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Old 20-09-2008, 10:56 PM   #1
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need 10mph

is 10 mph achieveable somehow or is it a new engine?? if so how many more geee geeeeees!

getting 50mph but would like to hit mile a minute... 200opti 21" laser prop several inches below transom! not too keen to lift engine up high as warped hull and dont want to keep facing the wrong way plus id have to cut the transom mould for saddle!

shall i start saving again?
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Old 21-09-2008, 09:16 AM   #2
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Sounds like you need a different motor to me... especially if you want to keep any kind of hole shot. The only things you could play around with are engine height and prop type, 10mph is quite a lot!
To save you altering the transom you could perhaps fit a lifter to get a few more inches height? I still don't know if you'd see 10mph with just that though.
Any idea what speed the hull is capable of? I remember trying to make my ring16 faster when i was younger, didn't matter how many hp i strapped to the back, it just became more and more unstable for the sake of 1 or 2mph.

Someone else may have a better suggestion though!

James
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Old 21-09-2008, 01:01 PM   #3
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Larby
I see your profile shows you have a new boat!

gaZ
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Old 21-09-2008, 02:11 PM   #4
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new boat!

It does indeed! Came across to blighty for the day yesterday and went out for a spin... had a great time at drivers and bought myself aquaholic!

I'm going to completely strip out the interior and rebuild over the winter, think i might start a thread now to see what suggestions people have

Was also great to meet some other people from here, TD, JF, Blufin etc etc.

Pash is dropping her down to portsmouth as we speak and i'm hoping to have her over here on tuesday, feel like christmas has come early!

James
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Old 21-09-2008, 02:22 PM   #5
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Maybe have a chat with Steve Hutch here, as he owned your boat with a twin very quick set up.
Aye, good crowd down at that Drivers i'm dropping in Next Sat Morning to have a look at Blinddogs New boat.
Sorry going a bit off thread here.

gaZ
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Old 21-09-2008, 03:11 PM   #6
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I'm busy next week gaz so will miss ya.
Was a nice time at "playgroup" this week even had some marshmellow cones & gingerbread men tooo.
James enjoy the new ride have a project thread up & running soon - you know it makes sense
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Old 21-09-2008, 04:01 PM   #7
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[
Was a nice time at "playgroup" this week even had some marshmellow cones & gingerbread men tooo



Do you mean Jon and a twin brother??

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Old 21-09-2008, 04:26 PM   #8
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Mmmmmh never thought of that slant. Nah ikle ones with smarties for buttons.
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Old 21-09-2008, 05:28 PM   #9
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they were nice gingerbread men actually! I'm hoping to have her here for tuesday so i'll start a thread with lots of nice piccies tonight probably, i need lots of opinions and suggestions on lots of things!

The guy who started this tread is gonna kill us!

James
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Old 22-09-2008, 09:26 AM   #10
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Larby is right, 10mph is a hell of a lot to gain on a set up.

Ask anyone that has ever come to Records Week, you see people every year trying to make speed up during the week, most the time an increase of 1 or 2 mph is the max.
You don't sound as though you have the set up there at the moment but still 10 mph is a long process.

Start by lifting the motor, setting the motor back, racing prop, strip the weight out of the boat, especially the front, you need bow lift to go fast.

Someone said change motor, if your hull is warped i'd change the hull!!
If you put some more information up of your set up and what boat it is it might be more useful.
Will
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Old 22-09-2008, 02:35 PM   #11
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Quote:
Originally Posted by willwood6 View Post
Larby is right, 10mph is a hell of a lot to gain on a set up.

Ask anyone that has ever come to Records Week, you see people every year trying to make speed up during the week, most the time an increase of 1 or 2 mph is the max.
You don't sound as though you have the set up there at the moment but still 10 mph is a long process.

Start by lifting the motor, setting the motor back, racing prop, strip the weight out of the boat, especially the front, you need bow lift to go fast.

Someone said change motor, if your hull is warped i'd change the hull!!
If you put some more information up of your set up and what boat it is it might be more useful.
Will
Its a scorpion 7.5m rib. It cruises at almost flat out easily so has great average speed but i am pretty dissapointed with the top end speed and thrill factor... i thought the comfort would keep me happy and most of time it does but still wanna go faster!

Think the hull is rated to 250hp so im quite a bit under that! But if i stuck another 25 or 50 horses on the back therefore not tuning the setup and making it a monster to drive would i likely achieve 60mph? or just spend a fortune and get a small increase?
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Old 22-09-2008, 04:33 PM   #12
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Adding horsepower to a shit set up would be a complete waste of time, money and effort.
You'll create something that is impossible to drive.

Set up takes longer and more effort but you'd end up with a more enjoyable boat to drive and it will be faster without spending loads of cash on engines. Then when the set up is right buy a bigger engine when you decide your still not going fast enough, which you will.

Boats are very hard work but worth it when you get them right!
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Old 22-09-2008, 05:04 PM   #13
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Quote:
Originally Posted by glen76 View Post
Its a scorpion 7.5m rib. It cruises at almost flat out easily so has great average speed but i am pretty dissapointed with the top end speed and thrill factor... i thought the comfort would keep me happy and most of time it does but still wanna go faster!

Think the hull is rated to 250hp so im quite a bit under that! But if i stuck another 25 or 50 horses on the back therefore not tuning the setup and making it a monster to drive would i likely achieve 60mph? or just spend a fortune and get a small increase?
I had a Scorpion 7.5 with a Yam 200 HPDI (Ice Kiddie owns this boat now). It topped out at just under 50 kts iirc. Thats 54mphish. I'm sure you could bolt a 225 Opti on the back without screwing up the handling but whether you'd gain enough to make it worthwhile is another question. Its probably a question to ask Scorpion themselves.

Aside from that, just get yer bowie knife ready and go out in rougher seas. You'll get all the thrill factor you want even at 50mph.
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Old 22-09-2008, 05:47 PM   #14
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Quote:
Originally Posted by Atlantic Xpat View Post
I had a Scorpion 7.5 with a Yam 200 HPDI (Ice Kiddie owns this boat now). It topped out at just under 50 kts iirc. Thats 54mphish. I'm sure you could bolt a 225 Opti on the back without screwing up the handling but whether you'd gain enough to make it worthwhile is another question. Its probably a question to ask Scorpion themselves.

Aside from that, just get yer bowie knife ready and go out in rougher seas. You'll get all the thrill factor you want even at 50mph.
what prop was that with???
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Old 13-10-2008, 08:30 PM   #15
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Seems Jf was right!! I found about 10 litres of water in the hull! Without that and with new trim tabs ive got the speed up to 46.5 knots! very happy. Pullining 5000-5100rpm!

the speed does actually seem to increase with trim tabs as i can keep the attitude of the nose controlled but trim engine up, the engine revs a little higher and speed increases!! With tabs fully up it seems to start heading towards buttom moon!

I did find with high engine trim and a little tab the back seemed to crab..... fet like it may swap ends but not really being a high speed driver i didnt know if i imagined it! any advice appreciated!
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