Super Jet hooker 9/15 or 10/16?

[Pro-pulsion]

Is there any comparisons between standard hub and big hub designs? I have a Hooker 9/15 but also a Skat 14/18 standard hub and have never run it. I have often wondered which theory would be more appropriate...big hub reduces pump volume, but produces great pressure, small hub has lower pressure, but carries more volume. I don't believe I have ever seen any comparison testing between the two. Impros has a small write up about the two but don't actually state and pros and cons between the two.

 

[kevbo]

Flow is not restricted by a 75mm hub. There is no work being done at the hub so making it larger keeps water and air from flowing backwards at the root of the blades. Large hubs prime faster and make more thrust as low hull speeds. That is why they seem so much better to us. Large hub impellers do nothing for speed in smooth water, a 25year old straight pitch will go just as fast.

 

[Pro-pulsion]

That's a great description kevbo, I didn't think about right at the hub center actually. It makes total sense to utilize the area making the most of the rpms, the hub center is going to have the slowest rotational speed by comparison to the mid point and beyond. I probably should have elaborated on my thoughts a bit more as well, I was thinking more along the lines of efficiency rather than a top speed vs top speed or holsehot vs. holeshot. I was thinking more along the lines of transfer comparisons and any other efficiency differences. Other thoughts could be volume cavitation potential comparisons, flow volume rate measurements, dead zone turbulent spots. What I mean by that is when considering aircraft wings, the tips generate a dead zone in regards to positive or negative effect on lift or control, but that dead zone also creates a vortex of turbulent air flying away from the wing tips. Since the principles of aerodynamics are identical to hydrodynamics, would the longer blade surface throw out turbulence at the blade tip creating cavitation whereas the large hub has significantly reduced cavitation. I love scientistic type things like this...yes I said scientisitc, it's a Duck Dynasty Si thing lol. This is a great topic though, thanks to the OP for posting the original question, it has been an area of great interest to me

 

[Half flip95]

60mph? From a limited? With a 9/15?
That's insane! Post up your specs, I want that!

 

[Big Kahuna]

60mph? From a limited? With a 9/15?
That's insane! Post up your specs, I want that!

Not gonna get 60 on a limited. Tricky use to run full stroker flat top motor, total loss Type 9 pipe, mag pump and wad hard pressed to hit 60-61. Also Mag Pumps not allowed in a limited class ski, at least they did not use to be.

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[Half flip95]

Lol I know, I was being a smartazz as usual.

 

[37]

Also Mag Pumps not allowed in a limited class ski, at least they did not use to be.

They have been for a while. It's part of the formula that killed limited class being affordable.

11.6.1 Impeller housing, stator vane assembly, pump mounting plate and/or pump shoe may be modified or aftermarket.​

 

[Mike R]

I know this is an old thread....But I have a stock '94 SJ and '95 Blaster that could use new impellers and am in research mode.
Just talked with Impros today. They recommend the 10/16 over the 9/15? I was surprised and they said that is what they are currently recommending for stock up through limited setups.
Anyone have some recent experience running with either. An earlier poster with a limited SJ preferred the 9/15 over the 10/16.
Thanks for the opinions.

 

[Big Kahuna]

Same response in your other thread. 10/16 would be a best overall prop. the 9/15 will give more down low but you will run out too soon for any good top speed.

 

[East623]

I’ve ran both before. To be completely honest it all depends on what kind of riding you’re doing. If you like to carve and get up to speed then roll with the 10/16 but if you’re only jumping then the 9/15 is the way to go. My current freeride superjet is going to be running a 10/16 in a Solas mag pump unless I feel like swapping it to a 9/15 for some reason but I doubt it.

 

[Half flip95]

Not gonna get 60 on a limited. Tricky use to run full stroker flat top motor, total loss Type 9 pipe, mag pump and wad hard pressed to hit 60-61. Also Mag Pumps not allowed in a limited class ski, at least they did not use to be.

Sent from my SAMSUNG-SM-G930A using Tapatalk

did he ever try a half stroker?

there are a few tuners out there that can get a limited superjet to go 58 and a limited SXR to go 60, but don't expect the engines to last long.

for the rest of us 55ish is the best we will ever see on a limited legal ski but it hardly matters because the class doesn't exist anymore.

letting the hydro run aftermarket parts hurt limited class. letting the two strokes use fancy pumps was a failed attempt at keeping parody in the class. then the ijsba killed the class this year to have another modified high dollar class


I have a nearly new hooker 9/15 for sale. 250 shipped