brc51

Thanks for information and will do just as you said, but i do that to the nitro cars ive had When even new but you did tell me the pitfalls i was hoping to hear about and i thought about changing radio as soon as i unboxed it and saw it. It looked like a toy one.Since your all veteran boaters i always like to ask.

wave waker

ur welcome,,,i agree with u about the toy radio and it's a smart move to ask....keep posting of ur boat progress...btw, mentioning about veteran boater, there's only one veteran and senior boater here in RCU and no other than RON OLSON, peace Ron....i learned a lot from that guy.

brc51

Well i hope to glean alot from you guys and learn as im new the only boats i had before was a kyosho ep 750 jetstream and an auqua force air boat that i bought used and it barely ran,and yesterday i shipped the kyosho to a wheelchair bound man so his son could have a boat simular to his dads so they could run together.It was a freebie but i also like to share the hobby with others.

JPriami

My Feedback: (21)

The boat got on plane no problem after I did that to get the strut deeper in the water. Last time I run it the boat was planning on just the rear hull steps. the rest of the boat was skimming the water like a hydro. I havent run the boat since doing all the paint work. I was going to go today but rain got me. Hope to run tomorrow. I sanded the bottom of the hull lightly too so it should help against the hull sticking to the water like I had read. I bought a aeromarine sprint cat & OPS 67 so that will be my next project. I'll leave the TC31 with the stock motor for now. I polished the carb all the way though & build the custom larger diameter header for the dynamite anyways and it runs good for what it is. I would like to get a rudder with a water pickup built in it though.

wave waker

ok got V24 rudder and temporarily installed, also silent tuned pipe and low profile radiobox, hopefully this set-up will work..

Hesco Racing

I could be wrong but I see a steel bolt in both mountings of your rudder. If so you wont get the nockout effect of the rudder. Replace bottom with brass screw. They sheer off nicely.

JPriami

My Feedback: (21)

Let us know how that one works out wave. looks neat. btw where are those speed reports?

wave waker

progress done today, mounted servo holder, not really good lookin' and all are crooked, as long as functional that's fine for me..

i'm hopin by tonight radiobox is done and ready for tomorrow test run,,,i'l get the speed tom. hopefully.

HescoR, yup, i'l need to replace the stock rudder bolt.

wave waker

boat tested today, everything seems work during few laps of 1st tank until throttle servo got stock wide open[X(], at first felt kinda panic, i can't stop the boat, either i'l flip it or wait until i'l run-out of fuel, good thing steering servo is workin', bout 5 min. boat running in full throttle, then i feel lil' relief coz i can manuever the boat comfortably with the V24 rudder in it, this rudder really change how the boat handles, i never experienced the violent spin and hookin',, to make the story short boat stop right infront of me...then checked the servo, it's dead, i have no extra so the test went short.

sorry guys no speed result yet, tom. after work be testing again.

Hesco Racing

Thats weird I see you throttle servo is a futaba and they are good servos. I dont like putting servos on their side, The engineer in me says that the servo will work harder as all the gears lay in one side of their wear surface thus putting drag on them. Just my 2 cents. Great to hear that at throttle it steers. That is a good rudder setup. did you leave it that length or cut it shorter. Seems like it protrudes more than the normal rudder out the bottom or is that how the picture is taken.

wave waker

thanks HescoR bout the servo, u know what u gave me an idea, i can really sit the servo upright and still will fit in the box[sm=thumbup.gif], and save extra space.


btw, ok folks, i had a good run this pm. first of all i want to say thanks to my major sponsor my work coz they let me go to the lake early

first run, x447 prop, 15% nitro, boat hardly go to planing, i can see the front hull step is still touching the water, speed attained 40.1mph[8D].

2nd run same set-up but strut was raised by bout 2 mm, speed goes 42mph but i'm not satisfied how the planing.

3rd run strut raised bout 3mm more and angled, speed drops to 38.6[:'(],,i think this time i went to high and prop can't bite no more, so i maintained the set-up and put x447/3 blades and hits 42.2mph,,i like how the boat rides it lifted in level instead of just lifting the bow...the acceleration is very impressive, lots of torque...OS .46 runs like energizer it keeps goin and goin and goin.

during the whole testing i don't have any violent turns and spin which is really common to tc31, so i think it's the pivot of the stock rudder that makes the weird thing...Very happy of how it handles at the speed of 42.2 mph still very stable...

engine turned the x447/2 and x447/3 pretty easy, with 3 bladed the ride is so smooth in turns and acceleration compared to 2 bladed.

though i ordered a skeg strut i might not need it.

boat will race this weekend in Indy under Open RTR hopefully,,then after the race i'l mess it again.

Things i need to do to gain more speed:
1. use 50-65% nitro
2. shorten the rudder
3. test different props
4. leaning the engine
5. try other tuned pipe
6. any suggestion u think, i run-out of idea
still lookin to hit the big 50mph barrier...pretty close but not yet there.

ryan_t888

Interesting I like the organized thoughts. Really looks like you have an idea on where to go, keep it up! [8D]

Ryan

zippymustang610

i think the higher fuel percentage and running the motor a little more lean should put you around 50 awesome boat and idea ive been following this thread im gonna be excited when it hits 50!

