badger5964

My Feedback: (6)

I have a Slimline large volume pitts muffler with smoke chamber. It is mounted to a ST 3250. It is loud! I do not want to anger the neighbors or get the thing banned from club due to noise. Any one have suggestions to quiet this beast down?

Thanks
Scott

badger5964

My Feedback: (6)

Geez. Not even a opinion?

Motorboy

Use larger propeller diameter and less pitch.

anuthabubba

My Feedback: (102)

Try a truly 'large' volume canister/mousse can type muffler for less noise ... and ... a power boost.

Terry in LP

daveopam

My Feedback: (9)

I would also say try a different prop. If this is a sport plane you could run a 22x8 or 20x10 in the big Tigre.

David

Sport_Pilot

Try restricting the muffler outlets. They are much large than they need to be.

Jazzy

-Put neoprene or high temp hose exhaust extensions on the pipes
-stuff and pin-in some door screen mesh in the pipes
-larger prop
-cable tie in place some high temp tubing that is wrapped around the 'can' to reduce 'ringing'.

badger5964

My Feedback: (6)

Thank you for your replies.

This morning I went looking for something to pinch, plug or restrict the outlet. I found that a 1/4" brass pipe nipple threaded into the exhaust outlets answered the call. It got tighter as the pipe nipple threaded in due to the tapered thread.

Made two flights and the machine makes less noise and the pinging, sharp sound is gone. The noise sounds 'deader'. The nipples worked well, they stayed in place. Although quieter, I am still loud.

I have to give a thumbs down to this muffler. I bought it for the smoke coil built into the muffler. It adds heat to the oil and it did work well for producing smoke, I can produce it as fast as my Sullivan smoke pump can pump. Before starting second flight I test ran the smoke pump, wishing to confirm settings. The internal smoke oil connection was leaking terribly. Upon removal the o-ring that makes the seal was in crumbs, destroyed by heat, oil or glow fuel. I do not run nitro in the big tiger.

Well back to the shop to try another fix for noise problem plus find replacement or repair for the dripping heater coil. Does silicone stand up to MDW aviation smoke oil? Could I just put it in in place of the O-ring?

Has anyone had any experience with a Jtec RC snuffler? Looks like they just clamp on the exhast tubes. Much more money then I hoped. At $29 each this is getting steep. I already paid $120 for the muffler to begin with. Here is a link for the snuffler:
[link=http://www.jtecrc.com/snufflermufflers.htm]Jtec Snuffler[/link]

I think I'll try completley plugging one outlet, leaving the other stock. Next step would be to try one completly plugged and the other with 1/4" pipe nipple. Then perhaps the screen, canister muffler and silicone extension tubes.

Thanks for your input!

Scott

[link=http://www.fayettevillercclub.com]www.fayettevillercclub.com[/link]

daveopam

My Feedback: (9)

Scott, if you think the Pitts style you have is loud, it's nothing compared to the J-tec. The silicon extension tubes work well and are easy. They can get heavy. I bought some 1/2" thin brass tubeing from K&S one time. From Tower it came 4 of the 12" sections per box. I used the silicone as a coupler and ran a 24" pipe off of a stock ST 90 muffler. The difference in sound was major. As an added bonus the plane stayed a lot cleaner.

David