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19-01-2008, 05:20 PM
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#1
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Registered User
Join Date: Oct 2007
Posts: 1,374
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How Fast
With all the knowledge on here i would be interested to know what speed my Hunton Rib (sorry its not a hard boat ) will achieve when its finished.
Length 33 foot
Width 8 foot
Weight 2.3 Ton approx dry
Engins twin 496 Ho mercruisers XR Bravo drives
Power 850 HP
The hull is the same as the Hunton Maverick non stepped.
Boat should be in the water by March
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19-01-2008, 05:28 PM
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#2
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Registered User
Join Date: Mar 2004
Posts: 6,891
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According to your website - 90mph+
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19-01-2008, 05:45 PM
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#3
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Registered User
Join Date: Oct 2007
Posts: 1,374
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[QUOTE]
Quote:
Originally Posted by Matt
According to your website - 90mph+
[/QUOTE
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We live in hope.
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19-01-2008, 06:32 PM
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#4
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Registered User
Country: uk
Location: poole
Occupation: retail
Interests: sport and being lazy
Boat make: ring rib
Engines: merc xr2
Cruising area: bournemouth bay
Join Date: Jan 2006
Location: poole
Posts: 1,681
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Not wanting to throw a spanner in the works but my guess would be 76-79mph when first set up then with further adjustments with props tabs etc may be even drive's it may creep up to 82-85mph although this is all based on a weight of around 2500kg if you use the P1 formula I recon you would be lucky to see 80mph all a bit harsh I know, I had looked forward to the Brass Monkey to see how it all worked out...anyhow good luck
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i can na give her any more captain
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19-01-2008, 06:41 PM
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#5
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Registered User
Occupation: Champion Pie Eater
Boat name: On The Rocks
Boat make: Ring 21 marshan 17 four winns horizon, hydro 3 pointer, f2 cat, backdraft 22
Cruising area: Way up norf and Sarf coast areas
Join Date: Apr 2007
Posts: 1,619
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Hunton69
Remember for RBR its not gonna be all about the top speed but keeping up that average speed per leg
Especially when it chops up.
gaZ
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19-01-2008, 06:46 PM
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#6
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Registered User
Join Date: Oct 2007
Posts: 1,374
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Quote:
Quote:
Originally Posted by cfun
Not wanting to throw a spanner in the works but my guess would be 76-79mph when first set up then with further adjustments with props tabs etc may be even drive's it may creep up to 82-85mph although this is all based on a weight of around 2500kg if you use the P1 formula I recon you would be lucky to see 80mph all a bit harsh I know, I had looked forward to the Brass Monkey to see how it all worked out...anyhow good luck
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Not at all. After all thats why i asked the question it will be interesting to see what people think and then what it will achieve
Out of interest i thought the Scorpion ribs with 630Hp diesel engines weighing 3500kg were pulling 70 mph.
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19-01-2008, 06:48 PM
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#7
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Registered User
Country: uk
Location: poole
Occupation: retail
Interests: sport and being lazy
Boat make: ring rib
Engines: merc xr2
Cruising area: bournemouth bay
Join Date: Jan 2006
Location: poole
Posts: 1,681
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In order to be successful in the RB08 I think you will require one thing above all else.....................RELIABILITY
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i can na give her any more captain
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19-01-2008, 06:54 PM
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#8
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Registered User
Join Date: Oct 2007
Posts: 1,374
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Quote:
Quote:
Originally Posted by cfun
In order to be successful in the RB08 I think you will require one thing above all else.....................RELIABILITY
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Couldn't agree more. Thats why everything is new
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19-01-2008, 10:23 PM
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#9
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numbskull
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast
Join Date: Mar 2004
Location: South
Posts: 15,959
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80mph
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"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
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19-01-2008, 11:08 PM
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#10
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Guest
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Quote:
Originally Posted by Jon Fuller
80mph
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72mph
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19-01-2008, 11:18 PM
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#11
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Registered User
Join Date: Oct 2007
Posts: 1,374
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Quote:
Quote:
Originally Posted by skull666
72mph
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I will be if thats all it does
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20-01-2008, 12:49 AM
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#12
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Guest
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Quote:
Originally Posted by hunton69
I will be if thats all it does
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have you weighed it
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20-01-2008, 12:56 AM
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#13
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numbskull
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast
Join Date: Mar 2004
Location: South
Posts: 15,959
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I think the Hunton Maverick that John Evans refurbed, with 496 HOs ran about 80. I can't imagine why the rib would be any heavier, indeed, I would think it would be lighter, so at least 'as quick' with the same power.
