TP 4050 1950kv on 6s

[Mxkid261]

mmmmmm... crispy esc.... I was going to suggest maybe upping the esc and it wouldn't hurt to invest in something to log with while experimenting with props, just to know where you stand.

Oh I know the limits of that setup haha. I haven’t had any “fast” boats out in a couple years. Been on a small boat/low voltage kick.

[R2315]

Sorry, that was directed at the OP since he will be testing things out. I use the Seaking 180a in my 4s setup and although it's been great I still log everything when testing a new setup or prop.

[kfxguy]

Let’s get a couple things out the way. First off, why do you feel like you need to limit yourself to 30k rpm? That was a longtime “old” rule that most people went by a few years back. You really needn’t worry with that anymore. Especially if your running a quality motor like a tp or neu. The 4060 would be a good choice and I sent a few boats out with a 1860kv 4060 that ran on 6s. They never failed. Seaking 180 esc in the boats, they were 80mph cats that were stone reliable. A built a few like that and none failed to this day that I know of and that was a couple years ago. 40k rpm really isn’t dangerous any longer. The way motors are made now the rotors don’t fling apart like they used to.

Second, why are you limiting yourself to old school props? Sure octura are good props but abc is a much better prop. If you want a comparable prop to an x642 then you need an abc 1615-17-45 or a 43mm would be a 1715-17-45. I’ll give you an example of what your leaving on the table. A 1815-17-45 abc is the substitute I use for a m645 octura, I’ve seen a 10-12mph increase with the abc and it pulled the same amps in that particular boat. Trust me when I tell you that abc is a faster choice. You will need to angle your strut down a touch with the abc because it will want to raise the bow and push the transom down.

[T.S.Davis]

That was a longtime “old” rule that most people went by a few years back.

Back to this nonsense again. The P sport world record was set at right around 30000rpm last fall. At the same event I set the Q mono record with less than 30k also. Q was since bested. Not sure what rpm that was though. You tend to discount what guys setting records do as "old" school. Never going to understand it. Lower rpm with a more prop is more efficient. This isn't speculation. We have the proof in the record books.

The ABC props are killer but can't be had. The 1815-17-45 works on a bunch of things. Trouble is, you can only get ABC's from custom prop machinist and only in limited sizes. I've been waiting on props for so long I don't even remember what they were that I asked for. Needed them for Atlanta. Not gonna happen.

[kfxguy]

Back to this nonsense again. The P sport world record was set at right around 30000rpm last fall. At the same event I set the Q mono record with less than 30k also. Q was since bested. Not sure what rpm that was though. You tend to discount what guys setting records do as "old" school. Never going to understand it. Lower rpm with a more prop is more efficient. This isn't speculation. We have the proof in the record books.

The ABC props are killer but can't be had. The 1815-17-45 works on a bunch of things. Trouble is, you can only get ABC's from custom prop machinist and only in limited sizes. I've been waiting on props for so long I don't even remember what they were that I asked for. Needed them for Atlanta. Not gonna happen.

No offense meant. Seems like you took it as such but that’s not how I meant it. The quality of motors has improved since the more experienced guys (is that better than old school? :) starts doing this.

Now, not thinking that I really needed to clarify precisely every little detail....but hey this is the internet and people will point things out in a heartbeat.....yes things can be done at a lower rpm but you have to consider several things:
-can this new guy do that?
-is it really better to pull the kind of amps that it would pull turning an aggressive prop?
-does he have the speed control that can handle that?
-does he know how to dial in the hull to be as efficient as possible?
-does he have the money to experiment when he burns stuff up figiguring it all out?
-does he have rules he needs to follow?
-is he trying to set a record or just have fun?

Considering those questions, common sense tells me the easier and less costly way of doing what’s he’s trying to do would be with a little more rpm, less prop and higher voltage. All of which usually equals less amp draw and less burnet escs if your not an experienced boater.

