How much trim
05-12-2016, 10:40 PM
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How much trim
Ok enuogh snickering!! On a more serious note how much trim at high speed? Let's say fresh water mabey one foot or so of chop. On the drive indicated gauge the first mark looks like about 1/4 then the second line looks to be about 1/3. I usually don't give it any more trim than that or perhaps just a touch. Chine walking scarse the **** out if me from time to time. Is this too much trim or not enough? Any thoughts or comments would be great!!
05-12-2016, 11:10 PM
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I'm not an expert so take this with a grain of salt...
I don't believe there is a set "setting" for trim -- from my experience I play with the trim almost constantly depending on what is in front of me. Now, I'm not on the ocean nor a huge body of water - I agree that chine walking stuff likewise scares the snot out of me too - it's like you are on the edge all the time - I'm not trying to race to make a living -just have as much fun as possible on the water. I too have questioned if I'm adjusting the trim correctly when I'm in 1-3' should I try to plow thru- trim all the way in or try to ride the top of the waves and watch my life flash in front of my eyes.
I'm sure there are better people that I that can help here
come on guys we need your expertise.
3pointstar
I don't believe there is a set "setting" for trim -- from my experience I play with the trim almost constantly depending on what is in front of me. Now, I'm not on the ocean nor a huge body of water - I agree that chine walking stuff likewise scares the snot out of me too - it's like you are on the edge all the time - I'm not trying to race to make a living -just have as much fun as possible on the water. I too have questioned if I'm adjusting the trim correctly when I'm in 1-3' should I try to plow thru- trim all the way in or try to ride the top of the waves and watch my life flash in front of my eyes.
I'm sure there are better people that I that can help here
come on guys we need your expertise.
3pointstar
05-13-2016, 12:57 AM
#3
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Gold Member
Hopefully a Velocity owner will chime in with better knowledge of the hull in question.
My general thoughts, when you buy a boat, check the trim gauge(s), they aren't always accurate. With the boat on the trailer, line the drives cav plate up with the hull bottom so they are parallel. Use a level, a straight edge or stand back a little and do it by sight. Put a temporary mark on the gauge with a felt pen or a bit of tape so now you can be sure where 'level' or 'zero ' trim is. Use this as your starting point.
With a non-stepped hull, find some nice water with loads of room to play. Get her running at near peak revs and zero trim, lift your tabs up slightly. Then start to to trim up and see what happens. Trim up very slightly, feel what the boats doing and then push for maximum revs. Remember, it takes a lot of space for a boat to reach full speed.
Don't be scared of chine walking, just be aware of it. Learn slowly, don't need to get the most out of a boat until you're totally accustomed to the way it handles and reacts. Things I found in the past that were shockers for chine walking are play in the steering, worn gimbal bearings and no tie bar (twin set up). Hydraulic steering is beautiful but expensive.
I think people place too much emphasis on the fastest speed their boat has ever achieved. They only get there once, usually with one person on board, no gear, low fuel, on a downhill saltwater lake with a tail wind! Just enjoy what you're comfortable with and learn as you go. Every boat is different in setup, balance, prop, x-dimension etc so there is no 100% answer.
As I said first, hopefully Velocity owners will speak up with more info on the particular model.
Enjoy!
RR
P.S. If you trim out too far, most boats will either start to porpoise or the props will blow out.
My general thoughts, when you buy a boat, check the trim gauge(s), they aren't always accurate. With the boat on the trailer, line the drives cav plate up with the hull bottom so they are parallel. Use a level, a straight edge or stand back a little and do it by sight. Put a temporary mark on the gauge with a felt pen or a bit of tape so now you can be sure where 'level' or 'zero ' trim is. Use this as your starting point.
With a non-stepped hull, find some nice water with loads of room to play. Get her running at near peak revs and zero trim, lift your tabs up slightly. Then start to to trim up and see what happens. Trim up very slightly, feel what the boats doing and then push for maximum revs. Remember, it takes a lot of space for a boat to reach full speed.
Don't be scared of chine walking, just be aware of it. Learn slowly, don't need to get the most out of a boat until you're totally accustomed to the way it handles and reacts. Things I found in the past that were shockers for chine walking are play in the steering, worn gimbal bearings and no tie bar (twin set up). Hydraulic steering is beautiful but expensive.
I think people place too much emphasis on the fastest speed their boat has ever achieved. They only get there once, usually with one person on board, no gear, low fuel, on a downhill saltwater lake with a tail wind! Just enjoy what you're comfortable with and learn as you go. Every boat is different in setup, balance, prop, x-dimension etc so there is no 100% answer.
As I said first, hopefully Velocity owners will speak up with more info on the particular model.
Enjoy!
RR
P.S. If you trim out too far, most boats will either start to porpoise or the props will blow out.
