Metal versus plastic prop instability

[Speedracer128]

Intresting... My neighbor has a Spartan and recently when I ordered myself a new prop I ordered him an x442 as well. Fine design recommended to run that prop with the Spartan. The x442 def has more lift than the stock prop but i thought it did add some speed to the boat. We are without a gps so you have much better data. Is your spartan a v1 or v2? I thought the v2 breaks 50 with stock set up on 6s.

I'm fairly new to FE boats but I have plenty of experience with power boats. I've owned 2 24 foot catamarans with twin outboards and when I was growing up my father raced offshore powerboats. Clearly I have a lot to learn with this hobby and I will read the above link discussing the different props. I am surprised that putting a metal prop shaved off some speed. But I am interested to learn how you tune this boat

[jetnfast]

I have the V2 hull. I am going to try another x442 that is slightly detongued and see if that helps. I have an x642 on order as well. I was able to hit 49.7 mph on the stock prop and stock motor which isn't bad at all, but I figure the no flex x442 should push it to at least 52 mph or so. I think it still requires some fine tuning of both the prop, trim tabs, and CG (Batt placement).

[jetnfast]

Back from more testing, this time with a different x442 prop. On this particular one, I really thinned it out and only slightly detongued the prop. I ran a best of 51.2 mph with the batteries just a little aft (toward the stern) of center. It was on nice calm water as well, which probably helped. There was a slight bit of chine at WOT so I could only hold it for about 5 seconds. Nonetheless, 50 mph has finally be broken with a stock motor and the x442 on my Spartan...now its time to get to work and finish my CF fighercat Daytona!

[Speedracer128]

How is your strut angled? And do you have your trim tabs adjusted?

[jetnfast]

neutral strut and almost neutral (slight 1mm down) on the tabs (4 of them). Seems to finally be dialed in.

[Speedracer128]

K. Thanks. We're still trying to dial in my friends spartan

[Jack6835]

Hi. Looks like I?m 8 years late. Lol! However wanted to chime in. After reading through all these posts I am speechless. I?m running a stock Spartan w stock prop and get speeds of 50-55 mph. I also have a M41 w a SeaKing 180a ESC and a TP Power water cooled CM 2350 KV running occurs X445 and getting speeds 70 +mph with no problem other than heat build up if you stay throttled on the stock Spartan. There are many more factors in the boat other than the prop? The lipos are key! I?m running maxAmps 6500 MAH 11.1 V in series. The strut angle and trim tabs in conjunction with the battery placement are where you get your speed/handling. The drive line alignment is critical too The biggest problem is heat buildup and the boat being too light for the power.

[KNUJ11]

Lipo's will never cause your electronics to heat up. They might actually prevent excessive heat if they are not capable enough and therefore deliver less power (=less heat).

[Speedracer128]

Lol. Yeah. That was a long time ago. I believe buddy is running different boats now

[Speedracer128]

Are these gps mph you speak of?