Fox 35 mufflers

Believe it or not, I only recently acquired my first Fox 35 Stunts (I should have shares in OS stock). One is a Silver Foxx, a way cool Fox, by the way. Very pleased with the easy handling and the power. Very gutsy, thank you very much, Lew. But, I have tried a tongue muffler and the smaller cylindrical Fox muffler and this thing rattles the windows with either one. We fly in a fairly noise sensitive spot, so I could use some help. What mufflers have you guys tried and found to be effective?

I have been running a OS MAX #762 muffler...I believe it originally came with a .25 FSR and some of the stunt FP .35 & .40's (it fits the FP 35/40 as well) I cut the very tip off and opened it up so that the opening is 3/8" but if you try one run it unaltered and see how it performs... My flying buddy seems to think it's too loud as I have it.

>Believe it or not, I only recently acquired my first Fox 35
>Stunts (I should have shares in OS stock). One is a Silver
>Foxx, a way cool Fox, by the way. Very pleased with the easy
>handling and the power. Very gutsy, thank you very much,
>Lew. But, I have tried a tongue muffler and the smaller
>cylindrical Fox muffler and this thing rattles the windows
>with either one. We fly in a fairly noise sensitive spot, so
>I could use some help. What mufflers have you guys tried and
>found to be effective?

I don't know what you call offensive, but all of our engines are going to create a certain amount of noise. And a small, light muffler is going to all noise or cause a reduction in power. Some, such as many factory mufflers (OS come to mind) are quite restrictive in an effort to keep size and noise down at the same time.

We use an Art Adamisin muffler tube muffler on the Fox 35 and find it gives a good compromise between noise reduction, total weight, and power reduction--better than the Fox muffler in all respects. If you are looking for total quiet, however, you will need a large, multi chamber muffler or need to go to a 4-stroke.

I have been experimenting with modified mufflers for a while. I have got the noise down to where you can hear the prop over the exhaust with minimal loss of power. Weight is minimal too, but frontal area is another story.

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Un-canny!

Len:

I'm the field marshal at KD's club field. We have a really touchy noise situation and absolutly enforce 90 db at 9' with 2 noise meters and written records for our sessions showing plane, engine, muffler, prop and ground and air readings. It's a pain you know where but the club has done it for a decade and when push came to shove with the local government last year, it was a big factor in holding on to our site. Even impressed the State PCA folk---and that's tough to do.

KD is a great guy who tries to meet both the letter and the spirit!

Thanks for the help,

> Len:
>
>I'm the field marshal at KD's club field. We have a really
>touchy noise situation and absolutly enforce 90 db at 9'
>with 2 noise meters and written records for our sessions
>showing plane, engine, muffler, prop and ground and air
>readings.(snip)
>KD is a great guy who tries to meet both the letter and the
>spirit!
>
>Thanks for the help,
>
>Jeff W

90 db at 9 feet should be easily attainable with either the Adamisin tube muffler or any one of several tongue mufflers. I know. I have a db meter and have taken measurements--not with the Fox, but with the FP and Magnums. If those pass, the Fox should pass, too.

The Art Adamisen tongue and expansion tube mufflers are available from Brodak et.al. The tongue does take the edge off the noise and is pretty lightweight as well. The Fox muffler seems a bit quiter and is good if you can use a bit more weight up front. Neither gets close to OS noise levels with factory mufflers.....but I wouldn't call the sound levels "offensive."

There was a previous post ....probably 6 months to a year ago regarding decibel levels with various configurations. Wish I recall who took the measurements. Does make a good case for mufflers, though!

I would advise caution. As in I have yet to see a good-running Fox 35 which is also decently quiet.

Back in my early days of CL Stunt, having finally overcome a bit or arrogance as to "what works," this compounded by the NIH syndrome, *all* of the tricks pounded into my head by Don McClave were being utilized. Including all-castor fuels at outrageous percentages having replaced my home-brew pink Kool-Aid fuel.

Less only one. I liked the looks of the Big Art tube-type muffler, it did a marginally better job of exhausting as opposed to dispersing crap all over, it sounded nice, knew it to be better than stock Fox piece, needed nose weight in models in use at the time.

Tossing up my hands, I installed NW muffler of choice for Fox 35, the RSM tongue ("chip") muffler, all holes drilled to .078 inches. And added nose weight. No other changes.

Instantly my runs were given McClave Seal of Approval.

Noisier? You bet. Even more creeping crud all over the models? Ditto.

But it would take an act of God before tossing my RSM tongue mufflers away, even if on the light-and-cheesy side of the equation. And they are...

Dan - Seems your impression of the Big Art expansion tube muffler is the about same as mine....looks good but performance not quite right. The OEM muffler is quite ugly in my book, but we get decent runs and good power. I tried the RSM chip muffler and glad you mentioned the hole sizes..'cause I'm about to drill mine out. The Big Art Tongue seems OK as is, although I drilled one out as an experiment....didn't improve power that I could tell.

Yep, I hear what you're saying. In this case, though, I can afford some power loss. This Woolard Fox has plenty of moxie for the plane it's in. But it has a really raw exhaust note that is very unpleasant. I mostly want to just mellow it out enough that I can enjoy running it. I have an OS FP muffler and a Tower 40 that both can fit. The OS is smaller, lighter, and better looking. Will try it first.

