Super Jet Anyone ever try a pump wedge on a SuperJet ?

[Boris]

When installing an X-metal trim on my trusty old SN I went ahead and welded a piece of aluminum to act as a stop on the bottom of my nozzle. Didn't want the cable to be under constant strain when the trim wasn't being used.
Anyway, I welded it on where the trim ring wouldn't sit at 0* but more like 2* or 3* up (bout what a pump wedge would be) thinking that I could always file it down to the final setting.
Is any of this making any sense ?

So, I threw the ski into the lake and took it for a spin and instantly noticed that it felt a lot more playful. As if the hull got shorter and lighter and wanted to change directions much quicker. Riding more nose high with less hull in the water would explain it all but here is where things get weird. The sucker turns so much better now.
I was dragging elbows at will without a hint of sliding out. That just goes against all norms and it should be quite the opposite but the sucker actually rails. WTF ?
Pulling a hand full of trim mid corner when the ski is laid over makes things very interesting.
Thrust vectoring is a blast.

Any input ?

 

[Waternut]

The kawi 750 used them to correct the angle of the pump so it's not unheard of. The 750 puts it down though.

 

[WaveDemon]

When installing an X-metal trim on my trusty old SN I went ahead and welded a piece of aluminum to act as a stop on the bottom of my nozzle. Didn't want the cable to be under constant strain when the trim wasn't being used.
Anyway, I welded it on where the trim ring wouldn't sit at 0* but more like 2* or 3* up (bout what a pump wedge would be) thinking that I could always file it down to the final setting.

I don't know why there would be any strain on the trim cable unless it's too short. The jet blast tries to make the trim/turn nozzle point straight back. That is why I've never understood why people put those silly springs on the bottom of their trim. The spring only works when you're using the trim on the trailer.

 

[Cannibal]

I don't know why there would be any strain on the trim cable unless it's too short. The jet blast tries to make the trim/turn nozzle point straight back. That is why I've never understood why people put those silly springs on the bottom of their trim. The spring only works when you're using the trim on the trailer.

X2. I never understood those springs. Keeps things tight while bouncing down the road though. No function when in the water.

Also, you can install those 750 wedges either direction can't you? Pretty sure, but they trim down to help with porpoising.

Would be kinda nice if someone made a wedge for a SJ.

 

[WaveDemon]

does the wedge go between the reduction nozzle and the stator? I've never seen one before.

 

[Boris]

does the wedge go between the reduction nozzle and the stator? I've never seen one before.

That's where they go.

I wanted the cable as tight as possible to get all the pull I could out of it.
Welding on a stop was easy and seamed like a logical step since I was welding up the siphon and visibility spout holes anyway. Now the cable has just a bit of slack when not in use.
How can that be bad ?

 

[WaveDemon]

That's where they go.

I wanted the cable as tight as possible to get all the pull I could out of it.
Welding on a stop was easy and seamed like a logical step since I was welding up the siphon and visibility spout holes anyway. Now the cable has just a bit of slack when not in use.
How can that be bad ?

Putting stress on a cable is bad, your solution sounds OK to me. I've just never thought about doing it that way before. Do you have a D-cut rideplate? What you are describing sounds like it would make sense with a d-cut plate because it would squat the rear making the d-cut bite more.

 

[Boris]

I have a deep d-cut.
Not as extreme as yours but deeper than most. I have a half sunken boat and a few hundred mangrove trees to thank for that mod.
I threw on a non-molested stock plate just to see what would happen. It did level things out a bit but still way different.

 

[Boris]

Anyway, I'm thinking about adding some spacers between the stop and trim ring to get a bit more angle. Just want to see what another degree or 2 will do for the handling and how far I can go before the thing starts porpoising like a mother.

 

[blaster800]

If you have an aluminum steering nozz you can weld the top pivot hole closed and redrill the pivot hole .. its just an option if you have aluminum ... I use this on my b-1 to angle up a lil bit for playing in the waves , I like it this way ... fwiw

 

[OCD Solutions]

My SE trim system has a built in stop and adjusting bolt for tuning the trim angle. I have mine up around 9° right now. It really lightens up the nose and makes the ski turn much easier.

I like the idea of the wedge and was thinking it would get me back some of the throw i lost but the trim ring still bottoms out in the same place on the reduction nozzle so it won't really net me any more.

 

[Big Kahuna]

I just adjust the cable at the lever for some positive static trim. Worked that way for years and I am on my original cable from 2006

 

[#ZERO]

You should drill & tap your welded bung fitting for a stainless 6mm bolt & nut to make it height adjustable.

You can also offset the steering nozzle holes for use with larger diameter bushings so the nozzle is pointed slightly upward and the trim ring is point more downward. This will make the nozzle more level when centered and rotate slightly upward on turns creating a similar effect without having the nozzle permanently aimed so high.

The reduction nozzle bore angles can also affect your nose pressure; the shallower nozzles use 1~2 degree angles which create more nose pressure while stepper 3~4 degree angles lighten the nose up.

 

[Boris]

That's some great input there #ZERO.

I like the steering nozzle idea and will have to look for some material for thicker bushings.

Didn't know that the few degrees would make such a huge impact on the handling. I used the only Raider reduction nozzle I had on this setup but I still have my SJ nozzle. Something tells me that I need to start work on a reduction nozzle 2.0 using the SJ one that will have an adjustable stop and maybe a few other bits and pieces.
Either way, I'm liking the wedge effect.

 

[JETSKIHORDER18]

I see that you guys are talking about wedges. I actually have designed pump wedges in solid works here at my college and was going to build a few, and try them out. Is this something that would interest you guys?

 

[garretonufer]

I was looking through ericmalone.com and saw that they have a pump wedge available that mounds between the wear ring portion and pump vein portion of the over all pump.

Just throwing it out there

 

[Proformance1]

I loved my Skat trim on my SXR for this reason, I trimmed up the nose and it would roll over on a dime. You could flat water stab by just truning the bars. I was just thinking of doing this on my SJ soon