AT Trim Tab versus Boat Movement
07-27-2009, 04:30 PM
#11
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Can someone tell me about the vibration on the 37 AT? I had a vibration problem with the 358 Sonic with 30 Bravo 1 4 blade props. The vibration was of fairly short duration when coming out of the hole with a pretty heavy load. I switched to 5 blade hydro's and the problem was solved. Anyone have similar experiance with the 37 AT.
07-27-2009, 05:48 PM
#12
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I've never felt it before on any of the 37ATs, and I've been on a lot of them. (There was the one time when I ICBM'd a prop blade, but that's a different story.)
Clark claims he feels some vibration when getting on plane using the 4 blades and no tabs, but I think it has to do with how aggressive your props are tweaked and correspondingly how aggressively you have to accelerate to get out of the hole.
Just to compare to Sonic, and Fountain, and others with an integrated swim platform... when the boat is pitching up when coming on plane causing the swim platform to make a solid "cup" over the water; the air pressure building up from the exhaust will cause a vibration until you get the transom up out of the water. Attached pic shows example of this with my old 26' Sonic.
Clark claims he feels some vibration when getting on plane using the 4 blades and no tabs, but I think it has to do with how aggressive your props are tweaked and correspondingly how aggressively you have to accelerate to get out of the hole.
Just to compare to Sonic, and Fountain, and others with an integrated swim platform... when the boat is pitching up when coming on plane causing the swim platform to make a solid "cup" over the water; the air pressure building up from the exhaust will cause a vibration until you get the transom up out of the water. Attached pic shows example of this with my old 26' Sonic.
Last edited by Sydwayz; 07-27-2009 at 06:05 PM.
07-27-2009, 07:49 PM
#13
chuckbeecher
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I've never felt it before on any of the 37ATs, and I've been on a lot of them. (There was the one time when I ICBM'd a prop blade, but that's a different story.)
Clark claims he feels some vibration when getting on plane using the 4 blades and no tabs, but I think it has to do with how aggressive your props are tweaked and correspondingly how aggressively you have to accelerate to get out of the hole.
Just to compare to Sonic, and Fountain, and others with an integrated swim platform... when the boat is pitching up when coming on plane causing the swim platform to make a solid "cup" over the water; the air pressure building up from the exhaust will cause a vibration until you get the transom up out of the water. Attached pic shows example of this with my old 26' Sonic.
Clark claims he feels some vibration when getting on plane using the 4 blades and no tabs, but I think it has to do with how aggressive your props are tweaked and correspondingly how aggressively you have to accelerate to get out of the hole.
Just to compare to Sonic, and Fountain, and others with an integrated swim platform... when the boat is pitching up when coming on plane causing the swim platform to make a solid "cup" over the water; the air pressure building up from the exhaust will cause a vibration until you get the transom up out of the water. Attached pic shows example of this with my old 26' Sonic.
I-Lean(serial #1 with step) and the other 37 with boxes that I have experience with never did it. Those you could always just bring the power right on up and no problem...right on up not slamming them..
BUT tabs always helps any of them jump up easier.
As for indicators and indications..just remember any thing hanging off the back:
if it goes down the bow goes down
if it goes up the bow goes up
remember that and you can do it with out any indicators just takes practice
I was taught by someone, with racing experience, years ago how to handle a quartering sea or strong wind with just splitting the drives to level the boat
and if the boat is launching it takes the load off the drive hitting first.
Last edited by chuckbeecher; 07-27-2009 at 07:58 PM.
07-27-2009, 08:03 PM
#14
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No vibration at all on the A/T ! Possibly prop slip on the 4 blade 32's in fresh water, but I am yet to experience vibration at all. Heavy load or light load no vibration, went to 5 blade Hydros due to fresh water and elevation and they bite real nice, but still looking to try a pair of labbed 30's just to see the numbers.
Can someone tell me about the vibration on the 37 AT? I had a vibration problem with the 358 Sonic with 30 Bravo 1 4 blade props. The vibration was of fairly short duration when coming out of the hole with a pretty heavy load. I switched to 5 blade hydro's and the problem was solved. Anyone have similar experiance with the 37 AT.
