nitropower

GOT TO TRY OUT MY FIRST GASSER TODAY. EXELLENT DAY IN ALABAMA, ALL WENT WELL FOR FIRST TIME OUT. GOT UP TO 35.4mph WITH THIS 20+lb BOAT. GOT TO GET A BIGGER PROP CHECK IT OUT
NITROPOWER

tsunami

dang thats glassy
nice looking boat

ibuildstuff

is that a american rc ripper? cuz it really looks like one..

A few suggestions, 1. adjust strut angle, and raise the strut/drive.. boat is running wet.. make sure you have a retrieve boat to get it back in becuase you want to get it to the point to where its just about to blow over but doesnt.. youll prolly have it blow over.. thats why ya need a retreive boat..
2. what prop are you running?
3. what engine do ya got in there.
4. looks great!

Jesse

pro27

By RAISE the strut/drive, I assume you mean to raise the prop closer to the surface?

If so....this will not make the hull run dryer......it will do the opposite and allow the hull to settle more into the water.

To quote John Finch.........
"On a conventional hull with a cg that's 28-31 percent of the hull's length, the deeper the strut is in the water, the more the boat will be lifted out of the water.
Conversely, a shallow strut allows the boat to settle into the water, and this is one reason why surface-drive struts are so popular: they allow a model to settle. "

John Finch again...
"A conventional CG of 28-31% of the hull length makes the bow lighter, so the whole boat is lifted when the strut is deeper in the water. This applies to sub-surface drive (drive-shaft exits on the bottom of the boat) and surface-drive (drive-shaft exits on the transom) models."

This info can be gotten from several of his books as well as many published articles in the boating mags.
I also think many others will agree with this.

ibuildstuff

nonono, adjusting the strut angle to get the bow outta the water, and what i should have said was, adjust the height if needed.. that hull, runs best when the water is passing dead center of the prop hub (one blade of the prop in the water at a time)

Thats what i ment.

and btw, boating mags are a joke.
"i think many will agree with this"

nitropower

HI JESSE, IT'S A 58" CAT RUNNING A MID MOD ZEN G23 WITH A MIDWEST 2" BAND PIPE AND A S&B STOCK P270 PROP. I DID SOME ADJUSTING ON THE STRUT AND FOUND THE LOWER I RAN IT THE LOOSER THE BOAT GOT. BEST SPEED WAS WITH HUB OF PROP 1/4" BELOW SPONSONS ABOUT 2degrees NEGATIVE TRIM ANGLE. BTW THATS ME IN THE LAST PIC, GOT TOO CLOSE TOO THE SHALLOW SIDE KICKED UP THE RUDDER. SAIL BOAT DINGHYS MAKE NICE RETRIVAL BOATS!!!

TERBObob

My Feedback: (21)

NITRO,
The 270 , although a GOOD prop , DOES need to get a little work done to it . ( I also think a 275 would be better suited for that cat )
Put a little back cut on her ( use your dremel , throw a barrel sander on it , and notch the prop about half of the diameter of the barrel sander ( but not quite half - just a hair less ). Then take and sharpen the heck out of the inside of the props edges ( inside meaning the side where the water gets picked and pushed off the blades ) Sharpen her till she is so sharp , that it feels like a razor blade ( if the prop is a SS one , no worries , but if its a berillium copper one , be CAREFUL of the dust and sandings that come off .... VERY harmful to your health . Be sure to wash your hands VERY good when done sharpening . Also be careful when sharpening ... MANY fingers have turned into hambuger meat from sharpening props ) .
Now , after notching and sharpening , make sure she is balanced .
This will allow the prop to load a LOT better .
The pictures are decieving here , but that boat doesn't look like she is getting near the speeds she should .
You might also consider a 7016/3 .... or a 7018
Like I said , the Prather props , although a VERY good starting out prop , will not give you optimal performance . ( I am not saying that they will not work good , just , that these are "basic starting out" props . )
A X475 that gets "voo-doo'ed" by one of the prop benders , would also be another possible good choice . ( If you want to bend your own , always remember , when adding more pitch , the edge is NOT the section to totally concentrate on . You make to make 3 little lines on both sides equally with a thin pencil -direction - from the hub , outwards , then grab hold of your pliers and bend a VERY little , starting FIRST at the line that is closest to the middle of the prop , then for your next test , go inwards to the next line and again , VERY little bends till you get where you want . Remember , you can OVER bend ( add TOO much pitch and totally defeat what you are doing ) When doing the bending , try and make as SMOOTH of bends as possible with OUT any "angles" in it .
One more thing ... why do you have a 2 degree negative strut angle ? THIS will make the bow ( front ) want to stay DOWN on the water . When you set her to zero , how does she run ?
BTW ... nice clean setup . I notice that in the 3rd picture in the first posting of your pics , the hull looks like she is riding prefect ....
Would you mind taking a few pics of the transom hardware and posting ? We might be able to solve the situation that way , better .

