Hull weight to HP?

[Redbelly]

I have a tunnel hull 16' x 54" bottom. The hull weighs in at 900lbs. It has a 3/16" bottom and 1/8" sides.

Is my 40hp slow on hole shot due to weight or prop? The boat is rated for a 60hp. WOT she runs about 28mph, according to a gps.(with 2 fatboys)
It is a 4 stroke motor.

I have the rpm gauge and plan to have it installed by this weekend for a report on that figure, too look into a 4 blade prop. But am I wasting time? Should I look for more HP?

[Will_Fish_4_Food]

That sounds about right to me for what you described. Sounds like you need more horsepower, or less fatboys to me

[Barhopr]

Take this with a grain of salt but I don't think you'll see a significant gain in speed to justify the cost of a repower to 60 horses. I know it's not the same boat but, I have talked to folks with my same hull but with a 40 and some with a 50. We all have within a mph or 3 of each other and for the most part the same prop. We never measure the hole shot times and distances but I'm pretty sure the extra Hp. helps. I think the extra horses of my 60 helps maintain a higher speed when loaded heavy that the 40's and 50's wont. .02

[Redbelly]

That makes sense. I'm not looking for more top ens speed. Perhaps a 4 blade prop will do the hole shot thing I want. I'll know soon. The other agonizing thing is to increase hp I have to significantly increase transom weight.
Top end w/2 fatboys and ice chest and two tackle shops at 28 mph I can live with, but will be losing some of that with a 4 blade. Maybe TC's prop man can set me up!

I'll be getting some rpm figures this weekend or before.

[Hit-n-Miss]

Put a stingray jr. hydrofoil on it. You will plane out in half the time /distance or less. I have one on my 25 nissan on my k16 Sundance and I jump on plane with 1 or 4 people in my boat. It will stay on plane at lower speeds too. Speed is 21-24mph no matter the load. It will be the best $50 you ever spent.

[CairoTrout]

Had a 50 hp stay with my 70 hp today and not much diffrence in weight in the hulls. He was probablay like Barhopr said 3-5MPH slower than mine.

[grim reeler]

My 18' seaarc tunnel hull will do 31mph with a 50hp and my buddies 19' duracraft does 33mph with a 90hp. I talked to a guy that had the standard hull version of my boat with 60hp that would run high 30's.

[CATCH 22]

I have a tunnel hull 16' x 54" bottom. The hull weighs in at 900lbs.

That seems like alot for a 16. You might want to check your floatation, might be water logged. If not, my suggestion would be Trim Tabs, they'll get you outta the hole alot faster by helping with displacement at the transom. By the way I design/build Alum. boats very simular to the Scandy White

[Redbelly]

I called Scandy White and they told me the weight. Add to that the motor, jack plate, trim and tilt, full gas tank 12 gall., me...230lbs , tackle bag 50 lbs..... then the ice chest........