07-27-2009, 09:39 PM
#15
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No vibration at all on the A/T ! Possibly prop slip on the 4 blade 32's in fresh water, but I am yet to experience vibration at all. Heavy load or light load no vibration, went to 5 blade Hydros due to fresh water and elevation and they bite real nice, but still looking to try a pair of labbed 30's just to see the numbers.
Brian, My Maximums vibrated not the four blades. I had the Max re-balanced by Throttle Up and it fixed it. I think is has a lot to do with trying to run too big of a wheel without having them balanced properly.
Laszlo, labbed 30's suck. Also, AT's have high slip. That is the bottom line and there little to do to change it. I believe it has to do with the flow of the water off the large front step, thru the pad, and then off the back. However I am no expert.
The only boat that I knew that had low slip was Thunder Roy's boat. The one in the classified with 500's and boxes. That boat had a blue printed bottom and the boxes pushed the props back far enough that the wheels ran in cleaner water, thus the reason for less slip.
Please, lets not have a box conversation!
Last edited by crb76; 07-27-2009 at 09:49 PM.
07-27-2009, 10:46 PM
#16
Vibration is prop specific. Has nothing to do with the boat or the way you bring it up. You can mitigate it with tabs. I have been known to try more than one set of props!
Brian, My Maximums vibrated not the four blades. I had the Max re-balanced by Throttle Up and it fixed it. I think is has a lot to do with trying to run too big of a wheel without having them balanced properly.
Laszlo, labbed 30's suck. Also, AT's have high slip. That is the bottom line and there little to do to change it. I believe it has to do with the flow of the water off the large front step, thru the pad, and then off the back. However I am no expert.
The only boat that I knew that had low slip was Thunder Roy's boat. The one in the classified with 500's and boxes. That boat had a blue printed bottom and the boxes pushed the props back far enough that the wheels ran in cleaner water, thus the reason for less slip.
Please, lets not have a box conversation!
Brian, My Maximums vibrated not the four blades. I had the Max re-balanced by Throttle Up and it fixed it. I think is has a lot to do with trying to run too big of a wheel without having them balanced properly.
Laszlo, labbed 30's suck. Also, AT's have high slip. That is the bottom line and there little to do to change it. I believe it has to do with the flow of the water off the large front step, thru the pad, and then off the back. However I am no expert.
The only boat that I knew that had low slip was Thunder Roy's boat. The one in the classified with 500's and boxes. That boat had a blue printed bottom and the boxes pushed the props back far enough that the wheels ran in cleaner water, thus the reason for less slip.
Please, lets not have a box conversation!
Gents, don't be afraid to try a couple different set of props if you feel froggy. Brett at BBlades knows his stuff and can help you tune until your heart or wallet is content. Personally, I just pick an all around great set of props, and stick with them. I have two pair, stock 4 blades and labbed 4 blades. I think I have run the labbed props for a total of 1 day. They just stay in the boxes nice and pretty.
Clark's boat is heavier than most of the other late model 37ATs due to his custom cabin configuration, but it still runs 90mph GPS with Herrings behind the 525/XRs.
07-27-2009, 10:58 PM
#17
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No vibration at all on the A/T ! Possibly prop slip on the 4 blade 32's in fresh water, but I am yet to experience vibration at all. Heavy load or light load no vibration, went to 5 blade Hydros due to fresh water and elevation and they bite real nice, but still looking to try a pair of labbed 30's just to see the numbers.
07-28-2009, 08:59 AM
#18
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That was us, we decided to stay south due to weather so we took a trip down the Maumee, got lots of looks for sure.
Just to have fun, should we Box or not ? As that would put the props in cleaner water.
Just to have fun, should we Box or not ? As that would put the props in cleaner water.
Last edited by laszlo01; 07-28-2009 at 10:31 AM.
07-28-2009, 04:57 PM
#19
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Just for grins, next time you're out, trying raising the drive on the high side when you have a lean instead of dropping the tab on the low side and let me know what you think.
