stangman67

My Feedback: (1)

Anyone done a decibel test on a dle30 with the stock muffler?? My club has a noise limit and I need to decide whether I need to get a pitts muffler or not.

Thanks,
Zach

Jake Ruddy

My Feedback: (40)

I would bet you will probably need a pitts muffler. I haven't played with one myself but in most cases even a good side dump is loud.

Also keep in mind that prop noise has a lot to do with it. A high quality prop (pref CF) will go a long way. Maybe even go up a size to help with noise.

Jerry_Hailey

95db or louder if you have a loud prop.

Go ahead and get the pitts and look at a good prop. Mejzlik or Xoar

Jtec has a nice muffler. it works

stangman67

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The noise limit at my park is 90db, not sure at what distance but it should give you guys a general area to help me out

ggraham500

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You need to give more specifics. What distance from the running engine? In most areas it is around 9 meters away in others it is at the end of the taxi area, other clubs different. There is no set AMA suggestions or guidelines. Every time I check the ambient noise level for example in our rural club, it is around 55-65dB. With a Zenoah 23cc gas engine flying at close to max rpm in the air at approximately 60 feet, the dB level was around 73dB. What is your club's max and at what parameters?

stangman67

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Thanks, I was looking at getting the Jtec wrap around.

stangman67

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Graham, I posted the limit right before you posted, it is 90db and I am not sure at what distance. I bet its a couple meters.

Jerry_Hailey

Our club mesures the method from the AMA scale contest rule book. 25 feet in line with the prop and 24 inches from the ground. Also you will need a wind screen.

No way will the stock exhaust (note i did not say muffler) will get you below 90db.

stangman67

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Noted, Jtec just ordered from Chief

Jerry_Hailey

What took so long? [sm=spinnyeyes.gif] you posted the question over 10 minuets ago LOL

This was a fast thread

spaceworm

Some at our club have gone to three bladed CF props to reduce the noise footprint for their large gassers. I can't advise what size for the DLE30 though. Good luck.

stangman67

My Feedback: (1)

It's going on a wildhare "baby" edge. I have a 19 by 8 wildhare prop so I will try that out first and if the prop is too loud I will go to a Mejzlik (which are beyond sexy looking!)

nonstoprc

My Feedback: (90)

You may consider add something like Syssa 180 engine's tone inserts to cut the noise level even more. http://www.syssaaircraft.com/cart/pc...&idcategory=11

Jerry_Hailey

That engine very well with a mejzlik 18-8 two blade, so it should be fine with a Mejzlik 16-11 three blade.

i have not run that prop, so if anyone has, please post.

PlaneKrazee

My Feedback: (14)

The large volume JTec is a good choice, or if weight isn't a huge factor the Jtec dual snuffler is extremely quiet and doesn't seem to hurt rpm.

stangman67

My Feedback: (1)

Weight isn't a really big factor but as always I would rather not add extra weight if I didn't have to. I'll see how the wrap around works and then go from there. I'm sure it will be just fine. This plane is getting EXPENSIVE (although you 100 and 150cc guys probably think its chump change)

Tired Old Man

My Feedback: (1)

Dpllars are dollars Not too many glow engines making that 90dB limit without a lot of help.

jedijody

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DLE30 with stock exhaust and Xoar 19x8 laminated prop = 95db using AMA contest guidelines.

stangman67

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Thanks Jody, I probably could have gotten away with the stock muffler but I like the dual outlets of the jtec anyways. It should quiet it down under 90db for sure.

JOHNS3D

My Feedback: (5)

Zach, here is a video that maybe can help you.

[youtube]http://www.youtube.com/watch?v=PfKK69ACvt4[/youtube]

stangman67

My Feedback: (1)

Thanks, yea I saw that video, hard to tell much from it other than that it idles lower with the pitts and doesn't quite have the same RPM at WOT. The power loss won't matter since its going on a 10 pounder anyways

loser

My Feedback: (37)

I wouldn't be so sure. Theres a big difference between 90 and 95 db. Sound is measured on a logarithmic scale and I think sound pressure (noise) doubles with approx every 3-4 db increase.

Steve

RTK

My Feedback: (1)

A dle30 turning a 19x8 xoar on a stock muffler seems to be a little less noisy than most 60 sized glow engines that I fly with.
My flying style is usually at or less than 1/2 throttle. When I put on an 18x6 for more aggressive 3D flying the engine gets a little noisy, but not what I would consider loud.