Waterboxes

Hey, any of you guys tried different waterboxes in your B1? I don't mean the typical alluminium boxes that replace the stock glass box.
Particulary interested if anyone has tried a rear mount GP760/ GP800 waterbox with a highly modified big block engine.
Need the flow with the motor we're running, still need the back pressure & need it to still be quiet.
Thanks
 
Yes - run the GP760 box. Do NOT modify the inner baffle.
This is the box ran in the top pro boats in the SJ era. the Blaster 2 box is similar with different entrance/exit places. I have both but cant remember, (They are burried in teh attic)
 
Thanks for the info, that's actually good news that the GP 760 box handles a stroked big block without having to mod the box.
I've got a GP 760 & a GP 800 waterbox that I've sat in the rear of the hull (the top deck is not glued to the hull yet).
The GP 800 box is a bit on the big size for the hull & makes the horse shoe shaped rubber hose not sit well.
The GP 760 box sits in much better & the horse shoe pipe bends nicely in the area under the seat.
I want to make mounts in the hull for the waterbox before I bond the hull & topdeck together, so needed to decide which box was best.
Did anyone ever make an aftermarket waterbox in the shape of the GP 760, if so was it as good as the stock box? Just thinking about availability.
 
No nothing beats that box for 800-900cc in a Yamaha. (GP760 box) Most Pro Seadoo Factory boats in the mod era used the same box. There are a few other Yamaha boxes of the same era with the same size holes. WB2 and a couple of other models.
Another real good box is a SXR box (850cc) Aftermarkets SUCK in my opinion. Not enough back pressure for the model it fits. Some people love to run gutted boxes and small stingers I just dont like that for Skis or Blasters. GPR's its ok....if you racing GPR's.

Now most of what I say above is for closed course racing not freestyle with lower RPM
 
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The waterbox is going into 3 surf blasters I'm building, 760cc, 780cc & a 910cc billet ADA.
All 3 motors are crankcase & cylinder ported, ADA heads, total loss prog. ignition, factory B mod pipes, twin 44 super bn, 46 bn & 48 novi's, etc, etc.
You mentioned that the box setup you described was for closed circuit, I'm hoping the the GP 760 box will be fine for the lower reving surf conditions?
 
The waterbox is going into 3 surf blasters I'm building, 760cc, 780cc & a 910cc billet ADA.
All 3 motors are crankcase & cylinder ported, ADA heads, total loss prog. ignition, factory B mod pipes, twin 44 super bn, 46 bn & 48 novi's, etc, etc.
You mentioned that the box setup you described was for closed circuit, I'm hoping the the GP 760 box will be fine for the lower reving surf conditions?

It won't be any issue at all.
 
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