I go Mercruiser....though both these options are years away though and I want to squeeze what I can from some tactical changes to the current set up....



Boat is a Sunseeker Superhawk
Beam 3.11m
Disp 6,000kg reasonably loaded, no crew
Draft legs down 1.15m
Draft legs up 0.65m
Fuel 700litres
LOA 11.34m
LWL 8.65m
2x Yanmar 6LPA-STZP 300hp on Bravo3 drives Ratio 1.65:1 and standard Mercruiser 26" props.

[Renegade]

Dave does my props and i do trust him as i have had results from his work but props are a dark art and it is something you have to try(obviously £750 is a lot totake a chance with).. but no one can committ what results you will get from prop work. and depends how much performance you want to gain
good luck
Paul

[Cookee]

I think the problem is you are chasing an impossible dream - it is always possible to make small increases here and there, which could be the difference between winning and losing a race, but to spend any decent money on what is quite a heavy leisure boat for such small increases in speed is probably not worth it.

I think the best option would be to repower with surface drives and increase the HP significantly as well as throw everything out that you really don't need, but depending on how fast you want to go and what you want to do with the boat starting from scratch maybe the best alternative as new engines and drives would cost way more than the boat would be worth in the end.

New or new to you faster boat!

[TobyC]

goldfish d max upgrade for motors to 380hp !

[scarab racing]

Have you thought about having the injection pump tweaked for more preasure/fuel as this would have the same effect as a preformance chip would on a new car.

I have had the pumps uprated on a few older type cars and range rovers before the electronic injection took over and had great results, a lot smoother and a lot more pull / acceleration

I run the same engine and drive and i'm thinking of doing this, shouldn't be much money for hopefully good gains.
(maybe not massive gains but £ to mph must be worth a look?)

[JOSH]

Its not worth playing with the pump as 6 lps are on limits as it it and over 4000 rpm loaded thay have valve bounce and you will push your ex temps up. which will end up to early engine wear or even worse.

if you did do this then you would have to have pyros monitoring your ex temp on dash or well i would.

Just my 2 cents


JOSH

[scarab racing]

I agree with you Josh on the earlie engine wear but then any preformance add on's will lesson engine life.

How do goldfish up the power of the engine to I think 350 bhp or is it 380?.

unless they do major internal work they must still be looking at pump or turbo as these are the two main options in more power.

Speaking to a couple of guys who have the same engine they are reving to 4500 rpm and don't seem to be having any trouble.

I think you might have valve bounce and other related problems in a smaller boat that is air bourne a lot but the size and weight of boat that we are talking i dont think it would be a major problem.

I do agree its your opinion and I respect that but if no body pushed the boundreys or tryed different things we would all be driving the same boats at the same speed.

Good luck with what ever you try and keep us posted as I will probably do the same if you get good results.

[Athito]

Originally Posted by Cookee

it is always possible to make small increases here and there,

Yep...and I am wondering what small increases here and there I can make to get a couple of knots from props; a couple from another tweak; a couple from another - ultimately (maybe) to get me into the "flat out 50 knot" bracket....to give me a cruising speed well in the 40's.

Originally Posted by Cookee

I think the best option would be to repower with surface drives and increase the HP significantly

Agreed....but this is a significant investment...and not one I am looking to make this year. I would need a "big" reason to invest that sort of cash in the boat....like knackering my Yanmars!!

Originally Posted by Cookee

throw everything out that you really don't need,

Agreed....but to get the Mrs anywhere near it I need to retain a "leisure" element on board....to make a significant dent in 6,000kg sounds like stripping out the berth, galley and - most importantly the telly! Not an option!!!

If I was going down that route I would but an old Cigarette hull from the US, or a Cat, for $15k and repower that...and just use it as a pure toy...then I have two boats...not a great place to be as I only get out on her every other weekend anyway.

Originally Posted by Cookee

New (or new to you) faster boat!

YEP!!!! But that one definitely won't get signed off at home....yet!

[Athito]

Originally Posted by TobyC

goldfish d max upgrade for motors to 380hp !

The UK Goldfish agent is on this forum...I spoke to him a few months back when I had a turbo problem to see if he:

(1) had old/recon turbos he could sell me cheap

(2) could go the other way and sell me upgraded turbo/fuel/etc as a bolt-on so at least I could get more zoom if I had to replace my existing turbos

Goldfish (it appears) do a helluva lot of work to up the HP on these engines....it isn't just swapping out a few components....unfortunately...otherwise I would likely hav gone that route.

[Athito]

Originally Posted by JOSH

Its not worth playing with the pump as 6 lps are on limits as it it and over 4000 rpm loaded thay have valve bounce and you will push your ex temps up. which will end up to early engine wear or even worse.

All agreed....and (another!!) expensive repair job I can do without!

I am looking for ideas to tweak within known boundaries (I don't want to be an expensive guinea pig!!), with bolt-on / aftermarket accessories or components that weren't around 10+ years ago when my Yanmars were installed...

[Cookee]

Another thing to consider is whether the hull will do 50knots without massive power - pretty much all hulls have a natural limit on their speed, and you may be close to that already, my first stop before you spend any money would be the factory, they will have records of different setups and power to weight calculations which will tell you if 50knots is even achievable with what you are starting with.

[Athito]

Originally Posted by Cookee

Another thing to consider is whether the hull will do 50knots without massive power - pretty much all hulls have a natural limit on their speed, and you may be close to that already, my first stop before you spend any money would be the factory, they will have records of different setups and power to weight calculations which will tell you if 50knots is even achievable with what you are starting with.

now that IS good advice...the hull is "good for it" as Sunseeker powered the boats with twin petrols for US export (top of my head I cannot recall top end but think it might have been 60 knots)...but to see a curve for X weight Y power gives Z performance and then have a feel for what I need to aim for is a great idea...

[cfun]

Going on the (if) the boat was made for the extra speed bit, if I recall the 34xps that raced in the early 80's bust up it's hull at the start of the RB 84 or so I was told and that probably did early 50ishmph and a friend re-powered his early 80's single engine Sunsqueeker with a much higher hp diesel unit in the late 80's and promptly bust the hull open too

Does your boat have a wider beam than the old 34XPS and if so that would of probably been more suited to some Xtra oomph

[Athito]

Originally Posted by cfun

Does your boat have a wider beam than the old 34XPS and if so that would of probably been more suited to some Xtra oomph

Looking here http://www.theyachtmarket.com/boats_for_sale/55582/ the beam is 3.05m compared to my beam, of, erm...... 3.11m which I suspect means "no"

HOWEVER, I have since found the original design specs from Sunseeker at home:

Max speed 51 knots with 2 x 502 MPI V8 445hp

So, if I want to go bonkers and re-engine in a few years I need to call Mr Sunseeker and ask if my boat will disintegrate.

But if I can squeeze out a few knots here or there I should be okay...

[larby]

445hp from a 502 mpi? I thought those were supposed to be 415 standard?

[Athito]

Originally Posted by larby

445hp from a 502 mpi? I thought those were supposed to be 415 standard?

dunno....just reading off the Sunseeker specs:

2 x 502 MPI V8 @ 451PS (332kW/445hp)

[JOSH]

Put some Big blocks in stef or thows 480 hps
would like that project.


Btw the pumps are back on not run yet as know one could get in today.

Josh

[Boatless-Again]

If you are willing to upgrade power, then purchase the Cummins QSB 480s, use a good reduction raito and the Arneson ASD8 Drives. This package cost less, weighs less and smokes almost zero compared to the Yanmars. You should see 50 knots.