Installed -2 Imco Shorties on a 38 Fever, Picked up 5 mph AT LEAST
01-29-2006, 09:53 AM
#111
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Re: Installed -2 Imco Shorties on a 38 Fever, Picked up 5 mph AT LEAST
Originally Posted by pachangalpina
My performance report says 18.5" but I measure 16.5". I am not sure if somebody put in the specs for a TRS or if this is really correct. I could see my measurement being off a little but not 2". Nauti...did you measure yours of just pull that spec from the perf report.
I measured mine with the transom assembly off using the template. I measured from the crankshaft centerline to the projected hull line. I used a straight edge on the bottom to project the hull and measured straight down from the crank C/L.
I just went out and rechecked with the transom assembly in place and came up with the same measurement.
I did not see any signs that my transom had been redone or the cutouts changed. I thought the 18.5" was either a typo or what they were using for the TRS.
I measured mine with the transom assembly off using the template. I measured from the crankshaft centerline to the projected hull line. I used a straight edge on the bottom to project the hull and measured straight down from the crank C/L.
I just went out and rechecked with the transom assembly in place and came up with the same measurement.
I did not see any signs that my transom had been redone or the cutouts changed. I thought the 18.5" was either a typo or what they were using for the TRS.
I'm not sure how to measure it , can that be explained
how you did it ?
01-29-2006, 08:54 PM
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Re: Installed -2 Imco Shorties on a 38 Fever, Picked up 5 mph AT LEAST
Nauti, I don't think the information you are getting on your "x" dimension is correct. An older Bravo boat with your "x" dimension and 3 blade props would probably never go on plane. I'm betting you probably have a 16-1/2" "x"
dimension versus the 18-1/2" that you speak of. 18's were commonly used on TRS set ups where the outdrive is much longer.
To check your "x" dimension, measure from the bottom of the transom plate to the top of the notch in your transom. Then from the top of the notch to the bottom of the boat in the direct centerline of the outdrive. The two combined measurements should equal 7-1/2". If so, you have a 16-1/2"
"x" dimension. ("X" dimension is just the distance from crankshaft centerline to the bottom of the boat. Crankshaft centerline to the bottom of the transom plate is 9".Plus, the 5" to the notch and the 2-1/2" to the bottom equals 16-1/2".)
Please measure and post results. If you are at 16-1/2", you may benefit from a shorter drive in the 70 - 90 mph range.
dimension versus the 18-1/2" that you speak of. 18's were commonly used on TRS set ups where the outdrive is much longer.
To check your "x" dimension, measure from the bottom of the transom plate to the top of the notch in your transom. Then from the top of the notch to the bottom of the boat in the direct centerline of the outdrive. The two combined measurements should equal 7-1/2". If so, you have a 16-1/2"
"x" dimension. ("X" dimension is just the distance from crankshaft centerline to the bottom of the boat. Crankshaft centerline to the bottom of the transom plate is 9".Plus, the 5" to the notch and the 2-1/2" to the bottom equals 16-1/2".)
Please measure and post results. If you are at 16-1/2", you may benefit from a shorter drive in the 70 - 90 mph range.
01-31-2006, 10:22 AM
#113
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Re: Installed -2 Imco Shorties on a 38 Fever, Picked up 5 mph AT LEAST
would I be giving up anything in handling or getting on plane
right now this drive height boat jumps on plane way more than I need before propping .
right now this drive height boat jumps on plane way more than I need before propping .
02-02-2006, 10:54 AM
#114
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Re: Installed -2 Imco Shorties on a 38 Fever, Picked up 5 mph AT LEAST
Nauti when you rasie your drive height you will lose leverage on the boat , will that effect handling & planing ? Maybe! Depends on how much you go up & if you can tune the ride attude with props . I think every boat has a sweet spot , and that changes with speed & power combo .
Instead of talking X diamention measure how far the center of the prop shaft is under the boat with the drives hanging streight , this puts everthing in simple terms for everyone to understand .
Instead of talking X diamention measure how far the center of the prop shaft is under the boat with the drives hanging streight , this puts everthing in simple terms for everyone to understand .
02-03-2006, 02:26 AM
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Re: Installed -2 Imco Shorties on a 38 Fever, Picked up 5 mph AT LEAST
Originally Posted by racinfever
Nauti when you rasie your drive height you will lose leverage on the boat , will that effect handling & planing ? Maybe! Depends on how much you go up & if you can tune the ride attude with props . I think every boat has a sweet spot , and that changes with speed & power combo .
Instead of talking X diamention measure how far the center of the prop shaft is under the boat with the drives hanging streight , this puts everthing in simple terms for everyone to understand .
Instead of talking X diamention measure how far the center of the prop shaft is under the boat with the drives hanging streight , this puts everthing in simple terms for everyone to understand .
I went under the boat while it's on hydrohoist by myself
it's hard to get straight edge measurment while hanging over the water . But it looked that 16.5xd , you are probily right .
thinking about sportmaster storties -2's would they make the
trim settings normaly a lower numder setting than before with regular height drives? my drive height now allows the boat to plane easy without tabs , and can hold plane at just over 2500 rpm getting up launching at 3000 rpm with my old 520's
now with my 650's should be even esaier still!
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