Who has the fastest tin??

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Alumacraft
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Who has the fastest tin??

Post by Alumacraft »

Boat weighs 280lbs I dont know why you dont believe me

fastcajun
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Who has the fastest tin??

Post by fastcajun »

the reason i say that, is a flat bottom is faster than a vhull due to dynamics. there are 12-14ft flat bottoms down here with 3 cyl 40 mercs that only run 40. Also you have alot of motor hanging down below the bottom(drag). but hey if it does then congrats man. I know my flat runs about 37-40 depending on the weight in it and water conditions and that is with a hopped up 40 tohatsu. But i can also run that fast through 4 in of water. :mrgreen:
2010 1644 Alweld tunnel runnin from a 93 Tohatsu Mega

fastcajun
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Who has the fastest tin??

Post by fastcajun »

i gues i shouldnt have said "dont believe you" its hard to believe
2010 1644 Alweld tunnel runnin from a 93 Tohatsu Mega

JustDucky
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Who has the fastest tin??

Post by JustDucky »

Alumacraft's boat looks fast to me ... but maybe its the hod rod red paint!

3dees
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Who has the fastest tin??

Post by 3dees »

seeing that it's a tiller then you probably don't have a speedo, so how are you measuring your speed? is that gps. sorry, but I'll say what everyone is thinking. numbers just don't add up. in one post you said 50mph, then in another it's mid 50's. imo, that set up is not capable of that speed. as for insurance, well how much is that rig worth if someone rammed you on the road? got any idea how much to replace a shaft if you hit someting? I pay 300.00 per year on a new tin with a 115 optimax. it would probably cost you less than 100.00 per year. it's just silly and irresposible to run a nice boat like that without insurance. of course it's your boat and money, so whatever.

reedjj
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Who has the fastest tin??

Post by reedjj »

My little 1542 had the 25merc on it. That is what it was rated for, and like I said earlier it ran 31-32mph on GPS. By no means was that anywhere near dangerous or irresponsible. I would have felt completely comfortable going 10-15mph faster no problem.

I wouldnt have even thought 2x about putting a 40 hp on it if I could have found one at a decent price. That would have been 15hp over what it was rated for, and I bet it would have ran close to 45mph if set up properly.

Alumacraft is only 5hp over what its rated for and he's running a 2 stroke which is lighter than the fourstroke by alot! To me that is the perfect fit.

I would like to see a video of it running 50+!

fastcajun
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Who has the fastest tin??

Post by fastcajun »

that motor is very capable of 60 mph, IF its setup right. i believe he has to much drag hanging below his hull and a v-hull is an optimum hull for speeds do to it pushing water vs. a flat bottom gliding over the water.
as far as overpowering a boat vs insurance. I was never asked what size motor I had, They asked how much i want it insured for. also if you read that plate on the back, it says max RECOMENDED hp. just some food for thought
2010 1644 Alweld tunnel runnin from a 93 Tohatsu Mega

FuzzyGrub
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Who has the fastest tin??

Post by FuzzyGrub »

fastcajun wrote:i gues i shouldnt have said "dont believe you" its hard to believe

FWIW, I'd say the same. My initial gut "thought" would have been "low to mid-40's". When it doesn't pass my "gut feel", I enter data into a prop slip calculator. Assuming merc max alum prop pitch of 13", gear ratio on the engine, and going 500 rpms over the high wot rpm, to hit 55mph, would be almost a negative 40% slip. I could have numbers off, so posted what i used along with result. But that is a significant descrepency, so would not get too upset when people question it or how it was measured.

Ratio: 1.83
Pitch: 13
rpm: 6000
Theoretical speed: 40
Actual: 55
Slip: -37%

I am not calling you out, in any shape or form. Just showing why people might question it.


On the overpower/liability issue: While its not hard to believe that it would be low hanging fruit for a lawyer, I can't say that I've ever read or seen where someone was sued for such a thing. But forum after forum, and no matter what boat type, everyone, including myself, warns about the issue. If someone knows of any particular case or has links to info on that, would be of interest to me.
Project: 1995 1648 DMI/1998 25HP Merc:
1967 Starcraft 14' Mariner V/1987 Nissan 40C
1997 Bayliner Capri 2050/350 4brl Vortec Mercruiser
JohnS https://www.joefishin.com/

hkmp5s
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Who has the fastest tin??

Post by hkmp5s »

ETA: Reading is fundamental. I just realized you were posting the same basic question Fuzzygrub. I just woke up so I was a little slow. Anyway fuzzygrub I agree exactly whith what your saying. Wouldn't negative prop slip be nice. :mrgreen:


I think your getting some bad numbers by using a negative prop slip number. I don't know if that's even physicality possible.
You have your theoretical speed number, that is the fastest that that prop hill push your boat with zero prop slip. When you factor in any prop slip your speed number should go down unless they changed how math works.

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Derek
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Who has the fastest tin??

Post by Derek »

I believe that is fuzzy's point. :roll: Since a negative prop slip number is not possible, neither is 50 MPH

crkdltr
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Who has the fastest tin??

Post by crkdltr »

15 foot flat boat, 40 hp with 13 pitch prop, 6 gallons of gas, two batteries, trolling motor, tools and tackle I get up to 28 / 29 mph on gps with it trimmed out. With the trim down getting 26 mph.

Looking to change the pitch to a 15 and see if I can break into the 30's. :D

reedjj
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Who has the fastest tin??

Post by reedjj »

Crkdltr,

I would think you would be more around 35-40mph easy. I went from a 12 to a 14 pitch prop on my 1542 with 25hpmerc and didn't gain any more top end speed but it cruised much easier and got way better range out of 6 gallons.

How much weight do you have in decking and stuff? I had plywood floors, 6 gallons of gas, 2 batt, cooler and 2 adults and was running 31-32 in pretty much the same size boat with only the 25hp. Even in my new boat, a heavy welded G3 1756 with the 40yamaha 2 stroke Im getting 32mph.

I can only imagine what the 1542 would have done with the 40hp on it?

fastcajun
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Location: S Louisiana

Who has the fastest tin??

Post by fastcajun »

I agree with reedjj, it seems you should be in the 30s already. Do you know how many rpms you are turning at WOT?
2010 1644 Alweld tunnel runnin from a 93 Tohatsu Mega

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linehand
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Who has the fastest tin??

Post by linehand »

crkdltr wrote:15 foot flat boat, 40 hp with 13 pitch prop, 6 gallons of gas, two batteries, trolling motor, tools and tackle I get up to 28 / 29 mph on gps with it trimmed out. With the trim down getting 26 mph.

Looking to change the pitch to a 15 and see if I can break into the 30's. :D
Sweetness. It took me a couple trips to get the trim figured out on mine. And momentary switches...but I ended up with a 20 pitch Raker and it is working well. I would think a 40 could handle a 17 pitch if you have power trim....just a thought.
Family, Fish, Work, Repeat.

crkdltr
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Who has the fastest tin??

Post by crkdltr »

The boat is fairly heavy. The rear deck is made of aluminum, same thickness as the boat, carpeted, 3/4" marine plywood front deck and myself in the upper 200 pound range.

As of right now WOT RPM is about 5100 so it's pitched correctly with the max RPM being 5250. I'm waiting for the delivery of a Tiny Tach to make sure my RPM gauge is accurate.

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