Ron Olson

My Feedback: (1)

Go with an 11cc pipe as the OS .46 likes them for some reason. Once you get it dialed in you should find that the X-450 or X-646/3 props might give you the extra speed that you're looking for.
If you use the big pipe that you have there, it's going to have to be muffled. I did some testing last weekend with a pipe that all I did was JB Weld a piece of brass tubing inside the stinger so that it runs as far as the fat part of the pipe. I didn't see any loss in power but had a much quieter pipe. I did drill out the stinger though so that I didn't lose any internal diameter once I put the tubing in. If it didn't work I could always drill the tubing out.

wave waker

Hey Ron, i have those props that u mentioned but never tested yet still needs balance and sharpening,,,do u know what's the big difference of x646 compare to 4 series like x447 or x450?

i tested the .90 pipe and yes it's loud, stingy to the ears, wish i could put stinger there to make it quite but i just borrowed it,,so far i'm enjoying the irwin quite pipe.

i'l keep posting here as i go along testing, for sure i have a lot of question while while lookin for the best set-up.

ryan_t888

Pitch ratio. The X6 series has a pitch ratio of 1.6 and the X4 series has a pitch ratio of 1.4. Multiply the pitch ratio by the diameter to get the pitch.

More pitch as you may know, loads up an engine more. Keeping diameter relatively small will decrease engine load.

Ryan

wave waker

thanks Ryan, big help..i think i need to install my engine RPM sensor to get compare accurately the difference.

Ron Olson

My Feedback: (1)

X-447, 1.85" dia., 2.59" pitch
x-450, 1.97" dia., 2.75" pitch.
I don't have the spec's for a X -646 but have one on the X-645. That's 1.77" dia., 2.83" of pitch.
I'm owrking off from an old prop chart but it still works for many Octura, Prather and ABC props. It's kind of cool as it gives speeds at certain RPM ranges figuring in a 15% slippage factor. If you want one, shoot me your address in a PM and I'll send you out a copy.

ryan_t888

Isn't it much easier going:

X447 - 47mm diameter 1.4 pitch = 65.8mm
X448 - 48mm diameter 1.4 pitch = 67.2
X450 - 50mm diameter 1.4 pitch = 70mm
X645 - 45mm diameter 1.4 pitch = 72mm
X646 - 46mm diameter 1.6 pitch = 73.6mm

No chart needed for Octura, it is that easy. For prather, a chart is needed. The Prather 230 (48mm x 76mm) or Prather 225 (47mm x 71mm) would also be another possible choice for a 45 engine.

Ryan


EDIT:

Prop Chart
http://www.xtremercboats.com/tech/propchart.htm

Copy/paste that in to Microsoft Word, then save it for a prop chart.

nothinbetr2do

thanks for the prop chart, i'm just getting into boats and got me a tc31 coming. so i'm sucking up all the info i can

ryan_t888

No problem! [8D]

I should finish off the excel spreadsheet I created that allowed for simple estimations and calculations. It has a lot of conversions and a simple to use speed/RPM prediction.

Ryan

wave waker

WOw!! great prop info. guys [sm=thumbup.gif],,keep it up...for sure lot of help to peeps there...

ok, back from indy race, [&o]sad to say no enough boat to make an Open RTR so no race for tc31, but i ran it during open water just to show-off a little, boat performs great actually better than my 2 out of 3 race boat acting so crappy [:@]the whole weekend...after makin' few laps i'd checked the engine temp. and noticed went high just to realised i used my racing fuel with 51% nitro[sm=lol.gif] instead of my fun fuel 15%nitro, that's why i'm kinda impressed how it runs, the difference is obvious..

hopefully, this week i can visit the lake and speed tuned it.

hey Ron, speaking of prop slippage i'm takin' it to consideration, since i got an rpm sensor and gps for speed, and the prop chart, i can tell the prop slippage of the boat...actually, this how i test if the hull is good or not.

hey guys i got this additional speed idea[sm=idea.gif] i want to try, i'l use a lifting prop strut, see the pics, the one in the left side is the lifting prop strut and the stock on the right, notice the bottom surface is flat compare to round, this is usually use in hydro's....during planing i believed this will help lift the boat and maintain the planing....i'm excited to try.....or maybe u guys can try it by doin some filing and sanding to make the stock prop shaft bottom flat,,,just don't blame me if something goes wrong[sm=drowning.gif][sm=bananahead.gif]

Ron Olson

My Feedback: (1)

Was that the Hydro Masters race? If so, start a thread with some shots and results if you have any. I had a chance to go down there and Don Templeton was going to let me crash at his place.

wave waker

sorry Ron, i didn't take pics this time...somebody posted pics n' result in the other website.


btw, got a chance to test run tc31 this pm and was happy of the speed i got, seems like it getting faster n' faster..well, first 2 tanks same set-up from the last run except i'm using 50% nitro, same prop x646/3 and getting speed of 43.6 mph, water condition is 1-2 inches ripple, boat really stable, then changed prop with prather 240 and speed bump to 45.1 mph how sweet

with x646/3 the acceleration is greatand smooth, boat is pulling hard, it's great on low to mid speed but it won't pull anymore on top end, i think due to 3 bladed more load to the engine and can't make more rpm...in comparison to prather 240/ 2 bladed, there is a slight speed lag during acceleration, low to mid is just good but on top end engine is screamin' with proportion to the speed attained.

still need more work for the 5 mph left to get the big 50 mph[8D]

wave waker

i got new speed today!! still running prather 240, 50% nitro, leaned the engine by 1/4 turn from the last time run.

since i changed the rudder the boat stability is so great,,,, ok, the situation is, it's windy here i would say 10-15 mph and gusty, water has big ripples, boat just riding on the waves either against or with it, except when running parallel with the waves it gets little jumping/jerky other than that no bouncing or hooking, no blow over..what surprises me is boat literally running wide open and handle the wake just like nothing.

as we observe it, i think boat can still run with bigger prop coz it accelerate great then about half of straightway acceleration stops but engine still screamin but no more additional speed, so far, we concluded that by this engine characteristic it's still a little under prop,,i'm lookin' for prather 245...