MustangN8S

A guy at my field says his 55AX Revolver will be faster then my 115 set up...."it don't turn any RPMS"....well see...No RPMS, but it should turnthe crap out of a 13x10-12 prop

How fast do you think I should be able to get out of this thing? I'm guessing 110 or so?

YUKONFLYR

There is little replacement for displacement so your saito powered revolver with the right prop should give the 55ax guy a good run for his money. The revolver flys nicly on a 12 inch prop so get as much pitch as you can on a 12 in prop, maybe 12x10 to 12x12. Should be speedy.

airraptor

My Feedback: (66)

lol sorry but do not run the 12x10 or 12x12 prop you will be so slow he will have to throttle back hiss 55 to stay with you.

try a 14x8 apc on 30-35% and will be faster than him for sure. i have the 125 on mine and turn a apc 15x8 at 9700 and scoots along. i would like to run a 14x9 but havent found one yet. a 16x7 might be faster but havent flown it yet.

to go fast you need more thrust than drag. well the revolver is draggy so need lots of thrust. the 14x8 will be perfect for you. try to pro the 115 for about 10,300-10,500 on the ground with props less than 9" pitch

the 10 and up props are stalled on the ground and generaly have a higher rpm on the ground than in the air or stay the same. these props load up more in flight unless you get going over 130 or so.

freeair

to go fast you also need correct weight not over weight. i feel the 115 size 4 strokes are very heavy for this sized model and i bet you also have to add tail weight to get the cog right. my Revolver is powered by an OS 55ax and Jett Pipe, normal prop sizes in Australia are 11/x 6 or 11 x 7 apc type, i run a 10 x 10 . bye bye 115 catch me if you can.

MustangN8S

We will find out..

I went with the Saito 115 because it's very light compared to other 4 strokes in its class. It weighs the same, or less then most .60 size 2 strokeengines. And it's about 3oz heavier then the 55 AX. I also refuse to add weight, I will move things around to balance it ( Battery etc.)...

With a dragy airframe, I think the 55AX and small prop doesn't have a chance against a 13-11 / 14-ish props turning 10,000

Here is a video on youtube of one www.youtube.com/watch

Watch the first pass he makes after take off......I've never seen a 55AX move like that

russm

draggy airframe? it is the  most slippery sport plane i have flown.

Robsauto2

My Feedback: (2)

How would the power output of a YS110 compare to the Saito115?

freeair

the YS 110 would kill the Saito 115 in power output. even though i dont really like the tuning of the YS engines compared to the docile Saito.

freakingfast

My Feedback: (3)

I think if the right prop is on the Saito 115 it should take the OS 55. A more even match would be a Saito 82, however the OS55 on a tuned muffler would fly much longer because for some reason I have found that the 82 engine drinks fuel like a drunken sailor when it's ran continuously at full throttle. Since that's about the only speed I fly, I had to get rid of two 82GN because I couldn't afford to feed them.

z06kal

You're not going to go faster than prop pitch speed in level flight.   I've clocked many many planes on radar and never ever seen it happen.   Something like a 14x9 will yield great thrust and vertical performance but you would have to turn it at 14,000rpm to get to 120mph.   I'd say something like a 13x12 or 13x13 would be the way to go on the Saito.   I have the great planes minnow which is draggier than a revolver and I run a 13x13 pattern prop on E-power.  It turns about 11,000rpm and does an honost 122ish mph in perfectly level flight. 

airraptor

My Feedback: (66)

lo are you sure you wont go faster that pitch speed??????

what i am saying is that much pitch your not going to get the plane up "on its plane" so to say. you run your 12x12 AND I run my 14x9 and lets race!!

z06kal

I'm not sure what you mean by "getting it up on its plane." IF your prop is too small and thus lacks the thrust at pitch speed to overcome the airplane's drag at that speed than the plane will fly slower than pitch speed. THe difference between what the pitch speed is and what hte plane is actually flying it is often called "prop slip" by pilots. When the prop is properly sized there will be less "prop slip" and the plane will fly rather close to pitch speed. If the prop is undersized there will be more and more slip depending how undersized it is. At the extreme example would be putting a litte 4" x 4" prop turning 30,000rpm on a giant scale plane. The plane may not move at all which means it is all slip and no action.

