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No difference in Top Speed at WOT
Posted: Tue Aug 09, 2016 1:40 pm
by LOTW
I was just wondering what you guys thought about the fact that I got no difference in top speed at WOT with 14 adults on the boat vs 2 adults. Would this have any implications for prop selection?
2014 Crest Classic Tritoon - with Upper Deck
25' length
CP3 Package with lifting strakes
Full fuel tank (58 gallons)
Dual batteries at the back
Extra 20 gallons of fuel in containers
Upper Deck with additional loungers & storage
500lbs of gear / food & drinks for 14 people
200hp Merc Verado
14p Enertia Stainless Prop
32MPH @ 5900 RPM in both scenarios.
Front Bimini Top
Full Enclosure
You would think adding 1500 lbs of people would slow the boat down a bit?
Re: No difference in Top Speed at WOT
Posted: Tue Aug 09, 2016 2:36 pm
by Bamaman
Setting pontoon/titoons up sometimes works in mysterious ways.
Lightly loaded, 200 hp and a tritoon should see substantially higher top speed than 32 mph. Is your engine running optimally? Your Enertia 14 pitch prop should be close to the right prop for your application.
Maybe your engine's running too low on the transom and plowing.
Re: No difference in Top Speed at WOT
Posted: Tue Aug 09, 2016 3:42 pm
by teecro
That's not a Tri-Toon its a BARGE... 25 foot with upper deck and furniture...
Re: No difference in Top Speed at WOT
Posted: Thu Aug 11, 2016 3:32 am
by JerEazy
With the displacement type of hulls on the toons your speed is going to be limited. That and the drag from the deck etc.
I would say the engine you have is topped out for the most part on speed. so the weight isn't really having an effect. I would be curious about your fuel burn with the extra weight though.
Re: No difference in Top Speed at WOT
Posted: Wed Oct 12, 2016 11:54 am
by LOTW
Here is a picture under power at optimal trim and ~25mph. Does it look like it is plowing to you guys?
Re: No difference in Top Speed at WOT
Posted: Wed Oct 12, 2016 11:56 am
by LOTW
I should mention that at the end of the season when this picture was taken, I unloaded all the gear for storage, took off the enclosure fully and removed everything not bolted down. Top speed was actually slightly lower at 30MPH at 6200 RPM.
Re: No difference in Top Speed at WOT
Posted: Wed Oct 12, 2016 1:30 pm
by Bamaman
Sorry, but the plowing they're talking about is not at the rear--it's the front of the toons plowing thru the water.
Most tritoons with strakes and the engines trimmed up will have the water breaking 3-4' behind the back of the nosecone seamss. They essentially "fool" the hull into getting up on top of the water vs. displacing the water by plowing through it.
Are you trimming the engine as high as it can go without ventilation happening?
When throw the throttle to my boat when trimmed out, at about 30 mph I can feel the front end actually lift a few inches. My 40 mph speed comes from getting those nosecones out of the water.
Re: No difference in Top Speed at WOT
Posted: Wed Oct 12, 2016 2:11 pm
by LOTW
Well... I feel like an idiot for thinking it was at the rear! I've seen it mentioned that moving the motor up or down a few holes on the mount can help. I have the nose trimmed up as far as I can before the motor starts to ventilate (starts hitting the rev limiter at 6400 and speed slows down).
When stopped, the boat tends to sit quite heavy at the rear. I'm assuming this is due to the weight of the upper deck and slide which are at the back of the boat. It never feels like it's plowing at the front.
Re: No difference in Top Speed at WOT
Posted: Wed Oct 12, 2016 2:36 pm
by LOTW
I'm sure this likely won't help either, but on the off chance it does... This is the wake behind the boat.
Re: No difference in Top Speed at WOT
Posted: Wed Oct 12, 2016 2:46 pm
by jimbo21165
I've raced boats all my adult life.
There's NO getting around horsepower to weight ratio....
Re: No difference in Top Speed at WOT
Posted: Thu Oct 13, 2016 6:30 pm
by cwag911
How are you measuring your speed?
Re: No difference in Top Speed at WOT
Posted: Fri Oct 14, 2016 5:02 am
by BobL
[quote="LOTW"]I should mention that at the end of the season when this picture was taken, I unloaded all the gear for storage, took off the enclosure fully and removed everything not bolted down. Top speed was actually slightly lower at 30MPH at 6200 RPM.[/quote]
Do you slip your boat? This sounds exactly like growth on your toons.
Re: No difference in Top Speed at WOT
Posted: Fri Oct 14, 2016 5:36 am
by teecro
[quote="jimbo21165"]I've raced boats all my adult life.
There's NO getting around horsepower to weight ratio....[/quote]
Absolutely.... No man ever said "wish I'd got a smaller motor" as here is a boat actually doing quite well for its size, weight and HP... Want more speed? Should have selected a bigger motor as this rig is rated for 350 HP
Re: No difference in Top Speed at WOT
Posted: Fri Oct 14, 2016 7:13 am
by jimbo21165
[quote="teecro"][quote="jimbo21165"]I've raced boats all my adult life.
There's NO getting around horsepower to weight ratio....[/quote]
Absolutely.... No man ever said "wish I'd got a smaller motor" as here is a boat actually doing quite well for its size, weight and HP... Want more speed? Should have selected a bigger motor as this rig is rated for 350 HP[/quote]
I was actually pretty impressed with the 32 mph with that big of a 'toon, with just a 200!
Re: No difference in Top Speed at WOT
Posted: Tue Oct 18, 2016 10:01 am
by LOTW
I wish it was rated for a 350! Plate rating on it is only for a 200, so I got the max size I could. It's a 2014 model year. Seems like the upped the rating in subsequent years, although I'm not sure what they changed?