Water pickup drag testing

[Mxkid261]

Yes I did.

Does it help pull more water in like that?

[kfxguy]

Did you carve out that tear drop shape in the hull in front of the water pickup?

Yes I did.

[Mxkid261]

Did you carve out that tear drop shape in the hull in front of the water pickup?

[kfxguy]

Dam Travis, that Zelos looks so sweet with that green and the graphics applied.

Thanks! I'm loving it!


I know I've kinda veered off a little from just the testing by talking about pumps and stuff. Seems like there was a little interest in that too so I'll post my findings on that. I ordered a few different pumps and have tested two so far. I posted results on the the sensidyne and now I got one of those pumps from China. It looked very promising and it wasn't too big. The sensidyne pump is hard to attach hose to. This one isn't. The results were very poor.


11 oz in 2 min 2 sec on 2s
1 min 41 sec 3s
1 minute 22 seconds On 4s. Sad. Lol. I did not get hot on 4s though.

[Tamelesstgr]

Dam Travis, that Zelos looks so sweet with that green and the graphics applied.

[kfxguy]

So anything new from a Sunday run Travis ?

I didn't get to the lake today, it was raining. I did run the shocker yesterday too. First time running it on 8s since I crashed it. Ran very well even tho I had a longer rudder on it.

[srislash]

Went did test number one. Definitely did not turn out how I expected. I can't say this is a end all for this question however. Let me say why. First is I was not in contolled laboratory conditions. I made one pass and checked speed. Then I put hatch tape starting behind the step of the middle sponson to the end of the rear sponson. I would say that pretty much eliminated the pickup drag. Also because I was having a slight amounts of
of porpoising I moved the batts up one inch. Because it lost speed when I blocked off the pickups I ran once more with the batteries moved back to the original position. Speed was the same on this run also so I had to rule that out. All three passes were less than 1mph apart. So on to the videos. Here's video one with pickups.

https://youtu.be/0GppLp4RZqo

And here's run number 2

https://youtu.be/a9li7Tpdb0k

Here's how I blocked them off.

So anything new from a Sunday run Travis ?

[grsboats]

Dmitry you re right and this is a custom knife blade laser cut I did 3 years ago...since that only air water pick ups on my saw boats..and yes in hot set ups you will be surprised with the speed's improvement.

[dmitry100]

Grsboats: Where do you get your knife blades from? They should be wedge knives though right...

Grsboats is right on that one, replacing rudder blades with a thin knife one can give up to 5mph increase in speed for big SAW cats.

[grsboats]

Travis these water pick ups definitevely won't produce measured drag in your experiment but a knife blade rudder will....the speed on my SAW Jae with 4082 2000kv motor on 6S jumped from 85mph to 88mph just swaping the rudder blade.

[kfxguy]

Is your receiver upside down? Nice runs!

No, why?

[Keagan-Z06]

Is your receiver upside down? Nice runs!

[kfxguy]

Went did test number one. Definitely did not turn out how I expected. I can't say this is a end all for this question however. Let me say why. First is I was not in contolled laboratory conditions. I made one pass and checked speed. Then I put hatch tape starting behind the step of the middle sponson to the end of the rear sponson. I would say that pretty much eliminated the pickup drag. Also because I was having a slight amount of porpoising I moved the batts up one inch. Because it lost speed when I blocked off the pickups I ran once more with the batteries moved back to the original position. Speed was the same on this run also so I had to rule that out. All three passes were less than 1mph apart. So on to the videos. Here's video one with pickups.

https://youtu.be/0GppLp4RZqo

And here's run number 2

https://youtu.be/a9li7Tpdb0k

Here's how I blocked them off.

[kfxguy]

Update. I got the boat for the first test painted and reassembled. I also got one of the pumps in today. Testing Saturday.








This pump is very small but for its size it does very well. It is self priming too. It will shoot a stream about 5-6ft. I also timed it on three different voltages. I used 11oz of water and pumped into another cup.
2s took 1 minute and 23 seconds
3s took 1 minute and 6 seconds
4s took 58 seconds. It did not run warm on 2s or 3s but did run warm on 4s. The extra 8 seconds it dropped off isn't worth it. This is a sensidyne pump btw.



4s

[kfxguy]

WOW what paint and color is that?

And yes I am curious about the results.

Randy that's createx pearl lime green. It has an awesome pearl effect to it. It's water based so you can wash it off if you mess up. You have to wait a day or two (I usually give it two days) before you clear it so the clear won't lift. Check this one out. In the sun. Sold this boat tho. Miss it to.