V-Tail

My Feedback: (1)

Hi all,

I've read good things about the Tower muffler on an OS 46FX for hovering. Is it true that it will add 1000 rpm over the OS muffler? I've checked the numbers on the Performance Specialties and Jett mufflers but the Tower price seems almost as good and much cheaper! Would appreciate any thoughts. Thanks.

w8ye

My Feedback: (16)

I don't think you'll get a 1000 rpm more out of it. From my experience it's more like 4-500 using the same prop.

I'm setting here looking at a OS 46 FX with a Tower on it and if you didn't know your model engines, you would think it came on the motor. There is also a MDS48 setting here with one on it also.

Keep in mind that when you put the Tower on, you will have to reset the needle valve.

Also keep in mind that the Tower muffler, if run har, will try to come apart on you. The back end of the muffler will come off and fall out there in the corn somewhere.

The best thing to do is to put a threaded rod all the way through it with double nuts and Locktite on both ends. They last till you break one in a crash that way.

Jim

V-Tail

My Feedback: (1)

Thanks for the reply. You know how removing the baffle on the OS muffler will increase about 400 rpm on a 10x6? Are you meaning that the Tower muffler will be an additional 3-400 rpm above the OS muffler with or without the baffle? It sounds like the Tower is like a OS muffler without the baffle, but with the threaded rod with nuts! Have you ever tried PSP or Jett or Macs? Thanks in advance.

Ed

w8ye

My Feedback: (16)

I personally havn't used anything but the Tower muffler. I always figured that the extra complexity and cost of the alternatives was not worth it to me. But if money and weight are no object, then by all means, 'go for it' The Jett muffler is a tuned chamber wound in a coil. The PSP (I've never seen one) I figure to be more like the Ultra Thrust than anything else. The MAC's Quite pipes are a little broader in horse power than the 'peaky' straight tuned pipes. And as I have said before, the MACS one piece muffler is just that, 'a muffler". You would have to drill out the outlet to try to get as much power out of it as you do the original OS muffler.

The Tower muffler is more "tuned" than the OS muffler without the baffle. Speaking of taking the baffle out, you should do that first and see what you think? Especially since your interest is hoovering. Oftentimes on here you will see claimed figures that you will not be able to duplicate yourself. You, in turn, will think that you didn't do something right? Another thing about the claims of rpm increases as a result of taking the baffle out or installing a Tower tuned muffler, there are a lot of variables like the prop size, fuel used, and the weather.

A smaller lighter prop on the engine will respond better to exhaust effects.

A smaller, lighter plane will also respond better to tuned exhaust and smaller prop situations.

Often times, the tuned pipe on a pattern type plane is used as an engine "speed regulator". If the airplane is climbing, it will get on the pipe and as the airplane is diving, the engine will get above the pipe.

If you are going to get into the tuned pipe business, you need to be thinking about a 9-8 prop instead of an 11-6 or 12-4 or 12.25-3.75. The small diameter higher pitch prop will allow the engine to rev up quicker and get "on the pipe" and the airplane to build more speed. But have less hoovering ability.

But remember, this effect would be more pronounced in a smaller - lighter - more streamlined airplane than a large - heavy - bulky one.

You mentioned hoovering and that is a static thrust versus weight situation. Typically you would use the 12 - 4 or 12.25 - 3.75 props to develop maximum static thrust. Then you need the lightest plane you can find with a lot of wing area and airfoil. I'm talking about a plane under 4.5 lbs for a .46.

In the hoovering process, you have to juggle the throttle all over the place to keep the airplane still. Therefore a tuned pipe with a narrow power band is not in your best interest.

One of the biggest factors in performance is weight. Your money would be better spent getting a Magic or Magic extra or some plane like it.

The Magic is specifically designed for hoovering and 3D type manuvers. They advertise it at 3.5 lbs but you would have to use Hitec HS 81 servos and a 6 oz fuel tank w/ a very small lightweight NMH battery. Otherwise, it's going to be closer to 4.5 lbs. The Magic ARF sells for $99.95.

lite weight is king!

Jim

ramcharger

I have an OS 46FX with many many flights and it will turn a 11x6 MAS prop right at 13,000 rpm with the baffle honed out of the ring and 10% Cool Power fuel. I keep the ring in for sealing purposes. I have a 2 to 3 year old NIB GMS 47 with the same muffler as the Tower I believe. I installed and flew my OS46FX/Dazzler/GMS muffler and didn't get any appreciable increase in rpm. It tached at 13,000 and may have got to 13,100 rpm for brief moments. I can now say I have an unused NIB GMS 47 engine with a used muffler.
I will probably install it on my OS 46SF powereed Dazzler this weekend. That engine could use a boost although its rpm is gradually increasing flight after flight but cannot come close to my OS 46FX even with a 11x5 prop and same fuel.

vertigo

My Feedback: (1)

Hi V-tail,
If hovering is your interest the Psp and Jett tuned mufflers may not be the best thing for you even though they will give a higher output, rpm. It's been my experiance when hovering with the PSP tuned muffler I'm constantly on and off the pipe when hovering. The tower muffler just as the stock muffler will give you a much more tractable midrange for hovering.
Ditto for all of w8ye's comments.

Happy Hovering

Kris3D

My Feedback: (1)

After taking the muffler baffle out of my os 46 fx, I received a 1000 rpm gain. NO JOKE. I was using an apc 11.5x4 on 15% nitro.
The week before, I had received my tower 46 muffler that I was going to try, but I decided not to because I saw such a big rpm gain with taking the baffle out.

Kris.

1Jimbo

My Feedback: (2)

I must have done something wrong, I only got a 300rpm increase.

airwethead

I put a tower muffler on my 46FX.
800 rpm better than the stock OS muffler.
500 rpm better than the stock OS muffler with the baffle removed.
The tower muffler did fall apart rather quickly, however. It kept vibrating the nut off the end and letting the back half of the muffler rotate. I finally tightened the nut to the point that I stripped the threads of the long screw that holds it all together. The fix was simple and has been permanent. I left the old nut on there (as a spacer over the stripped threads) and put a .10 cent Nylock nut on behind it.
My OS runs much better with the Tower muffler, worth the effort!

rvd

I think the tower muffler is like the GMS .47 muffler..
I put a gms muffler on my friends TT .46 and it woke up.. The engine already runs good from factory but the muffler woke it up even more. I still like my gms .47 for a 40size plane but they are cheap. Almost every one I have leaks from the front bearing but they scream. I have done side by side tests using 15% wildcat 10x6 props and the gms .47 got 400 rpm more than the O.S .46FX. What does this mean?? Not much . You would not notice that in flight but it's good to know that it can run with the best of them..