Last edited by rak rua; 05-13-2016 at 01:01 AM.
05-13-2016, 07:43 AM
#4
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Gold Member
Agree with the above. While on the trailer, trim the drive until it's level (or parallel) with the bottom of the boat and note where the trim gauge is at that point. This would be the minimum amount of trim you'll want to have.
Then, do the same with the tabs. Adjust them until they are both level (or in line) with the bottom of the boat. Note the gauge again, and make sure the gauges match. Note this mark. This is the most tab (or furthest down) you'll want to be.
Then run the boat and slowly increase the speed and start to bring the drive and tabs to the levels noted above. Once you get the hang of driving a pad bottom boat, you can start to trim up and pull the tabs up slowly until speed stops increasing.
As for chine walking, it takes practice. Once it starts, back off and start over. Don't drive through it. The goal is to prevent it, not drive out of it. Small countering steering movements is what it takes. You are balancing the boat on that pad.
Good luck!
Then, do the same with the tabs. Adjust them until they are both level (or in line) with the bottom of the boat. Note the gauge again, and make sure the gauges match. Note this mark. This is the most tab (or furthest down) you'll want to be.
Then run the boat and slowly increase the speed and start to bring the drive and tabs to the levels noted above. Once you get the hang of driving a pad bottom boat, you can start to trim up and pull the tabs up slowly until speed stops increasing.
As for chine walking, it takes practice. Once it starts, back off and start over. Don't drive through it. The goal is to prevent it, not drive out of it. Small countering steering movements is what it takes. You are balancing the boat on that pad.
Good luck!
05-13-2016, 10:45 AM
#7
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Gold Member
I learnt about chine walking 30 years ago in Australia with a 16' 90mph Bullet. They had a small runner plank and were notorious walkers from about 70 up. You had to learn to react and concentrate all the time. One thing that helped reduce it was a skier out the back but for the most part, drivers had to learn slowly.
Here's a rotten photo of me clowning around in the boat. This is what I mean by prop 'blows out' if you over trim.
Damn I had some fun in that thing!
RR
Here's a rotten photo of me clowning around in the boat. This is what I mean by prop 'blows out' if you over trim.
Damn I had some fun in that thing!
RR
05-13-2016, 03:20 PM
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Appreciate all the info. Some boat info as requested, 02 280 with a 469 mag HO for power. Bravo 1.50 gearing running a B1 26p prop. No Tabs and no Hydraulic Steering just yet but working on swinging that one soon.
Im thinking the trailer would need to be somewhat level but the boat doesn't sit perfectly level in the water. I guess one on plane should be pretty close to level . I enjoy the fact that this boat is a drivers boat and have a blast in it. Im not looking for the absolute best speed i can get just want to drive the boat the way it really needs to and do so in a safe manner. Looks like i need to get the level out before Sat. Thanks again guys, much appreciated.
Im thinking the trailer would need to be somewhat level but the boat doesn't sit perfectly level in the water. I guess one on plane should be pretty close to level . I enjoy the fact that this boat is a drivers boat and have a blast in it. Im not looking for the absolute best speed i can get just want to drive the boat the way it really needs to and do so in a safe manner. Looks like i need to get the level out before Sat. Thanks again guys, much appreciated.
05-13-2016, 03:45 PM
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Could be caused by loose steering. Do you have any play? Also will likely be worse in smooth water. Add a nice chop and it is faster and less prone to chine walk. It is also possible to under trim causing the boat to fall off the step, hit the chine and then bounce back.
What speed and conditions does it tend to chine walk? You mention 1 foot of chop, with your power you should be able to run fast with out chine walk. A 280 loves to run on top of light chop.
Also on the trim, bring it up to where it seems to be running nice and free at say 3500 to 4000 rpm and them bump the drive trim out. Literally just a bump, watch the speedo and tach and keep doing this till you stop gaining then bump it down a tad. It sounds complicated but after a while it is second nature. The gauge is a reference only, they are not that accurate.
One more thing, my 280 chine walked the most in flat water with only me in it. Add one passenger and it was much better. Always thought that strange but maybe it just improved the balance.
Padraig
What speed and conditions does it tend to chine walk? You mention 1 foot of chop, with your power you should be able to run fast with out chine walk. A 280 loves to run on top of light chop.
Also on the trim, bring it up to where it seems to be running nice and free at say 3500 to 4000 rpm and them bump the drive trim out. Literally just a bump, watch the speedo and tach and keep doing this till you stop gaining then bump it down a tad. It sounds complicated but after a while it is second nature. The gauge is a reference only, they are not that accurate.
One more thing, my 280 chine walked the most in flat water with only me in it. Add one passenger and it was much better. Always thought that strange but maybe it just improved the balance.
Padraig