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"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
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20-01-2008, 01:54 AM
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#14
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numbskull
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast
Join Date: Mar 2004
Location: South
Posts: 15,959
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Quote:
Originally Posted by hunton69
Out of interest i thought the Scorpion ribs with 630Hp diesel engines weighing 3500kg were pulling 70 mph.
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The stock, non stepped ones are I think capable of more like 62-63mph.
Mike Deacons light, stepped RB record boat (which almost certainly makes more than 630hp) is quicker, I believe as you say, around the 70 mark.
Also, 630hp is the total crankshaft hp of a pair of Yanmars (not propshaft hp), comparing like for like, you have 910hp, not 850.
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"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
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20-01-2008, 07:25 AM
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#15
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Registered User
Join Date: Oct 2007
Posts: 1,374
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[
Quote:
QUOTE=skull666;124338]have you weighed it
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[/QUOTE]
Not yet as the the boat isn't finished. What we do know is the bare hull weighs about 750 kg the engines abd drives 1100kg. The fuel tanks, seating and consol is unknown. Thats why i estimated 2300kg
That gives us a Power to weight ratio of 2.7Kg per HP
The Hunton XRS weighs around 5000kg with these engines pulls about 70mph
P1 supersport have P to W of 4.5kg per HP and they pull 80. That is why we estimated about 90mph.
Is there ways of working out top speed, very interested in to know if there is.
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20-01-2008, 08:56 AM
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#16
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Registered User
Country: UK
Location: Thorpe
Occupation: Mechanic
Boat name: spend it
Boat make: sr9 pascoe
Engines: 496 mag ho
Cruising area: Poole n solent
Join Date: Jun 2004
Location: Thorpe
Posts: 139
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hunton speed
i think john evans boat ran about 74-76 thats what niel said when i enquired about buying it surley it must b a lot heavier than the rib i reacon 78
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20-01-2008, 10:43 AM
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#17
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numbskull
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast
Join Date: Mar 2004
Location: South
Posts: 15,959
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Quote:
Originally Posted by hunton69
Is there ways of working out top speed, very interested in to know if there is.
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If you know exactly how fast John Evans boat went (not bar room talk) and exactly what it weighs (accurately, not a guess), you can establish a 'C' number for the design type which will closely resemble yours (not exactly the same, as C of G will differ, and you have different drive locations)
If you can then decide on a fairly sure total weight of yours, the Levi formula will give you a pretty accurate estimate on top speed.
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"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
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20-01-2008, 11:00 AM
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#18
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Registered User
Country: Job Centre
Location: In a box
Occupation: Chaos's gofer
Interests: Skiving
Boat make: Spectre 30
Engines: 2 x Promax 225
Cruising area: In the bath
Join Date: Mar 2004
Location: In a box
Posts: 5,201
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1 1/2 tons of fuel!
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Chaos for Moderator.
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20-01-2008, 12:00 PM
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#19
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Registered User
Country: uk
Location: poole
Occupation: retail
Interests: sport and being lazy
Boat make: ring rib
Engines: merc xr2
Cruising area: bournemouth bay
Join Date: Jan 2006
Location: poole
Posts: 1,681
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What weight is Mr Noisy as this is a 30' boat with 2x450hp petrol engines, although from all the various threads about it I understand the outdrive's and propellers continue to pose a setting up problem but it does crack 80 mph on a good day from what has been posted, is this not true
Hunton 69 your surmising ran similar to mine on guestimating performance and I also came up with less than the 80mph mark for a P1 P/W ratio but I still do not see anywhere near 90 even set up for a pier to pier run at 2300-2500kg although I can see you breaking into the 80's
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i can na give her any more captain
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20-01-2008, 07:15 PM
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#20
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Guest
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Quote:
Originally Posted by hunton69
I will be if thats all it does
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72mph set up for rb08 all the kit and fuel i would be happy with that, its a good hull and they are well built
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