Sv29/ilmor 725/indy
10-08-2014, 10:18 PM
#281
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10-09-2014, 09:26 AM
#282
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The original concept was to put a wing either side but it would be quite difficult to mount without taking a mould of the deck so that i had something to work with back here in England. As the majority of the torque reaction is done by the top end of the fin they would still need to be fairly tall, they also couldn't be mounted vertically on the outside, they would need to be mounted at approximately 30% for best results, which would make it as awkward as a bat boat to moor up at the docks. It is also much easier to make a single vertical wing steerable. I will be using it fixed to start with to prove the theory.
Peter
10-09-2014, 09:28 AM
#283
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10-09-2014, 09:49 AM
#284
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The SV29 is far from ill handling up to mid 90's it is pretty planted but being a surface drive there is very little left in the water beyond these speeds, if you catch a wash from the side it will start to chine walk as there is nothing left in the water for it to react against, if it were an immersed propellor boat you can counter steer to correct it. As the surface drive does not have anywhere near as much sideways grip or leverage steering inputs don't damp out the chine walk anywhere near as well. The tail fin should damp out the chine walk and allow us to go even faster more comfortably and safely, using aerodynamics is much more efficient than dragging something through the water it also has the benefit of the faster you go the better it works.
Peter
10-09-2014, 10:12 AM
#285
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Hi Chris,
The SV29 is far from ill handling up to mid 90's it is pretty planted but being a surface drive there is very little left in the water beyond these speeds, if you catch a wash from the side it will start to chine walk as there is nothing left in the water for it to react against, if it were an immersed propellor boat you can counter steer to correct it. As the surface drive does not have anywhere near as much sideways grip or leverage steering inputs don't damp out the chine walk anywhere near as well. The tail fin should damp out the chine walk and allow us to go even faster more comfortably and safely, using aerodynamics is much more efficient than dragging something through the water it also has the benefit of the faster you go the better it works.
Peter
The SV29 is far from ill handling up to mid 90's it is pretty planted but being a surface drive there is very little left in the water beyond these speeds, if you catch a wash from the side it will start to chine walk as there is nothing left in the water for it to react against, if it were an immersed propellor boat you can counter steer to correct it. As the surface drive does not have anywhere near as much sideways grip or leverage steering inputs don't damp out the chine walk anywhere near as well. The tail fin should damp out the chine walk and allow us to go even faster more comfortably and safely, using aerodynamics is much more efficient than dragging something through the water it also has the benefit of the faster you go the better it works.
Peter
10-10-2014, 03:01 AM
#286
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The boat only weighs 5200lbs with fuel and crew, stability is very good up to mid 90's the tip of the fin is approximately 9ft 6 higher than the roll centre and i am pretty confident the boat will run upwards of 110mph but i like to have all my ducks in a row before pushing the envelope, We also boat mostly on our own with no rescue facilities so caution has to be the priority.
Peter
10-12-2014, 04:14 PM
#287
Hi Peter,
Congrats with your project.
If I remember correct you shortened the skeg on your lower unit? Do you think this may have some effect on the sensitivity to chine walk at high speed, and less possibility to "drive through it" as they say.
Cheeers, Toffen
Congrats with your project.
If I remember correct you shortened the skeg on your lower unit? Do you think this may have some effect on the sensitivity to chine walk at high speed, and less possibility to "drive through it" as they say.
Cheeers, Toffen
Last edited by Toffen; 10-12-2014 at 04:27 PM.
10-14-2014, 08:54 AM
#289
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I remember watching the live feed for the LOTO shootout(in 2012 I believe) and a V29 was chine walking so badly you could see the bottom of the boat! However, he did pull out of it, lay back in it and still did almost 90 if I remember right.
10-14-2014, 09:17 AM
#290
Sv29/ilmor 725/indy
Hi,
I have read they almost made 100 mph with a 565. I have not heard anything about bad handling, the opposite in fact. But running in excess of 100 with a single engine is a balancing act anyway.
Check these mad guys: 99 Psycho Clowns running a 22 feet boat with a single 1350
Cheers, Toffen
I have read they almost made 100 mph with a 565. I have not heard anything about bad handling, the opposite in fact. But running in excess of 100 with a single engine is a balancing act anyway.
Check these mad guys: 99 Psycho Clowns running a 22 feet boat with a single 1350
Cheers, Toffen
