Flow Guards efficiency in surf?

I thought the whole idea of the flowguard, was to eliminate the chance of thrust entering the exhaust creating a bog in the motor??


Okay, so spoke with a couple peeps last night about this and it does help with what has been said through this thread and others but the real reason for it is for the back pressure in the pump. Okay watch this video if you haven't....

http://www.youtube.com/watch?v=qTPOtXXbel8

Towards the end he fills the lower gap with putty/clay and then resin is poured in between the flowguard and reduction nozzle. Once it is dry you can remove the flowguard and the resin makes a perfect cast to fit exactly onto your reduction nozzle. So once it is installed there is no way for water to escape between the flowguard and reduction nozzle. Okay so why this helps....when you hit the throttle and the pump is pushing the water through it and out the reduction nozzle and then through the turn nozzle there for sure is pressure going backwards off of the turn nozzle and it would go between the reduction nozzle and where the flowguard is, that being said, once the flowguard is installed PROPERLY, there is no way for the water to escape between the ruduction and flowguard, thus making it go out the normal turn nozzle flow. I work with farming pumps and I just know that 'our' reduction nozzles aren't big enough to allow ALL the water to go out, especially with the engines we are using now days, there is definately back pressure in the pump escaping and this is what this was built for. Again it also helps with ther problems that have been talked about already but this is really where all the gain comes from.

Back pressure ohh grass hoppers :)
 
Location
dfw
Yea I had no idea!

Some shops are using a flexible plastic, metal, and/or rubber extension on the fixed nozzle to seal the gap at full throw. This is a cheap and easy way to do it with existing parts. A better way would be to use a Kawasaki ZXI style steer nozzle with its hemispherical bucket and a rigid bulb attached to the fixed. This would provide a fully articulated seal.
 
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227

Its all about the surf!
Location
Oceanside, CA
Some shops are using a flexible plastic, metal, and/or rubber extension on the fixed nozzle to seal the gap at full throw.

This seems to be the best idea yet, at least for surf riders. In the Flow Guard install vid, I noticed that the Rickter nozel already had some sort of rubber extention on it. Do you have a link for a shop that sells something like this?

For the poor mans route, The B pipe coupler is a good idea also!
 
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Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
Some OEM Yamaha trim rings have rubber extensions on them that are longer on the sides to prevent water from getting out.
 

Watty

Random Performance
Location
Australia
Before I do a search (I'm lazy) Do you know what model? Are they a bolt on swap with a SJ?

I just replaced a trim ring a turn nozzle on a customers GP1200, it had the rubber extension on the trim ring you speak of. I didn't check but I'm 99% sure these will fit up to our trim systems.
 
Location
Oregon
gp800 & waveraider 760 both have the rubber spacer and trim ring here is a chart that may help with fit applications. i'm pretty sure that most stock redution nozzles that have trim have that rubber spacer as well.
 

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if you look closly in the the vid you can see the rrp flow guard doesnt extend far enough back to do much with the steering nozzle,they use the gp800 trim ring with the rubber built in for that purpose,the main thing its doing is keeping the pressure loss behind the trim ring from moving backwards into the pump,thats why they are filling it with epoxy,their whole reduction nozzle setup fixes a few issues,I was looking at it closely on roks ski at world finals,they deff had a few tricks up their sleeve. He was getting more flat spin rotation than anyone else by a large margin
 
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