Reply
 
Thread Tools Search this Thread
 
Old 13 December 2003, 17:11   #1
Member
 
Country: UK - England
Town: isles of scilly
Boat name: Still Miss behavin
Make: Ribcraft
Length: 6m +
Engine: 250 suzuki
Join Date: Dec 2003
Posts: 129
more speed

hi i'm after some info regarding getting more speed out of my rib.
The current set up is a 5.5m delta dash powered by twin suzuki dt 65's with standard 16' pitch 3 blade alloy props set on the lowest height on the transom. Currently i get 36 knots (gps) flat out at 5300rpm on the tachos.
I don't really want to change pitch drastically to get speed at the cost of acceleration But i'm thinking that stainless props would help (anyone know how much) and also been told to raise the engines on the transom by a hole to reduce drag.?
I'm after over 40 knots really so has anyone got any tips advice to get this performance.
thanks in advance
__________________
behavin is offline   Reply With Quote
Old 13 December 2003, 19:05   #2
Member
 
gtflash's Avatar
 
Country: UK - England
Town: southampton
Boat name: TOP CAT 2
Make: Scorpion 8.1
Length: 8m +
Engine: 250hp HO
Join Date: Aug 2003
Posts: 1,803
not a 100% sure but i think if you swap your thick bendy ally prop for an equal stainless item typically people see a gain of 2-3mph. I addes 2 blades kept the same pitch and changed to stainless and didnt loose or gain any speed at all so hopefully its somewhere near right
__________________
gtflash is offline   Reply With Quote
Old 13 December 2003, 20:43   #3
Member
 
Pete7's Avatar
 
Country: UK - England
Town: Gosport
Boat name: April Lass
Make: Moody 31
Length: 9m +
Join Date: Aug 2001
Posts: 4,951
Blimey I am astonished that you manage to get 36 knots, thats going some. You could change to S/S which would then let you raise the engine a hole but I am not sure the benefit would be worth the cost or trouble. The higher the props the easier they will ventilate everytime you go over a wave and the props come near the surface and with twin engines thats a lot more often than a single.

Big gains in speed require hp and fuel. There was a Delta for sale on Hayling Island with a 150 V6 merc on the back end a few years ago. That would have been very quick (and scary)

Pete
__________________
Pete7 is offline   Reply With Quote
Old 14 December 2003, 01:41   #4
Member
 
Country: Canada
Town: cowichan valley
Join Date: Dec 2000
Posts: 70
do lift the engine up. this will decrease the drag and allow more rpms. every boat is differant and only trying will tell. i raised our engines all the way and got 6 knots. did have to buy new props though cause of the rpms. the boat handles better and does not blow out in corners or come of the water over every wave. good luck
__________________
eksrae
eksrae 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




All times are GMT. The time now is 09:48.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.