masterblaster
X-H2
Foam has little effect on rather it would back flow. The diff in height it would float would be minimal. The issue is the height of the waterbox and exh tube exit. When you move ski in water without it running
Freestyle new rrp carbon pipe
- Thread starter Jr Freestyle
- Start date
- Location
- Wasaga Beach
Harbor, I found this and thought it might help explain things.
http://scienceprimer.com/buoyancy
http://scienceprimer.com/buoyancy
speedysprocket
Alex
- Location
- Chesapeake, VA
When you put the life jacket on, you increase the volume of water being displaced, with almost negligible increase in mass.
When you add foam to your ski, you add a little mass, but because the foam is inside the hull, you don't change the volume displaced. To be analagous to your life jacket example, you'd have to strap your foam to the outside of the hull below the waterline, like sponsons that were hollow...
speedysprocket
Alex
- Location
- Chesapeake, VA
Phew, good! No more fluid dynamics lessons for today!^^^ Owe I get it put that way
What?
WILKEY
SO FAR CHANGE SUCKS!!!!!!
Lol
The foam isnt touching water its being added into the ski.. the ski will displace more water with the added weight of the foam.
Basic stuff here.
NVJAY775
My home away from home.
- Location
- Gardnerville, Nevada, United States
Yes. Bottom line is the foam adds a tad of weight to a solid sealed vessel. Hence it WILL sit lower in the water due to adding weight "foam". I has nothing to do with the density unfortunately. If you were to cut the bottom deck off of a ski and clean everything out of it. Stick in the water and draw the water line mark around it. Then do the same after ADDING foam it will sit lower in the water due to basic addition and subtraction. Something was added not subtracted. If the foam was helium impregnated, we'd really be onto something. Boyant or not. Weight is weight and if it's added, you're sitting lower in the water period. And there's different density foams as well as different foam materials. Which all have different strengths as well as different weight per cu ft.
Joker
...chaos? Its Fair!
- Location
- La Porte, Indiana
So density...
What you just said is essentially the definition of density.
Density has units of g/cm^3
NVJAY775
My home away from home.
- Location
- Gardnerville, Nevada, United States
So back to the water intrusion issue. On my hurricane the ex tube running through the hull goes through the bulkhead at the highest point possible and exits at the lowest point possible out the back of the hull. And it's a straight tube with no bends. No foam in the hull either. So the water has to climb up that before it gets to the water box. I normally launch and pull the ski with a bigfoot tote. When it's sitting in the water it's on a stand. This topic does worry me a bit, but I still haven't had any water intrusion.
Joker
...chaos? Its Fair!
- Location
- La Porte, Indiana
Why not set the hull in the water without the pipe in but the waterbox hooked up and see what happens?
masterblaster
X-H2
this is the real issue,you could have foam or not and it wouldnt make a diff,the inlet height of exh tube and water box height plumbing meeting it is the issue,id like to see pics of the hulls having this issue
NVJAY775
My home away from home.
- Location
- Gardnerville, Nevada, United States
Agreed. I feel for the guys having issues, because the pipe itself is amazing.
I've sat in my tray in 50' of water, filming and watching buddies ride with no issues. Or just floating next to the ski doing the same and still no issues.
I think you guys are right on the hull designs as far as ex tubes go? Def worth looking into.
I've sat in my tray in 50' of water, filming and watching buddies ride with no issues. Or just floating next to the ski doing the same and still no issues.
I think you guys are right on the hull designs as far as ex tubes go? Def worth looking into.
- Location
- sask, canada
Yup, I had issues with my Footrocket that had just a straight exhaust tube. In my Trixstar hulls I use an exhaust tube that has two mandrel bends just before the bulkhead so the water would have to climb about 6 inches to get into the exhaust and motor. Haven't had a single issue with either of my Trixstar hulls and I've left them sit in the water for extended periods, and have also had to swim them in to shore. I think the exhaust tube design in the hull plays a huge role with this issue.
masterblaster
X-H2
This type of small low waterbox is the contributing factor to why this is happening with hulls with low entering exh, I heard the first ver rrp waterbox was blowing apart? is the second ver much diff inside or did the first ver not have baffles as well? They look to be about the same height. I like the design of the Xscream wb the best,it looks much higher and creates a big angle in the exh tube exit. You dont hear much issue with the pfp wb having this happen either? Wonder why hiro designed it so short,there must be something to it,seems to really make good power with the pipe
@hink320 mandrel bent thru hull exhaust tube is great, these types of tube set ups would definitely help.....
The thru hull tube design may in part be a long term solution for us all with regard to water ingestion with any pipe/hull configuration
For me I have no control over the thru hull tube so I must adapt.
So far I've spoken with 4 with the issue, hulls are, Rickter evo fs2,
Hurricane, Vision, and not sure what hull @623pwr has....
4 report no issues so far, hulls are Hurricane, Circus, Rickter, not sure on the model, not sure what brand the 4th hull is
That's a few different hulls with the same issue. It would Seem the common denominator is the pipe and TINY water box.
So for me and what I've experienced and observed it now comes down to set up. Set up is the only thing I can really change as the hulls are already built..