magyarbacsi

Nice cat.
That looks like an Expresscact's Thundercat, or its copy by forabuck. I have the same cat, and will scoot with a 260. You are right with raising the strut. Did not take much, 1/4 above sponson and did two blow-overs in arow. retrieved it the first time, flushed it, got it running just to do it again. Slow lerner. Actually it did it so fast I did not see why untill I looked at the pictures. Will try to post them.

magyarbacsi

Bob
I have seen the cut you described, the partial circle out of the rake, but I have not heard the advantage of doing it. What does it accomplish? Is an Octura X480 prop that is basically the same as a Prather 275 a better prop. I know its easier to sharpen and balance then the ss prop, and the top of thr rake is rounded. The Prather has a sharp point.

TERBObob

My Feedback: (21)

That cut , also called , BACK CUT , or some call it TEXAS CUT , allows to motor to spin up more freely with a MAJOR load ( bigger pitched , or larger diameter prop ). which in turn then allows the prop to start out with less load on engine and allowing it come on pipe ( as the saying goes ) almost immediately .
Stops the "bogging" effect when taking off and has NO effect on top end . ( no loss of speed ) Since there is almost NO water being "pushed" from that area of the prop but rather it is getting "bounced" back and forth from blade to blade .
For example ... when I first threw a 280 on a deep vee I have , it ran like molasses in the midle of January ( - well , here anyway - LOL ) ... couldn't get the most out of the prop. She would not have a good take off and NEVER got that nice TOP END sound outta her .It was not allowing the engine to "unwind" . Doing that cut , allows for FULL potential of the engine , making less load being put on the take off area of throttle , and has no change in overall top speed . ( this is where you see some boats "jump" and do "wheelies" when they start off )
I then did a back cut and wha-la ... she not only ran FAST , but had GREAT take offs and got on pipe in NO time at all !

Doubledog

My Feedback: (48)

Boat Looks good. Real good.

You guys were in short sleeve shirts? What the heck? My folks live up in Spanish Fort and they're talking about mid 20's

Here's a few links for some prop mods. Good reading.

http://www.rcprops.com/rcprops/index.html

http://rcboat.com/prop.htm

nitropower

TERBO, The 270 is the only prop I have right now that engine will pull. I have a x482 that is too big,but i am in the process of modifying it. I do not have a lot of expirience with modding my own, mainly T & E.[sm=idea.gif] In the 3rd pic top hub of prop even w/ bottom of sponsons, trim angle +1 or 2. I dont have the new 4 port engine mine is older pum 2 port, I did find a deal on a B.H.Hanson Indy cyl and piston to make more power. This thing is HEAVY!! On the transom I have a Octura strudder, not the best for speed as rudder is directly behind prop. I did raise the rudder 1/4" to get lower pivot block out of the way. Need to get some more props, don't have anyone to borrow props from, seems like I'm only one in my area with a boat. All airplanes and cars.Not even a LHS exept for a scale boat shop. I have to get most of my stuff off the web.

