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How much does added weight effect your speed ?

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Old 07-21-2004, 09:31 PM
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Default Re: How much does added weight effect your speed ?

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Originally Posted by Troutly
I see someone else was on www.faqs.org
How could he know?
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Old 07-21-2004, 09:41 PM
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Default Re: How much does added weight effect your speed ?

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Originally Posted by Jamie B.
How much does this boat weight ?
I have the original sea trial given to me by Val Jenkins when I picked up the boat at the factory. It says boat + fuel 4996 lbs, gross weight 5481 lbs.
It now has a heavier engine, merlin block and heads + supercharger. Also a #3 speedmaster with hydraulic steering. I tried to post a copy of the document but I am having difficulty.
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Old 07-21-2004, 09:43 PM
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Default Re: How much does added weight effect your speed ?

I read where every 100lbs will cost 1 mile per gallon so it has to take speed, I notice it with 4 big guys but not until top end. Fuel makes a huge difference, I always use 7 per gal also.
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Old 07-21-2004, 10:21 PM
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Default Re: How much does added weight effect your speed ?

Nothing is free it takes energy to move weight.
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Old 07-21-2004, 10:45 PM
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Default Re: How much does added weight effect your speed ?

Troutly'
I didn't follow your math. I got 194 -32=162 Divided by 32=5 mph. But again this assumes your are running a cat that is subject to weight. My fountain ran just as fast full maybe faster in the rough, 105-108 on gps
Jamie
Randy told me that my 42 with 900's 6's weighs about 10500lbs dry. But that was just off memory and the boat is 2001.
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Old 07-21-2004, 10:47 PM
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Default Re: How much does added weight effect your speed ?

The person who said "the best things in life are free" obviously never owned a boat or had his priorities screwed up because boating is the best thing in life but it is a long way from free.
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Old 07-22-2004, 08:27 AM
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Default Re: How much does added weight effect your speed ?

Square root of gross weight in pounds divided by horsepower x speed in stature mph = "k". Then add the weight and do it again. God it's early for this.
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Old 07-22-2004, 09:02 AM
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Default Re: How much does added weight effect your speed ?

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Originally Posted by BROWNIE
Square root of gross weight in pounds divided by horsepower x speed in stature mph = "k". Then add the weight and do it again. God it's early for this.
Assuming I am doing this right, I am coming up with a difference of 1.5 for "K", I am assuming that is = to 1.5mph lost when the weight was added. If I did this right than on a 4000lb boat running 107mph, 200lbs would equal approx 1.5 mph. Anyone else try this?
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Old 07-22-2004, 09:08 AM
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Default Re: How much does added weight effect your speed ?

Nothing scientific here but this is my understanding...... for every additional 8-10 lbs it takes an additional 1 hp... Most boats take anywhere from 15-20 hp to go an extra 1 mph... so based on these numbers, approx 150 - 200 lbs = a 1 mph loss... Makes sense, If I have a full tank of gas ( 700 lbs ) or a 1/4 tank ( 200 lbs ) I loose approx 2 mph.. Of course there are many other factors that effect this but for the most part, I would say this is a good rule of thumb..
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Old 07-22-2004, 09:08 AM
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Default Re: How much does added weight effect your speed ?

Well, when I went back and checked that it was only a difference of .3 mph. That doesnt seem right.
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