Is 40 too much to ask for???

[tiqueman]

So, I swapped my esc and motor from my BJ26 into my Imex 32" cat. Mainly because Ive got the Imex handling INCREDIBLY well and the BJ even if I threw $100 at it, from what Im seeing, it still isnt great.

Ive been playing w/ strut angle and height along w/ c.o.g. in this 32 and so far Im only getting my butt kicked. Started out with getting a gps installed. Ran it down to the pond the first time and hit 37.7mph. This was on 4s 5000mah 20C Reedy, on a sharpened and balanced 642. Then I started adjusting. Up, down, angling, more, less, and only scrubbed speed off. Anything to do w/ raising slowed it down. Lowereing introduced some wild handling characteristics, ie bouncing or chine walking. It ran its best ride attitude and ran like it was glued to the water with the strut at the location I got the 37.7 with, but angle up a bit more. That adjustment however dropped me to 36.8. After slowing it down to 35.2, Ive only got it back up to 37.5. I just cant break that 38 and I WANT 40MPH!!!!! Temps are as follows: ESC 108, MOTOR 110, batts 125.

Any recommendations??? I was thinking maybe a 3 blade? I know Octura makes a 440 3 blade, but with that Im losing pitch, as well as diameter, but Im thinking the pitch will hurt me the most? Isnt the general rule of thumb when going to a 3 blade, reduce the diameter by 10% but keep the same pitch?

[tiqueman]

Ooops... too MUCH to ask for. How do I edit the title???

[Diegoboy]

I corrected it for you.

[tiqueman]

Thank you!

[Gerwin Brommer]

What are the rpm/V for that motor ? ( as an European I don't know the Black jack motors)

[Boatman]

around 1500kv. that prop just wont get you there. try a plastic 45mm. You should see low 40's with a loose setup.

[tiqueman]

When you say a "loose set up", you mean run it high?

What about the Prather 220 I think it is, or a Octura 1740/3

[Boatman]

Good point. Prather has a prop around 43mm with a ton of pitch. That should yield higher speeds and less amp draw. I mean have the boat just short of blowing over. Run times with larger props will be shorter for heat and amp draw but to gain the speed with that setup it is really your only choice. I havent had any luck with 3 bladers on cats YET. On hydro's they can work great.

[tiqueman]

What about going to a 5s set up? I just have to add an external BEC correct? And if I go to a 5S, everything needs to be the same ratings, ie mah, "C" rating, but what about brand?

And if I do that, do I stay w/ a 642 or do I have to prop up or down?

[Gerwin Brommer]

1500 Kv on 4S ????????????
Waaaaaaaaaaaaaaaaay to low rpm !!!

[Brushless55]

1500 Kv on 4S ????????????
Waaaaaaaaaaaaaaaaay to low rpm !!!

That's stooooooock!

[Boatman]

What about going to a 5s set up? I just have to add an external BEC correct? And if I go to a 5S, everything needs to be the same ratings, ie mah, "C" rating, but what about brand?

And if I do that, do I stay w/ a 642 or do I have to prop up or down?

you are correct on adding BEC. That would be a wise choice. You amp draw on average should decrease with keeping a 642 rather than going 4S on a 45mm prop. I would keep you mah rating and C rating as high as possible for both weight and runtime. I have seen blackjack motor on 6S although proboat esc was not used on that run it was a blast.

[tiqueman]

1500 Kv on 4S ????????????
Waaaaaaaaaaaaaaaaay to low rpm !!!

Yes, this is the Proboat BJ26 stock set up... nothing unusual there.

So I took a chance and did it. Oh man, I should probably be slapped by all FE boaters, but I got my 40 and didnt blow anything up. And Im going to remember that and not do something like this again until I have all the proper things. I took my Reedy 2s 5000mah 20c and paired it with a unknown brand 3s 4500.. who knows what "C" rating and no, I didnt have an external bec. I ran 3 short laps and went 40.2mph

[Jesse J]

I love those motors. With a proper esc they can go on 6S! My 27" cat flies on 5S and is out of control on 6S - closer to 50mph.

[tiqueman]

Yeah Im thinking thats next, a different ESC. But even at high 30's on 4s, It is a blast and gets most of the people out of their houses along the pond to come out and check things out. Seems at times, like this afternoon, I spend more time talking to people about it and answering questions than I do running it.