Thank's for all of the info on the prop mods, I have found some pics on different web sites but their instructions were vague. With the info you provided and these pics maybe I will get the 482 to run yet. Oh yeah, btw, I was running the down angle the first few runs as I have set the c/g at 28% and did not want to blow over first time out-- (had quite a few spectators)


magyarbacsi, thats a forabuck hull. Great hull imho a little heavy but thats good for me because days like the one pictured dont happen often. It usually has about a 6 or 8" chop to it.

Will post some pics of transom alittle later camera battery dead
Nitropower

nitropower

PHCM No short sleeves, but that is me? there barefoot after I ran it aground and kicked up the rudder. Will be colder here tomorrow after it rains[&o] so I'll have to keep warm in the shop modding some props. Thank's for the links I need all the info I can get.
Nitropower

Doubledog

My Feedback: (48)

I've got a used x482 on the way just for modding purposes. Its a lot of prop even for a 260.

You've got the right idea about it so far. Just remember, start with one mod, run it and check your speed/handling. If that doesn't work, do another one to it.

I just bought 16 props today and they'll be here by the end of the week. Sweet deal too.

ibuildstuff

oh its a cat, couldnt tell from the first pictures.. then disreguard all of that..

try a few thinks.. even tho thats a big cat, you should beable to get about 45ish outta that cat with ease. Where is your strut height at now? Set that strut flush with the bottoms of the sponsons, then click the trailing edge of the hub up about the height of a steel ruler (about 1/16th of a inch) do push the back of the boat down a tad and get the bow up in the air. Any boat gains speed by packing air under the hull.. and cats/hydro's are expeciailly sensitive to this. The more air you pack under there the faster you go, with the right prop and adjustment on the strut, you gotta find the point where she wants to blow over but doesnt. Those prather props are decent to "beat on" or get a "basline" with but not really good for much else.. they are a dime a dozen.. try a abc mw3 or a abc h-50... the 275 can be made a WHOLE lot better with some pretty extreme mods if ya need a prop mod done, shoot me a email.. i can do it for ya or tell ya exactly what would need to be done with that prop to get some extra umph outta it.

Another thing, did you cut your header? sounds like you need to get that pipe tuned it.. (btw.. GREAT pipe) is it gettin on the pipe? move the pipe in and out a 1/4 inch at a time, see what gets ya faster... those pipes are pretty particular.

Anywho hope this helps ya.

ibuildstuff

the x482 is a good prop, but needs the cup taken out (texas cut will do that) and allow that prop to really push that boat.. if the top of the prop hub is even with the sponsons, then its too low, move it up 1/8th of a inch to 1/4 of a inch.. it makes a huge difference.. you wanna get the middle of the prop hub passing through the surface of the water.. we will get that boat over 45

nitropower

PHCM i was looking at those too. 16 was too many for me, BTW what are you going to do with the 4 bladed prop? Would you consider selling it? Thanks again for the info.


ibuildstuff
I do not know how much power I have. I bought engine, stock 2 port pum23 bolted a modified cyl. on it and the pipe and header combo. The header was alredy cut really short, I do not have a tach yet but it is getting on the pipe. Just curious, I have a muffler on it. When I took it off, not having changed anything else, it slowed down .5mph. Do I need a longer header pipe? Also I have a hanson Indy cyl. and piston i bought to get some more power. Probably need a bigger carb too, I dont think the 167 is big enough. Would a 644 be a good choice?

On the strut height the top of hub is even with bottom of sponson, w/0 to 1deg + angle. I have c/g set at 28% in case I ever wanted to put a clutch on it. I'm really just a sport boater, but I do like to go fast!!

