80+ mph 32" rivercat

[kfxguy]

I'm creating this thread to document my progress along with getting insight from you guys. I build this boat originally to just go fast. As fast as I could. My first time out wasn't very encouraging. It was fast. Super fast. But I wasn't ready for it yet. I'll admit, I'm still a newb in this having only a year into it. Yes I can build. Build very nice, but now I'm starting to put it to use. I didn't have a place to run very often so I didn't get much time on the water. Then I found a great big Ole lake a half mile from me. Now I can test, test and test.

I decided after the maiden voyage of my rivercat, it was a hand full. More so than I had experience. (You won't see people admit that very often). So I put the thing on the shelf for a while and messed with building mostly. Learned alot. Mainly from you guys, and I truly appreciate it. Some of you guys have helped me greatly. I made up my mind after the flip it did for no apparent reason, I was gonna back I down a notch. Play with it for a while. This is one sweet boat. Love it and don't think I could part with it. I put a 1520 1500kv motor in it. It was fast yes, but I didn't like it. Mainly I didn't like it because it wasn't tuned in. Over the next couple weeks I got to get a bunch of runtime under my belt. Figured some things out. Got my mini running very good and got the rivercat running Nicely. I changed to a 1800kv 1518 and I like it much better. Now for the good stuff!

First time out with the 1518, x642 prop 6s (all runs are 6s) t180 esc



Lowered strut to 1/8" below sponsons (no other changes)

[kfxguy]

Swapped to a m445 prop I prepared (I do all my own props)



Today: I did a m545 prop but first I made a backup run of yesterday with fresh batteries

M445 prop again (fresh batts)

[kfxguy]

Now I have set a goal for myself. I want 80 out of it. I know, I know...10 more mph might be hard, but I can try.

Here's the m545...batts were pulled down some from previous runs...need to try fresh ones next time.



I'm ordering a couple more props. My temps are low. I forgot my temp gun but the esc is barely warm and motor is maybe 105-110 if I had to guess. It's got more in it....

Here's a video

[robbo1]

When you say the 1500kv "wasn't tuned in" what do you actually mean? Did you ever get a GPS reading with the 1500kv and with what prop?

[keithbradley]

Now I have set a goal for myself. I want 80 out of it. I know, I know...10 more mph might be hard, but I can try.

That's definitely doable with that hull. When you get to 80, keep going. You might find yourself far exceeding your own expectations.

[kfxguy]

When you say the 1500kv "wasn't tuned in" what do you actually mean? Did you ever get a GPS reading with the 1500kv and with what prop?

I didn't have the strut adjust correctly. Plus it kept moving and that wasn't noticed till I go rid of the motor. I might should have kept it but I'd I find myself needing to go down in kv, I'll try a tp power motor. I just got a pair of them the other day and they are nice motors.

[kfxguy]

That's definitely doable with that hull. When you get to 80, keep going. You might find yourself far exceeding your own expectations.

Well I know, especially after reading that old thread of howards....with the 32" boat he used to hit 100mph using a leopard 4082. I refuse to let this thread go in the direction that one did tho lol.

Question: will a t180 work on 7s or 6s is it? I know it's rated at 6s only but you know how it is trying to push things. The built in bec went out today so I added an external one. I have some more props on the way and a couple other little hair splitting tricks up my sleeve. As it is right now I can hand it over to my 10 year old and let him drive it. Stay tuned, I have another back it up pass uploading to youtube. Be posted shortly.

[srislash]

We had a thread last year with someone running 8s on a T180. Never did catch what ended up happening. He claimed many runs.

[kfxguy]

Here's another video for your entertainment

[kfxguy]

We had a thread last year with someone running 8s on a T180. Never did catch what ended up happening. He claimed many runs.

Hmmmm...

[urbs00007]

you might want to try putting a little positive angle in the strut. get that nose up a little. did that with my daytona 37 single 4082. saw daylight under hull. you are running stuck to the water. after angling my strut, the hull would bounce at lower speeds, then stop at full speed. you arent going to get max speed out of any boat until you fly off the water, then trim it to stay on .

[Fluid]

I got mine up to 89 mph (through timing traps, not GPS) with a Castle 1515/1Y and a Prather 235 on 6S1P. I then ran out of motor (saturated the windings), so loading it more just added heat, no rpm. The boat was stable and could easily have gone faster, but I moved on to other boats. A small boat like this needs pretty smooth water to go fast, as light ripple will slow it down several mph. And yes, until you start blowing it off you are not loose enough! A strong build is important (motor mount, packs, etc.).

DSC00007.jpg



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[kfxguy]

I like it not blowing off the water lol. I think with the upcoming prop changes its going to have a little more lift anyway. I built her strong Jay.....epoxy in tips and tunnel. The sponsons have been leveled on the inside with epoxy. Jb weld on the motor mount. The transom has carbon plate and 1/4 thick epoxy built up. Whole front is filled with kintec two part foam. Carbon fiber down the sides and inlay. She kinda heavy but strong. I made efforts to keep extra weight low in the hull as possible. I have 6 sealed ball bearings in the strut. Balanced collet. I have not shortened the rudder yet tho....

