MC Handling question.

[floatn turd]

Trying to "dial-in" my MC would a 'longer' and or 'wider' rudder help this turd in any way? Or is it all COG and strut angle?

[xlandguy]

Sounds like you don't like your MC too much. I don't know if it's dumb luck or a miracle. Or could be my total lack of knowing how a boat should run, but mine, on first real run yesterday impressed the H out of me. Fast, stable, smooth, no fear of flipping I had a blast once I got the bugs worked out. More runs today. I did sharpen my rudder on leading edge and bottom, stock prop. Today may try the Grim Racer 445 I have, but its not balanced. I dont have a balancer yet.

[floatn turd]

I like it, but mine has a lot of weight to it, cause I "foamed" it and run 8s. So its a heavy boat. Its has a ton of torque. I have to 'roll on' the throttle it just jumps out of the water onto its side, so its hard to get it to run just right in the corners.

But make sure yr prop nut is on real tight, we have all lost a ton of props to the murky deep.

[mtbenjamin77]

I don't think that boat likes alot weight. My buddy has one setup with 4082 1600kv on 6S and it runs like it's dragging an anchor for a few seconds then you give the rudder a side to side blip and it lets loose. But we can't seem to get it to really top out. Radar says around 48 won't even break 50. My SV27 runs 53 all day on the same radar. It's running a x445 and the batts are all the way back with 0 pitch and 0 lift in the strut. The extra weight does seem to make it flip over in the corners at lower speeds. I couldn't imagine this hull on 8S.

[pavmentsurfer]

My best guess would be that my stock MC with only a (non balanced or sharpened) grim 42X55 prop is running 40-42mph on 4S NO mods. Im interested to read that the heavier the boat gets the harder it is to keep it performing well. I have a NEU 1515 1Y motor here (39X69, 2200kv) I was thinking about trying in it... still on 4S but id gain the extra KV... but maybe ill hold off and leave the boat alone. It works soooo good for me just how it is. Turns sharp, lifts the nose and runs really dry but still corners excellent.

[xlandguy]

Runs dry. Does that mean with less rooster tail? or what exactly?

[pavmentsurfer]

It means less of the hull in the water... heres a visual example:


Boat is almost entirely out of the water. Its fast this way, but it can get very "loose" and is basically right on the edge of blowing over. Still, when the hull lets go of the water the speeds noticeably increases.

[Brushless55]

Would changing the strut height make any difference?

[floatn turd]

I don't have a GPS, but mine does 'haul', I cant give it full throttle for more than a sec or 2, cause it will start to 'get sloppy' the airborne.
I'm just not sure if its not "dialed in" or is that I have just "maxed out" that hull as far as speed and handling goes? Cause everything has a point where it just cant handle anymore.

So here is what it does: At full throttle the A** end of the boat starts hopping around, when I start to loose control it always starts from the back.
here is what I have tried: 0 strut angle, batts fwd and back
+ strut angle, batts fwd and back
- strut angle, batts fwd and back
I have tried every combo using the strut all the 'down' and all the 'up' with the all combos of batts position. So thats what brought me to the rudder. Maybe a longer one will keep the rear of the boat from hopping around. Or maybe thats just the way it is with that kind of power and weight.

I just don't know.

what do you guys think??

[floatn turd]

My best guess would be that my stock MC with only a (non balanced or sharpened) grim 42X55 prop is running 40-42mph on 4S NO mods. Im interested to read that the heavier the boat gets the harder it is to keep it performing well. I have a NEU 1515 1Y motor here (39X69, 2200kv) I was thinking about trying in it... still on 4S but id gain the extra KV... but maybe ill hold off and leave the boat alone. It works soooo good for me just how it is. Turns sharp, lifts the nose and runs really dry but still corners excellent.

Mine take also flips in the corners at lower speeds, I think your right. and it is the extra weight. O well "it is what it is".
As far as leaving it alone (stock)....i think i wish i would have done that. Its fun to watch it "eat up" the lake but its not fun to drive. I bought an apparition as a 'rescue' boat, now that thing is fun as hell to drive. Its fast and stable at any speed. I don't even want to mess with it. But anyway I would just leave it 'stock' if I could go back in time..

[xlandguy]

Maybe the boats weight distribution is messed up due to the foaming? Did the hull warp? My MC is very stable. I ran a couple of sets of batts through it last night and it was stable as can be. I don't think I could flip this thing if I tried! I was running a sharpened rudder, and Grim's 42-55 metal prop, unbalanced

[siberianhusky]

If you can't flip it you aren't even close to it's potential top speed. Even with the stock motor and esc!
FT Try an airdam to keep it from packing so much air into the center section, a piece of windshield wiper may be enough.

[xlandguy]

I never even heard of an "air dam" as relates to RC boating, would you explain please? Also, one of the reasons I picked this boat for my first is that I read many reviews, one of which really stuck with me. The boat is doing almost 40mph, box stock and even the reviewer said this boat was nearly impossible to flip. What is the speed this should run with stock motor and 4s? Mine seems very fast, but I am totaly new to RC boats.
LINK to review

[mtbenjamin77]

I have an idea for my friends MC. I'm going to try putting an air dam in the tunnel underneath the boat. I know this does well for some sport hydros. I think it'll help the hull break loose from the water and not drag so much on acceleration and then at high speeds it should reduce lift to keep the sponsons in the water and increase control. Anyone ever tried some thing like this? I'm gonna give it a shot this weekend and let you guys know how it works.

[mtbenjamin77]

If you can't flip it you aren't even close to it's potential top speed. Even with the stock motor and esc!
FT Try an airdam to keep it from packing so much air into the center section, a piece of windshield wiper may be enough.

Great minds think alike!!! LOL

[siberianhusky]

It's not needed at all on a stock setup.

[floatn turd]

If you can't flip it you aren't even close to it's potential top speed. Even with the stock motor and esc!
FT Try an airdam to keep it from packing so much air into the center section, a piece of windshield wiper may be enough.

I will give it a shot. So attach it to the bottom and how far back from the "front" of the boat would you put it? or right at the front?

Thanks

Mt.T

[siberianhusky]

I'd try as close to the front as possible, some 2 sided tape should work. Never tried it on a Crew, one of the things I'm trying on my SAW cat next time out.

[xlandguy]

So who's gonna tell me about this air dam? What is it? What does it do?

[floatn turd]

So who's gonna tell me about this air dam? What is it? What does it do?

Like a "wing" on the back of a nascar or other race car, but this if for the bottom of the boat. Its to keep a little less air from going under the boat @ high speed and keeps it from lifting.

[pavmentsurfer]

My MC will flip at WOT if even a slight gust of wind hits it. It wont flip if its calm but it does get pretty squirrely if its choppy. It hops around a bit at the back but it NEVER looses control completely. Its a super fun boat to drive this way. I know its right on the edge and I've saved it from going right over at the LAST second more than once. I can see how more power would certainly put this thing on its lid no problem. But the way I've got mine setup, its every bit as fast as i want it to be but still stays on the ground... as long as those rogue gusts of wind don't get me at the wrong time.

[xlandguy]

I'm going to have to get a video of mine running. Either it's super slow or I got lucky as heck on my setup cause mine seems glued to the water. If someone with some knowledge could evaluate it, that would be very helpful.
Also, did you sharpen your rudder? I have, leading edge and bottom.

[pavmentsurfer]

I havent sharpened my stock rudder but I have an SV27 rudder with the built in water intake to put on it and I'm going to sharpen that one before i install it.