TERBObob

My Feedback: (21)

From my experience running the 482 , I would only loose some of the diameter ( 82 mm is QUITE large for a 230 PUM ) , and not the cupped part . Again , that prather will do you fine , just throw a back cut on her ... ( I , too , only run 230PUMs ... ( four of them currently , and all less that 1 year old - got them from BONZI for a GREAT deal when the change went to those 260's )
Also running all QD pipes single cuts .
About the hull ...... Next , time , ( FTR ) , Vern makes a GREAT hull , but he ALSO ( unlike the other manufacturers ) allows the buyer to choose which glass weight AND what weight the end result will be ( with a minimun ending up of 9 lbs using .5 glass )
The hull , ( yours ) although she may be a bit heavy ... is good ...
Reason - IF ( and I hope you don't ) , but , IF , you DO hit something because of radio intereference , or maybe lowe batteries , or whatever ... that thicker hull will take more of a beating .
Got remember .... lighter is NOT always good ... ( unless your one of those "racers" )
If you ever went to PAUL G's website and read what he says about prop shaft height and all , you will be RIGHT on target ( so close that its not funny ) .
And FTR - Paul G also has the site listed above with all the prop mods .
Granted , he bases his around that STRYKER F-41 cat , but the info is still a terrific basic for ALL cats ... ( except Eddy B's SUPER CAT which I understand requires a totally different setup than the norm )
And sorry ... not really sure how much , or what is done exactly to a INDY jug . ( I do my own engine mods )
But , I can tell you that I had to go to a 529 Walbro on the twin Zens I did for my 60 inch cat . Wasn;t enough there out of the 267's for the motors and went to a 529 and got a LOT more take off power ... ( top end basically remained unchanged , BUT , they DID give more ummph at bottom end and midrange )

nitropower

ibuildstuff
If I raise strut to 1/4" above the 270 cavitates bad when i turn. I need to get some different props to play with. Have to do it piece by piece, already have over 1200$ invested in this project. and from what i have seen on others boats thats just a drop in the bucket.

Thank's for all of the help guy's it is greatly appreciated
Nitropower

ibuildstuff

yea boats are not cheap.. BUT, if you have a simple tool such as a dremel, its quite possible to make all of your hardware, do your own mods, tune your props, and whatever else needed.. Ive made some stuff and it works just as good as the 100 dollar job you buy from wherever, made mounts for previous boats that work just as good and look just as good as the 75 dollar mounts, if ya need some tips on how to make some hardware lemmie know.. im workin on some carbon fiber hardware as we speak. but all in all bro, its not that bad.

pro27

Well, if what you said originally is not what you meant, then why say it? Misinformation is confusing.
As far as the mags go, I wonder if Dunlap, Finch, Aberle, Pond, Turner, Hetmanski, Eyrich, Hobbs (the list could go on and on) agree that the articles they submit to the mags are jokes ! Articles by these guys have helped me since the early 80's, and it is their articles that have helped keep me in the hobby by expanding my knowledge base.
I have to disagree with you!

ibuildstuff

and THATS why those guys names are not really known... yea dunlap is known.. and prolly to the rest of you guys those guys are "big guys" but are any of there hulls winnin races?

Theres all the proof ya need.

Joe Petro

My Feedback: (1)

Do you think 28% is ok for the CG?
I have one of these, with a stock 260, and was going to go to 30-32%.
Should it be farther back for this large hull?

Joe Petro

nitropower

Hi Joe, I set the CG on mine to 28% because I have the old 2 port g23. I was worried it would not have enough power for this large hull. I also have future plans for a full mod g26 maybe w/ a clutch, so i have some room to move engine foward.
If your engine is modded you might want to go closer to 30%. Also depends on what the total weight of the boat is, mine is over 20# w/ fuel.

What works on one hull may or may not work on another.
Nitropower

Freakazoid

My Feedback: (1)

Im new to nitro boats, but im just wondering, Is your gas tank really a kind of balloonbag?
The picture looks a bit like the gas retainers are all floppy.

Im just curious why, thats all. [8D]