Reply
 
Thread Tools Search this Thread
 
Old 13 September 2007, 01:11   #1
Member
 
Country: UK - England
Town: Aylesbury/Lymington
Boat name: Farfetched
Make: Solent
Length: 6m +
Engine: 150hp Optimax
MMSI: 235021048
Join Date: Apr 2004
Posts: 859
New / Spare Prop

Running 21" Laser on my 150 opti and 6.5M Solent. Want to up my WOT speed - yes, I'm a sad bugger. Don't pull anything. This is about the need for speed. No real need to be fast out of the hole - wife tells me off when I do anyway. But when near WOT she is hanging on and the Opti 'deafens' me!!!!

Currently about 45/46K on gentle chop with 1/4 tank and 2 adults. Ideas please?

Thanks as ever
__________________

__________________
brucehawsker is offline   Reply With Quote
Old 13 September 2007, 03:41   #2
Member
 
Pete7's Avatar
 
Country: UK - England
Town: Gosport
Boat name: April Lass
Make: Moody 31
Length: 9m +
Join Date: Aug 2001
Posts: 4,850
Bruce, you need to know what the max revs are at your current top speed, but I recon your pretty close to the biggest prop you can turn now.

If you want to go faster you need a bigger engine or loose some weight, out of the boat that is.

Pete
__________________

__________________
.
Ribnet is best viewed on a computer of some sort
Pete7 is offline   Reply With Quote
Old 13 September 2007, 04:21   #3
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
Quote:
Originally Posted by Pete7 View Post
If you want to go faster you need a bigger engine or loose some weight, out of the boat that is.

Pete
Loose the Wife and run on fumes, take that horse shoe life ring off the back (should decrease your drag a little) and off you go

Be sure to let us all know how you get on.
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 14 September 2007, 09:28   #4
Member
 
Country: UK - England
Town: Aylesbury/Lymington
Boat name: Farfetched
Make: Solent
Length: 6m +
Engine: 150hp Optimax
MMSI: 235021048
Join Date: Apr 2004
Posts: 859
I need to lose weight personally anyway
__________________
brucehawsker is offline   Reply With Quote
Old 14 September 2007, 12:56   #5
Member
 
Country: UK - Wales
Town: West Wales
Make: Vipermax 5.8, SR4.7
Length: 5m +
Engine: 150 Opti, F50EFi
Join Date: Sep 2005
Posts: 6,298
Quote:
Originally Posted by brucehawsker View Post
..... But when near WOT she is hanging on and the Opti 'deafens' me!!!!
Surely, you don't expect more speed and less noise?

If you want less 'deafening noise', better get rid of the Opti.
__________________
Downhilldai is offline   Reply With Quote
Old 14 September 2007, 13:05   #6
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,841
I find the 'prop advice' on this site so hit and miss that it's close to no use at all. I have the same engine and the same prop as yourself on a 6.5m Vipermax. I get 40knots and that's the lot, I'm surprised that you're getting 6knts more. No way could I run a 23P prop, it would kill the boat. I'd struggle to get on the plane.
__________________
Mollers is offline   Reply With Quote
Old 14 September 2007, 13:55   #7
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
Quote:
Originally Posted by Mollers View Post
I find the 'prop advice' on this site so hit and miss that it's close to no use at all. I have the same engine and the same prop as yourself on a 6.5m Vipermax. I get 40knots and that's the lot, I'm surprised that you're getting 6knts more. No way could I run a 23P prop, it would kill the boat. I'd struggle to get on the plane.
They're completely different shapes of Hull, the 6.5m Solent in nearer 7m in length BTW, but has a much narrower beam than the Vipermax. That'll mean the Solent will go faster, but have a much harder ride. It's probably a lighter RIB as well.

I'm hoping my 6.2 Vipermax will top out at 45 knotts with a 150 on. The beam is narrower than the 6.5's so hope it'll be a faster hull.
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 14 September 2007, 16:45   #8
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,841
[QUOTE=Hightower;218754] They're completely different shapes of Hull, the 6.5m Solent in nearer 7m in length BTW, but has a much narrower beam than the Vipermax. That'll mean the Solent will go faster, but have a much harder ride. It's probably a lighter RIB as well.

If it's nearly 7m and doing 45+knts with a 150 Opti on the back it must be made of tissue paper.
__________________
Mollers is offline   Reply With Quote
Old 14 September 2007, 17:05   #9
Member
 
Hightower's Avatar
 
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,855
[QUOTE=Mollers;218794]
Quote:
Originally Posted by Hightower View Post
They're completely different shapes of Hull, the 6.5m Solent in nearer 7m in length BTW, but has a much narrower beam than the Vipermax. That'll mean the Solent will go faster, but have a much harder ride. It's probably a lighter RIB as well.

If it's nearly 7m and doing 45+knts with a 150 Opti on the back it must be made of tissue paper.
I can't quote on speeds for the Solent, but the hull design is based on a Tohatsu hull I believe. This could be opening a can of worms here

It is quite an efficent design and have been in one at full chat with an HO 200 Etec on the back. Yes, it did hurt
__________________
Andy

Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
Hightower is offline   Reply With Quote
Old 15 September 2007, 08:47   #10
Member
 
Country: UK - England
Town: Aylesbury/Lymington
Boat name: Farfetched
Make: Solent
Length: 6m +
Engine: 150hp Optimax
MMSI: 235021048
Join Date: Apr 2004
Posts: 859
OK. Can confirm that with two blokes (13.5st and 12st) and one quarter of a tank 40 litres with our six pods, anchor, safety kit etc we averaged (I have numbers in front of me) 45.78k according to the GPS on a two way run WOT from approx the Lymington Sailing Platform to Cowes Roads in a light chop (F2/3 - sea condition mild). No it doesn't hurt if you keep a hand on the trim and trim down for the rougher bits. This is with a clean bottom - polished myself (no, the boat, you idjut!) and the engine nice and warm. Temperature about 68c, sunny.

Kev from Solent got it up to 49.1 a while back with the two of us on board with a about a 3 knot current going with us according to the electronic chart - so that is 46k.

I like the noise!!
__________________

__________________
brucehawsker is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 18:30.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.