[devo]

Im getting 70mph with a tacon 4074 2150kv in the same boat but mine is fiberglass. You should loosen it up to the point of no return and then install a piece of 90 degree plastic under it all the way at the way in the front. This makes the low pressure center move all the way to the front and keeps the boat planted to the water even when you loosen it up with the strut. I now run mine at 70 all the time and rarely have any takeoffs

[kfxguy]

Im getting 70mph with a tacon 4074 2150kv in the same boat but mine is fiberglass. You should loosen it up to the point of no return and then install a piece of 90 degree plastic under it all the way at the way in the front. This makes the low pressure center move all the way to the front and keeps the boat planted to the water even when you loosen it up with the strut. I now run mine at 70 all the time and rarely have any takeoffs

Thanks for the tips! Im just starting out with it so im pretty stoked ive gotten this speed out of it so quickly. Shes go alot more left in her for sure, I think anyway. The prop im running isnt anything specail and as most everyone knows, prop is everything. I expect to have a few more mph picked up by this coming weekend. Im going to loosi=en it up when that and only that is left for me to do. I was considering running it on 7s and not to mention the batteries i have arent the greatest either. A better set of batteries would likely pick me up a tad too. Like i said, ive just begun...... :)

[iridebikes247]

Better batteries helped a lot I noticed a substantial gain in rpm switching from zippy 40c batteries to dinogy 65c.

Etti makes a very solid 150a/300 esc capable of 7s if you're worried about it. 80 is a good goal but I think you'll get more eventually. Have you ever considered cutting down larger props? This is what I usually do in twin cats im sure this isn't too different. You can definitely run 7s to that motor I think that + some more prop tuning will get you to your goal and then some, just keep an eye on temps!

[kfxguy]

Better batteries helped a lot I noticed a substantial gain in rpm switching from zippy 40c batteries to dinogy 65c.

Etti makes a very solid 150a/300 esc capable of 7s if you're worried about it. 80 is a good goal but I think you'll get more eventually. Have you ever considered cutting down larger props? This is what I usually do in twin cats im sure this isn't too different. You can definitely run 7s to that motor I think that + some more prop tuning will get you to your goal and then some, just keep an eye on temps!

Good to know. I was thinking about switching to 65c spc batts. i could cut down props, I may give that a try also. At this point, I have so much more I can do I know i can surpass my goal.

[kfxguy]

Tried the sea king 180 on 7s and it won't arm. O well. Now I need another esc. I'm thinking mamba xl2, epoxy coated, remove circuit board from case and make a custom high capacity cooling block then heat shrink it.

[Spartanator]

Should try to find a used ESC on EBay or something... I past up a great deal on accident one day...

Oh, Sorry about the eCheck thing earlier.... Still mad at myself for that one. lol, someone here said they use the SK180 on 7s but hadn't smoked...

[kfxguy]

Should try to find a used ESC on EBay or something... I past up a great deal on accident one day...

Oh, Sorry about the eCheck thing earlier.... Still mad at myself for that one. lol, someone here said they use the SK180 on 7s but hadn't smoked...

Well my seaking 180 won't even power up on 7s. It beeps once and that's it. Unplug the 4s pack and plug in a 3s and it works fine.

[iridebikes247]

i got 12 mph going from a 447 to a 457 red to 50. gives an idea of what cut down props can do. higher rpm and pitch will be the answer as you know.

[keithbradley]

i got 12 mph going from a 447 to a 457 red to 50. gives an idea of what cut down props can do. higher rpm and pitch will be the answer as you know.

Keep in mind that while cutting props down might work well in a twin, that doesn't necessarily mean that it will in a single. Twins can run smaller diameter because they have twice the thrust. Small diameter props on a single drive boat can lead to drivability issues and excessive slip.

[kfxguy]

I have a Prather 225 and 230 on the way. I just need a higher voltage capable esc

[iridebikes247]

yup, i was thinking the twin vs single prop choice might be a bit different for SAW setups.

when i say cut down i mean cut down a bigger 4-series octura to a similar diameter prop that hes running. When you have the headroom its fun to play with setups, given Jay gave exact information for his SAW setup with the same boat I think the prather with the same rpm might be your ticket, he has the experience with the SAW singles.

[iridebikes247]

As far as escs go my friend ran the etti 150 with a 1527 neu a few years ago, a very hard setup and he had a good experience with it.

[kfxguy]

As far as escs go my friend ran the etti 150 with a 1527 neu a few years ago, a very hard setup and he had a good experience with it.

I looked at that esc but I wasn't sure if it would hold up. The mamba xl2 is out. Not going to fit. The only way it will fit is if I machine a custom low profile billet case. I'm not doing all that work to use an iffy esc. I think the Prather props will pick me up a tad especially since I can thin them a little more than the Octura props.

I think ose is out of the etti...any other place to get one?

[flraptor07]

Did you get the Bronze or the Stainless Prathers?

[kfxguy]

Did you get the Bronze or the Stainless Prathers?

Stainless

[kfxguy]

Found an etti 150 esc. Hopefully get it by next weekend. Now on to splitting hairs while I wait on other stuff. Here's my plans so far:

-Ceramic motor bearings
-Ceramic roller strut bearings (I already have the strut roller as it is. I have 6 sealed bearings in it and it seems to be holding up fine. I've never run this boat without the roller bearings so they do have a little use on them. I have regular steel bearings in it just as an experiment.
-higher mah and c rating batteries (I have 5000mah 50c, going to 6500mah 65c)
-better prop, checking on having a Custom one done.
-new esc
-7s up from 6s
Those few things should pick me up

(Hair splitting lol)

[MarkF]

kfxguy

If you want to go fast try the abc line of props. Maybe a 1816 for starters.

Mark