Delta force performance-electics

[DISAR]

Hi all,

I am testing a Delta force, 36in. length, with a Feigao 9XL, 3s2p (11.1v,8000 mah), Venom 80a with props X445,X646,prather 220. The overall performance was better with 445 and best with 220. I tried also smaller props but a lot of cavitation and no speed. I know that for this boat the KB 45 is best, and got one from OSE (Thank You) but I want to test the 9XL first. What I noticed is that with the 646 the rpm was very low (12,000) comparing to 445(17,200) and to 220(18,900) but the amps were constant at 45 amps. What I want to ask is:

a) Why with the 646 the rpm dropped and amps constant? Is that because the 9XL does not have enough torque for this boat?
b) If i run the bats in series (22.2V, 4000 mah) the performance is gonna be better? With what prop?
c) If I use 2 Nimhs 14.4V 3900 mah how can I get the best out of it?

Each run was for a short time abt 1.5 mins and all temps (motor,esc,bats) were very low abt 80 F. I attach also the Eagle tree results. If anyone can help me and give some advise it will be perfect. Thank you.

[D. Newland]

I used to know how the 220 prop compared to the Octura's. I think it's similar to a 545? Anyway, the x646 is the biggest prop you have and that's why the rpm's are lower. Not sure why your amp load isn't higher, though, but your data indicates that the prop is too big for that setup.

Were you happy with the performance of the 220?? If so, stick with it. It doesn't seem like you're pushing your setup to a dangerous level.

The 9XL has been tested by many of us on 4S LiPo's or 12-14 cell NiMH's. That's where you'll get a lot of feedback re: setups (X442 to X445 prop-but that will get you very close to your ESC limits).

I haven't seen a 3S combo run in a bigger hull, but it sounds like you're somewhat satifisfied with what you're seeing, so that's good! If you go w/a 6S1P 4000 mah setup, you will need to prop way down (x438 or so). You will get much better performance, but higher amp loads and shorter runtime (assuming your hull will plane with that small of prop).

IMO-especially with your bigger hull, focus in on a 4S setup.

[DISAR]

I am not very happy with what I see. I also have a SV27 and I want to get similar speed with the Delta force. I will try the 4s or 12 cell NimHs,Thanks.

[Steven Vaccaro]

A 9xl is just not enough for that boat.

I'm not sure on why the amps did not raise, but have had a similar situation with a 10xl. At the time I was running 12cells and a 10xl. Many years ago I tried to run with the same exact boat, 10xl and only 6 cells. Surprisingly the boat was ok in speed. So I kept propping up to gain more speed. I got to a point where I could prop up and gain no more speed and no noticeable difference in runtime. This was before the days of the eagle tree. Not sure why it happened.

[DISAR]

Thanks Steven,

I will do a couple more tests with 4s or 12 cells and then try the KB 45.