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Head Janitor
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Discussion Starter #1 (Edited)
Ok...here's the deal. I'm still a jet-idiot (above all, the shoe is still the part that confuses me the most). I'm spinning a "B" impeller at 5700 rpm, and honestly with some more timing I have another 150-300 rpm left in it. Anyway, in my 21' Liberator with 4 people and full cooler (total passenger weight was 700-750 including me and the cooler was 40-50 lbs) I saw 60-65 mph at 5700 rpm. Maybe that's the "right" speed for my boat, I honestly don't know.
So...I'm asking for input both on what *should* my boat run with that load, and if it should be faster...how do I get there? I will add more horsepower in the future...but for now, lets assume a best case scenario of a "B" impeller at 5800-6000 rpm.

Here's a pic of my nozzle setup and ride plate, it's a 3-4* up angle.



Here's the underside:



 

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Head Janitor
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Discussion Starter #4
There is a allot of good info in here http://www.performanceboats.com/jet-boats/9068-21-daytona-splash-thread.html

You are gonna need to pick up a digital angle finder to get a base line and go from there.Tons of good info on here, you just gotta take your time and search for it.

Good Luck:)devil
I will look there, thanks. And I do have an angle finder. Using the keel as "flat", the ride plate has a 3-4* up angle now.


By chance, did you check the top speed with all the folks and ice chest out?
No, I didn't. I was just so happy the boat was behaving that I just flat forgot.
 

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Head Janitor
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Discussion Starter #5 (Edited)
Is there anything I can read that will explain the shoe to me? I've been told I need a back cut shoe, and that I have a tapered shoe. Honestly, that really doesn't mean anything to me (well, I think I grasp the concept, but what I *thought* was the shoe looks to be made onto the intake?)

Also, when measuring how far my loader sits above/below the keel, do I use the flat part of the keel or the bubble just in front of the loader?


For the mouth opening, do I measure from the front of the intake all the way to the rear-most part of the shoe? How do I change the mouth opening if it's too big/small?


Also...how good are the chances that my rudder is slowing me down?


Can you guys tell I'm a lost pup?
 

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Those look like stainless loader bolts, I dont think those are quite strong enough for a loader fastener...
 

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Head Janitor
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Discussion Starter #7
Those look like stainless loader bolts, I dont think those are quite strong enough for a loader fastener...

Oddly enough I was made aware of that just a few hours ago - I will check tonight...
 

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no need 2 fake it.
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definitely not a strong enough bolt.... TRG had some good insight for me, as i recently started paying attention to my loader... I pull it out the night before every river trip now. Now, Thanks to Todd, earlier in the day i'll go and buy four brand new grade 8 loader bolts, even if the old ones are still okay and not showing any rust... that way if you ever run short of time one day you have a stockpile of bolts ready to go in.
 

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no need 2 fake it.
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Oddly enough I was made aware of that just a few hours ago - I will check tonight...

also, i would get away from the phillips head screw type head, i would go with an allen head deal.
 

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Discussion Starter #10
I checked those screws. They are 5/16" SS with nuts on the topside. Do I still need Gr 8 stuff? If so, I'll have to order it because the local hardware store doesn't have them.


Also, from the rear most part of the shoe to the front of the "horizontal" part of the loader is 12.1"

The "horizontal" part of the loader is 5/8" because the keel that's just on the other side of the intake.
 

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no need 2 fake it.
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peice of mind, yes. i would definitely run grade 8... order a box of them and just rotate them out periodically
 

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Is there anything I can read that will explain the shoe to me? I've been told I need a back cut shoe, and that I have a tapered shoe. Honestly, that really doesn't mean anything to me (well, I think I grasp the concept, but what I *thought* was the shoe looks to be made onto the intake?)
go here. 4th picture down shows the difference between a tapered shoe and a backcut shoe. and yes, your shoe has a lot of taper.

http://home.pacbell.net/jmcclure/ShoePlate.html
 

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21 Daytona
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5,291 Posts
Is there anything I can read that will explain the shoe to me? I've been told I need a back cut shoe, and that I have a tapered shoe. Honestly, that really doesn't mean anything to me (well, I think I grasp the concept, but what I *thought* was the shoe looks to be made onto the intake?)

Also, when measuring how far my loader sits above/below the keel, do I use the flat part of the keel or the bubble just in front of the loader?


For the mouth opening, do I measure from the front of the intake all the way to the rear-most part of the shoe? How do I change the mouth opening if it's too big/small?


Also...how good are the chances that my rudder is slowing me down?


Can you guys tell I'm a lost pup?
rudder is probably slowing you down a few MPH, a 4 degree wedge raising the droop up
will probably help a little.
 
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