Is this fast for 4s?

[kfxguy]

Nice work Travis! Isn't it funny that with many things, sometimes when we aren't really trying or don't really care, we get the outcome we wanted!?!?!?

While I've never built a boat to your standard and $$$, I have crashed a few and it always stinks.
It is an awesome day though after running 2-3 of my boats and everything makes it back home safely!

I know. The cool thing about this boat is I can run it on 3s for 78-80mph fun and it's stable as could be or I can run it on 2s all day and have 50mph fun and probably never flip it. To add to it, I could put a longer rudder on it and it'll turn although it doesn't do bad on 2s. Prop down a little on 2s and it may go even faster, I don't think the motor really cares for 2s, seems a little weak so less prop may help. Fun little boat it's turning out to be although it ticked me off for a few weeks lol

[dmitry100]

So... what is the limiting factors at this point with this Rivercat and the Shocker in terms of speed? You probably aren't at the point of maxing out the ESC right...

Have you tried going up a lot higher in pitch while trimming the diameter a bit ?

[kfxguy]

So... what is the limiting factors at this point with this Rivercat and the Shocker in terms of speed? You probably aren't at the point of maxing out the ESC right...

Have you tried going up a lot higher in pitch while trimming the diameter a bit ?

Well the shocker I haven't gone up in prop yet. Using a very conservative prop, all I have for now. Once I finish the repairs to it I may have the next step up in pitch which on the Rivercat was worth 2-3mph but the shocker motor has more power than the Rivercat, so it may be worth more. The Rivercat is about as fast as I want to go at this point. Really I was only looking for 95mph on 4s. I've passed that so I think I'm going to back it down and change esc's. I like the castle no doubt, but the throttle response it has is too much. I can jump the Rivercat out the water at will. The sf300 in the shocker doesn't do that. It's more controlled and much softer hit. I need that in the Rivercat more than the shocker. I still have an alien 300 I may try. The major thing that's stopping me from running a sf300 in he Rivercat is the fact that a sf300 will only go down to 4s and I still want to be able to run it on 2s and 3s. Being able to tweak the speed on 2s without fear of flipping was a major help. On 3s it gets a little rowdy but on 4s it's pretty silly. I don't want that much power all the time. I do have a mgm 25035 that I might try but it's just as responsive as the castle but noticeably smoother.

I'm not going to cut down any abc props, they all have some extra cup towards the tips and that would be going backwards getting rid of that. Besides, there's just about any pitch and diameter I might need without modification. There's a couple new numbers that will be out very soon that will expand the selection even more. I'm afraid to mess with any of my props as they already perform pretty good as is, I'm just s/b-ing them.

[kfxguy]

And no, the esc isn't close to being maxed out on the shocker. The Rivercat is pulling more amps but it can handle a little more. I'm sure the strut position isn't perfect yet but I'm afraid to change anything lol.

[Mxkid261]

Jeez that thing is movin! Is that two 4s batteries in series?

[kfxguy]

Jeez that thing is movin! Is that two 4s batteries in series?

It's two 5000mah 4s packs in parallel for lots of run time. It'll do the same thing with one battery in it. I like the extra capacity.

[Mxkid261]

Wow thats fast as hell for 4s thats crazy. What size motor is that?

[Lone-Wolf]

Where is your CG at for these runs roughly?

[kfxguy]

Where is your CG at for these runs roughly?

It's around 9" from the rear of the sponson

[Lone-Wolf]

Interesting, I would have thought you would have needed it much further forward to keep it on the water, maybe I don't need to rip out my esc mounts in the sponsons of my EKOS to stuff the batteries in there...thanks for the info! Keep up the great work...and threads

[kfxguy]

Interesting, I would have thought you would have needed it much further forward to keep it on the water, maybe I don't need to rip out my esc mounts in the sponsons of my EKOS to stuff the batteries in there...thanks for the info! Keep up the great work...and threads

Well here's the thing. You really can't go by my cg because I have weight (in epoxy) added in the bow and transom. If you have reliable flotation I'll tell you what you need to do. Let me know.

[Lone-Wolf]

Just back from running and finally got me EKOS to 60mph on 3S with 36mm 3-blade CNC's...happy with that as it's more of a budget build...but how you can manage those number in such small boats astounds me! I'll PM you...and thanks for offering to help.

[kfxguy]

Just back from running and finally got me EKOS to 60mph on 3S with 36mm 3-blade CNC's...happy with that as it's more of a budget build...but how you can manage those number in such small boats astounds me! I'll PM you...and thanks for offering to help.

Running it at almost 98mph is setup on full kill. It's not a sport setup. If your not careful the boat will jump clean out the water. Now 3s is not bad at all. It runs 78-81 (depending on conditions) on 3s and it doesn't really flip. On 2s it runs close to 50 but I think it would go faster with less prop. I don't think I'm going to run it this weekend although I probably should. It was nice out today and tomorrow it's supposed to be nice and around 72f. If the wind isn't blowing I may go make some runs.

[kfxguy]

Little update. Harry over at Speedmaster made some new longer rudders like what I'm using on this thing. I can't say "I" was the whole reason for making these rudders but I was a part of it lol. They are about 1/4" longer that his regular small rudders. Believe it or not, a 1/4" could make or break the stability of the boat. What ive found anyway. I have a prop with a bit more pitch than what I ran 98 with and it should pick up (we know how that goes sometimes lol) but I know it's not going to stay on the water. I have a feeling that with 1/4" more rudder in the water it may be just enough to help keep it down. I'd much rather change a prop and a rudder that to have to fool with the strut after getting it to run so well. I might slow it down lol



Here's one of the nice billet rudders.

[buckt1]

Kfxguy . I love reading all your posts. Man, you are like the king of speed ! You are the reason I bought a rivercat hull, now just gotta go read all your stuff again to figure out how to build it. you have forgot more than I will ever know but trying to learn. I see a lot more floatation in your boats now, stuff like that saves us newbies from learning the hard way. Keep up the awesome reports