[CraigP]

It’s interesting, because we have the 3 camps of RC boats, each with different objectives on this one thread. Travis is a sport boater interested in max straightaway speeds and doesn’t race. I’m a sport boater and interested in running in oval, with emphasis on turning, no race. Terry is a full blooded racer, and a good one at that! I think we each need to understand where the other is coming from. Racers tell me that they wouldn’t even have a boat if they couldn’t feel the thrill of competition. But there are no racing events anywhere near where I live, so why would I want to go to 1-3 events a year and get my butt kicked? I like doing an emulation on the 2-lap record thing, and I have a stop watch. Travis likes to build boats to get the most out of them. Since they are insanely fast, his world is max rpm’s. I respect that very much. Not my interest, but realize it’s not an easy thing to hit 100mph on a 30” boat! You racers amaze me. I don’t think I have the reflexes to navigate a race with other boats out there! I respect the fact that you guys put your boats in harms way every time you compete. But that would just freak me out! Way too much work in it to see somebody drive over the top of hit, or how I would feel sawing some other guy’s boat in half.

Thru all of this, there are setups that best fit these different camps. So I think it’s the OP’s responsibility to declare what the intention is, so we as a group, can offer better advice. At least that’s the way I see it....

[kfxguy]

Thanks Craig. Well put. You are a good mediator lol.

For the record, I’m no longer just about zip zip anymore. I have some other stuff I’ll run around the lake just to play with but I don’t really post much about them.

I don’t have to reflexes or coordination for racing however lol.

[T.S.Davis]

No offense meant. Seems like you took it as such but that’s not how I meant it. The quality of motors has improved since the more experienced guys (is that better than old school? :) starts doing this.

Fair, I know you weren't trying to be a weeny. In our old guy thinking defense though.....the Q motor we set that record with 1 month old TP. So not exactly old technology. Better motors? Yes and no. Seems less expensive motors have gotten better. Lehner hasn't changed their design in eons. Guys are still laying down some ridiculous numbers with those. Same with Neu. Same design. Guys have gotten better at harnessing what's available. More impressive has been the cell chemistry changes. Even crappy cells are better than what we had just 5 years ago.

Now I'll put on my old guy experienced, been there, burnt that up hat. I've done the 60000rpm dance. It's much more expensive to experiment at high rpm. When things go wrong it's instantaneous. It's much more likely with less experience too. Something as simple as the gap too small at the drive dog can result in a baked esc. With a high torque lower rpm setup a mistake might make a little heat.

By all means guys, don't forget to have fun. No other reason to do any of this crap. It is however, less fun when you're equipment is baked. The risk is higher with higher rpm setups.

[T.S.Davis]

so why would I want to go to 1-3 events a year and get my butt kicked? I.

OMG Craig, because it's ridiculously fun. Wish I could some how bottle it and send it to people. We would have so many racers. The people too. I've made so many friends over the years. RC boaters, despite the way it reads on line some times are the finest people you ever could hang out with.

For the longest time I was getting to actually race once or twice a year. I was terrible. We had to host a race to get one of them. Dark times. hahaha

[CraigP]

I agree with you Terry, but I can't let my enthusiasm slack off because I can't race. Tulsa used to have 2-3 RC boating clubs, all fuel/gas clubs, I believe. But the ponds got pinched off to them for noise and pollution concerns. So now there is none. Even Oklahoma City is down to one... I would have to be able to run a couple of times of month at least to get my driving skills to be where they need to be. I'm just not wired to show up somewhere and hang my underwear out! It's a fault, but I am what I am... I know I'm missing out on some good, potential, deeper friendships too..

But I really wish the racing community would drop this low voltage, high current nonsense and use a voltage that yields lower current levels. I really don't want to consume my attention with my boats, trying to figure out mitigations for high current issues. I've been an engineer too long and know that you just end up losing at times, because high current is just trouble. There's so much up side to using less amps for the same power configuration. You don't need the most expensive of everything to make it work and compete. Cheaper batteries with higher IR values can be used, because your only using 125A instead of 220. Esc's are certainly cheaper... Motors are very expensive to wind them so they are fast AND can mitigate the heat rise caused by large amp flows.