What's been an eye opener for me has been being familiar with my hulls thru hull tube, "straight tube, fairly low out the back and pretty high thru the bulk head while still being a straight tube". Placing my fully assembled ski in the lake with full tank of gas, "5 gallons in my case" and letting the ski float and observe the outside lake water line as it raps around the hull, paying particular attention to the water box area and stinger area of the outside of the hull. Removing the hood and re-examining and trying to plot the water line and translated it to the hulls interior. Examining the stinger, water box inlet and outlets and the box exit tube to thru hull tube as the ski floats and plot the lakes water level within these parts. "Water basically seeks it's own level so with a straight thru hull tube and this RRP un-baffled water box, I assumed the water within the parts is at lake level while at rest". My symptoms are consistent with this as well, raising the noise of the ski while loading allows sitting water within the pipe to back flow into the engine.
I posted my % of submersion levels in a prior post within this thread and last weekend found my ski floating lower than first measured, I don't believe I accounted for the tanks fuel level during the measurements so my stinger and water box inlet and outlets was even lower than reported
I raised the box 2 inches, the stinger 2 inches, used 30 degree elbows and an RRP poll tube to connect the box to the thru hull tube. Ran two tanks thru it and re-examined the lakes water level in my exhaust. Now the water box inlets and outlets and stinger are above the lakes water level. That should help quite a bit but I may go higher and or do a P trap if the issue persists.
The simple solutions for me is to plot the water line and adjust stinger and box as needed and or do the P trap @623pwr and the @buzzard mentioned.
Interior of my water box, the new style
The thru hull tube design may in part be a long term solution for us all with regard to water ingestion with any pipe/hull configuration
For me I have no control over the thru hull tube so I must adapt.
So far I've spoken with 4 with the issue, hulls are, Rickter evo fs2,
Hurricane, Vision, and not sure what hull @623pwr has....
4 report no issues so far, hulls are Hurricane, Circus, Rickter, not sure on the model, not sure what brand the 4th hull is
That's a few different hulls with the same issue. It would Seem the common denominator is the pipe and TINY water box.
So for me and what I've experienced and observed it now comes down to set up. Set up is the only thing I can really change as the hulls are already built..
What's been an eye opener for me has been being familiar with my hulls thru hull tube, "straight tube, fairly low out the back and pretty high thru the bulk head while still being a straight tube". Placing my fully assembled ski in the lake with full tank of gas, "5 gallons in my case" and letting the ski float and observe the outside lake water line as it raps around the hull, paying particular attention to the water box area and stinger area of the outside of the hull. Removing the hood and re-examining and trying to plot the water line and translated it to the hulls interior. Examining the stinger, water box inlet and outlets and the box exit tube to thru hull tube as the ski floats and plot the lakes water level within these parts. "Water basically seeks it's own level so with a straight thru hull tube and this RRP un-baffled water box, I assumed the water within the parts is at lake level while at rest". My symptoms are consistent with this as well, raising the noise of the ski while loading allows sitting water within the pipe to back flow into the engine.
I posted my % of submersion levels in a prior post within this thread and last weekend found my ski floating lower than first measured, I don't believe I accounted for the tanks fuel level during the measurements so my stinger and water box inlet and outlets was even lower than reported
I raised the box 2 inches, the stinger 2 inches, used 30 degree elbows and an RRP poll tube to connect the box to the thru hull tube. Ran two tanks thru it and re-examined the lakes water level in my exhaust. Now the water box inlets and outlets and stinger are above the lakes water level. That should help quite a bit but I may go higher and or do a P trap if the issue persists.
The simple solutions for me is to plot the water line and adjust stinger and box as needed and or do the P trap @623pwr and the @buzzard mentioned.
Interior of my water box, the new style
Attachments
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- Location
- sask, canada
Sorry I thought we were just talking about lay down pipes having trouble with water intrusion. I only have experience with the PFP, not the RRP.
I cut the heck out of my hull, so it was my own monster.
I used to have it happen to my sxr too. I would sit on the boat, b.s.ing with my buddies out in deep water, after 10 minutes it would load up. If I didn't sit on the tray it would be good.
I didn't have a pipe bender and I'm cheap, so I didn't have one made. I was a bit concerned about the straight pipe, but I just rolled with it. I finally got my turd down to the lake and sure enough, go park the truck come back, motors loaded up. Brand new 1000 and its full of fn' water.
After that I bought some silicone turbo joints, did some test with the motor out of it at the landing. I think the p trap is a must for me, just my opinion. Forget the straight pipe, ideally you could do it inside the tray area then run a straight pipe. Its a lot easier to work on the boat with the straight pipe. I just made due with what I had, its been great ever since.
I must admidt, that RRP pipe hits pretty damn nice!! I'm still a beginner, so not sure if that's saying much.
I used to have it happen to my sxr too. I would sit on the boat, b.s.ing with my buddies out in deep water, after 10 minutes it would load up. If I didn't sit on the tray it would be good.
I didn't have a pipe bender and I'm cheap, so I didn't have one made. I was a bit concerned about the straight pipe, but I just rolled with it. I finally got my turd down to the lake and sure enough, go park the truck come back, motors loaded up. Brand new 1000 and its full of fn' water.
After that I bought some silicone turbo joints, did some test with the motor out of it at the landing. I think the p trap is a must for me, just my opinion. Forget the straight pipe, ideally you could do it inside the tray area then run a straight pipe. Its a lot easier to work on the boat with the straight pipe. I just made due with what I had, its been great ever since.
I must admidt, that RRP pipe hits pretty damn nice!! I'm still a beginner, so not sure if that's saying much.
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