Now there has been some argument about exceeding prop pitch speed due to aerodynamic lift generated by the airfoil on the prop. There was a whole thread about this as it pertained to a patriot. Pitch speed on a prop generally means how far the prop will travel in a single rotation through a chunk of clay. That is if you put a 9" pitch prop against clay and turn it one revolution it will travel 9" into the clay.Now this extra lift does existand it may be quite substantialon a much largergiant scale or full scale prop where reynoldsnumbers are far higher. Through my imperical observations taching and then clocking lots of planes on radarsuch as fast pylon racers F5D/F3D/Q40 etc, fast war birds, etc etc I have never once seen an airplane fly faster in true level flight than what the pitch speed says it will at the assumed unloaded rpm. This includes incredibly slippery planes such as F5D where any extra lift from the prop airfoil should be realized and measurable but I've never seen it happen.

I've drawn some graphs to illustrate the relatoinship between airplane drag, prop sizes, and prop pitch. These are just completely off the top of my head and exagerated for emphasis. However it should be clear why you can't fly faster than pitch speed. This is because the prop is not producing any thrust at flight speeds that exceed the props airspeed infact quite the opposite it is producing drag.

ChrisAttebery

My Feedback: (15)

I'm flying a Phoenix Strega with a YS 110. On 20% It turns an APC 13x11 at 10,200 on the ground and has been radared at 125mph. I think you'd be lucky to get either the 55 or the 115 to match that. You're going to have to pitch up to get any speed out of the Saito.

The guys racing the Warbirds with the YS110s use 45-60% nitro and a 13x13N or 13x13.5N. They are getting speeds in excess of 140mph.

airraptor

My Feedback: (66)

well i still race ya lol and i am pretty sure i would kill that little 55.

those warbirds and 40-60% are turniong that prop at 12,500-13,000 on the ground.

i do believe that you can fly faster than the pitch speed. as far as those pylon planes and little props they dont have much of an airfoil to contribute to the lift/thrust of the prop. Or atleast I dont think so.

I do know my revolver is faster on a 15x8 cut down to turn about 10,000 on the ground. the saito 125 turns a stock 15x8 apc at 9,600.

I have tried the 13.5 10N ,13x11, 13x10,12x12, 12x13 and the larger dia. and lower pitch were faster.

z06kal

Raptor look at the Engine RPM at each speed and do the math the bigger pitch might be bogging the motor to much so it never gets into the power band. Come on out to the sepulveda basin next month we have some good events coming up a warbird race and a jet rally. I'll bring the gun out and we can clock any planes you bring and get some real world numbers and comparisons. BTW like I've said I've only clock a few hundred planes and not a one has flown faster than pitch speed predicted... sooo I dunno what to say.

MustangN8S

I don't expect to be any faster then the YS, they do produce some good power. I thought about buying one for this plane, but I decided against the extra weight. This is going to be more of a Sunday plane so I went with the Saito...I think with the right prop to run the engine in it's powerband, It will give some decent speed.
It won't be faster then the YS 110, but it should blow the doors off the 55AX IMO...

Buddy at my local hobby shop says the 75AX is a great match for this plane also.

airraptor

My Feedback: (66)

ZO6 i will try to make it out there after the summer. my kids are here now but are leaving in aug. i dont have any warbirds now my K-61 and the strega went in awhile back. i am putting the H-9 back together(broke the tail off in the move) it just has a 120AX and pipe on it. its slow at 110 or so. i do know i have the fastest revolver there. faster than a f-20 with 55ax and jett muffler. its all fun here either way i do make all my planes faster than everone else's even with same engines lol. send me a pm with directions. thanks

russm

i hasve the rev w/ the 75ax. not sure about the speed but it is a nice combo. just moved to az and am trying to get some of my planes sent here. only so much room in a jeep g c. guy out here has a gps. would like to know what kinda speed the rev is geting w/ my setup. started out w/ a t.h. 75. that was faster than the 75ax. if you look at the other rev link in arfs and rtfs, cav is geting 148 w/ a jett 90lx. he was able to use the stock lx muffler . pretty slick installation. saito makes a fine engine, but its made more for acro type flyng, not speed or high rpm. ys is the way top go for speed w/ a 4 stroke.

lippucci

RUSSM

As I recall, you use a "toni" landing gear. Is that from a "little toni"? If so, is it reducing the nose over problem in high grass? If not, which landing gear is it? Thanks.

Norm

russm

yes, it is the gp lil tony. much stronger than the weak landing gear that comes w/ the rev.