So I'm left with proving to myself, that these setups are a blast to work with! I play my own games, I got a radar gun guy now that reads the entrance and exit speeds of the boat, working on optimizing turning speeds. I got a course that's pretty spot on to 1/6 mi. My boat has zero pollution concerns, thanks to FE and the sealed struts I'm using. So it's about lap times, building nice boats, and keeping them number side up! I just don't want to get all down and out about not having an RC club close by..

You know, I am involved in other racing endeavors. Mainly, I build BBC (Dart block) blown alcohol motors for my brother's GP boat, the GP-55. So I save my competitive spirit for that. I get to 3-4 races a year in his class. If you want some excitement, go to a GP race sometime and hear those blown boats hitting 180mph on the longer courses, just puts the hair up on ya! But I would like to just come out to an event at meet all you guys, and shoot the s--t, if you know what I mean!

[kfxguy]

Fair, I know you weren't trying to be a weeny. In our old guy thinking defense though.....the Q motor we set that record with 1 month old TP. So not exactly old technology. Better motors? Yes and no. Seems less expensive motors have gotten better. Lehner hasn't changed their design in eons. Guys are still laying down some ridiculous numbers with those. Same with Neu. Same design. Guys have gotten better at harnessing what's available. More impressive has been the cell chemistry changes. Even crappy cells are better than what we had just 5 years ago.

Now I'll put on my old guy experienced, been there, burnt that up hat. I've done the 60000rpm dance. It's much more expensive to experiment at high rpm. When things go wrong it's instantaneous. It's much more likely with less experience too. Something as simple as the gap too small at the drive dog can result in a baked esc. With a high torque lower rpm setup a mistake might make a little heat.

By all means guys, don't forget to have fun. No other reason to do any of this crap. It is however, less fun when you're equipment is baked. The risk is higher with higher rpm setups.

Yea I guess I was referring to about 40k rpm, definitely not 50-60+k rpm. I think 40ish is a safe rpm for the most part. If course you’ll likely have less problems at 30k but you’ll have less speed, which is less speed and a new guy may not know how to access more speed without the extra rpm. I’m currently trying to dial in a heavy mono with a less than ideal motor with a low rpm. It’s not very easy to be honest. But until I reach my goal on the lower rpm I’m turning, I refuse to throw more battery at it.

[CraigP]

I too have had difficulty getting bigger props at slower speeds to work on my setups. I just start picking up prop torque problems, and realize that I would need a different mind set on how I go about setting up the boat. I'm just not a big fan of hull asymmetrics, such as offset prop shafts, offset weight loading (although I will use this) and radical sponson asymmetrics to make it work really good. I want my boats to run flat and neutral. Maybe not the fastest, but I keep my consistency better and the boats tend to stay number side up better.

[danzuby]

Technically it's a 36" cat but it's the Traxxas M41, they call it 39" but if you measure from the transom to the very front of the bow it's 36". I'm not dead set on any motor yet but pretty sure I'm going with TP and 4050 1700kv is where my head is at right now so I don't have to change out the ESC. The stock traxxas motor is a 3684 1800kv turning the X642, I'm not planning on propping up too much, I thought about just staying with the X642 and doing the 4050 1950kv, and my other thought was the 1700 turning the X645. Many here saying that I need to be in the 50mm range for a cat this size but the bottom line is I need to stick with the 180amp esc for now so I don't want to dump too much more cash into a cheap Traxxas boat. I would have never started with the M41 but it was new in the box with batteries and charger for $350. I've upgraded everything that one can possibly do in the boat except the motor and that's not gonna happen til the stock motor craps out.

[Mxkid261]

I don't want to dump too much more cash into a cheap Traxxas boat.

Ignoring others suggestions when I first came around here, I put a bunch of money into a spartan (my first boat) like 4 years ago. It ended up going airborne around 55 mph and ripped the entire top half of the hull apart from the bottom half, and went to the bottom (luckily in shallow water). That being said, I wouldn't put anymore money into an almost 40" plastic boat, but that's because of my past experience.

[dmitry100]

Roaring Top lipo's were used to go 180mph .... https://www.youtube.com/watch?v=GRxEuTfIqso

So I think that would mean they are probably pretty good.