Our relationship with one of the neighbors has been less than, uh, cordial. So we do our best to keep our end of the site agreement.

Interesting. I'm also finally hearing some of the things I've been reading here or been told many times......

Kelvin

>I would advise caution. As in I have yet to see a
>good-running Fox 35 which is also decently quiet.
>
>Back in my early days of CL Stunt, having finally overcome a
>bit or arrogance as to "what works," this compounded by the
>NIH syndrome, *all* of the tricks pounded into my head by
>Don McClave were being utilized. Including all-castor fuels
>at outrageous percentages having replaced my home-brew pink
>Kool-Aid fuel.
>
>Less only one. I liked the looks of the Big Art tube-type
>muffler, it did a marginally better job of exhausting as
>opposed to dispersing crap all over, it sounded nice, knew
>it to be better than stock Fox piece, needed nose weight in
>models in use at the time.
>
>Tossing up my hands, I installed NW muffler of choice for
>Fox 35, the RSM tongue ("chip") muffler, all holes drilled
>to .078 inches. And added nose weight. No other changes.
>
>Instantly my runs were given McClave Seal of Approval.
>
>Noisier? You bet. Even more creeping crud all over the
>models? Ditto.
>
>But it would take an act of God before tossing my RSM tongue
>mufflers away, even if on the light-and-cheesy side of the
>equation. And they are...
>
>Dan
>

You might want to check out the MACS one piece mufflers:

http://www.macspro.com/onepiece.asp

To my ear they do a reasonable job of quieting without a lot of power loss...

As a fan of the Mac's Muffler, I'm sorry, but I can't imagine it is even available for a Fox .35S. Or that it would work unless you abandon the 4-2-4 concept. You might, however, want to try a Magnum XL .25/.28/.32/.36 or XLS .32/.36 muffler...all the same unit, same bolt pattern, fits a Fox.

To tell the truth, in your situation, an OS .25LA (with the stock muffler) is about perfect. They are so quiet that it is difficult for the judges to tell if they are running or not, from across the circle. Admittedly, this is from the upwind side, but it is still quite a shock. Steve

Phil: Good way to cook your Spaghetti-Ohs.

Kelvin:

"Less than cordial"----that's the biggest understatement since the lookout at Pearl Harbor said "do I hear an Airplane?".

Seriously, thanks for your help in keeping things going and quiet.

Our relationship with one of the neighbors has been less than, uh, cordial. So we do our best to keep our end of the site agreement.

Kelvin

In that case, you can just toss any and all Fox 35s back in the engine drawer. Unless you want to be forced to find another place to fly.

There was mention of "power," and while one never knows what exactly is meant by this, although in the case of CL modelers word is generally used incorrectly, I wish to point out that I referred to never having seen a good running Fox 35 that was also quiet. "Good running" takes in quite a lot more territory than whatever is meant by "power."

Finally, this is not really a problem. Instead, it is an opportunity. Try 25LA if you must have an off-the-shelf engine. Leave stock muffler on it unless you can *prove* whatever after-market piece chosen is better. (Good luck.)

You may begin to actually enjoy the peace and quiet, being able to communicate effectively with your flying partners.

Dirt-again I hear the point you're making. Maybe it's the motor/airframe combination, but this thing sounds harsh compared to the other Foxes I've listened to-including at least three this weekend. I'd like to change the tone of it to a more pleasant sound. I'll try some muffler swaps and see what the problem is. Or wrap the whole thing up in duct tape-the Minnesota solution. I thought maybe someone had a setup that worked well for them. But it's a sport/fool around airplane and if it comes down to a motor change, I'll use it as a wall decoration.

Jeff-thanks for the good words.

Kelvin:

You're welcome! Nobody deserves them more than you and Ryan!

Not to say I'm a bit prejudiced, but if you look you'll see that Fox 35 I won at the raffle Sunday was in the Classifieds Sunday night.

Take care,

Kevin, you already have the lightest 35 ever made why not compliment it with the lightest tube muffler ever made,almost 1/2 oz lighter than that old FP muffler your thinking about.You can look @ my web site @http://hyflomuffler.com then click PRODUCTS As you know the muff will fit some of your future motors as well and if your not happy Im not happy..send it back no prob! I have a Lew Woolard Fox I run on a 40 oz profile with a 10/5 BY&O on 5/29fuel, 60 foot lines 4-2-4 all the way- its a nice soft tone.Well hearing is beleving! Give me a ring if you like @ 805-526-9074 Scott Dinger hyflo@dslextreme,com-Email

This comment probably isn't worth anything, but it seems strange that our model airplane engines bother the neighbors, yet they have no problems with cranking up their chain saws, leaf blowers and weed-eaters which, in my opinion, are louder than our engines.
Glen Wearden

Me thinks its frequency and the doppler effect that bugs people.

Probably right,and the other problem is that we're having fun, and that's against the rules.
Glen

My definition of a Puritan is someone who loses sleep worrying that someone, somewhere, is having a good time.....

>Probably right,and the other problem is that we're having
>fun, and that's against the rules.
>Glen

Glen:

You don't understand...The neighbor Kelvin and I are talking about IS a chainsaw, weed eater and leaf blower combined and on two legs. And you should hear hubby!