zachattack2795

My duratrax st wit hthe velocity .17 is excessively loud. i put a piece of tubing on the exhaust to quiet it and it worked quite well. Just wondering if theres another way. I can live with some performance loss.

PrjctStrtFrce

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Not to sound like a smart azz, but you may as well convert to electric/brushless. I had a Velocity 15 and that thing was nearly silent compared to the big block motors I have now.

Just a thought.

proanti1

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I quieted down an HPI by shoving some brillow pad down into the muffler, made it almost silent. Not too much performance loss either because the pipe was already pretty far from being tuned. It was that really course copper brillow stuff.

zachattack2795

I'll try the brillow. I put some tubing on the end that quieted it a bit. I already have an electric truck. I like being able to choose what i want to drive.

dug44

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There sure is... Don't use brillo. The soap on it will oxidize your exhaust... Instead use a course steel wool. Take ( a small bouncy ball size)and turn it in your fingers to form a bullet like shape, and start feeding that bad boy in... It will quiet that bad oscar right down...

zachattack2795

thanks elaborating. ill pick up some steel wool tommorow

dug44

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You bet.

zachattack2795

I just took apart my two piece pipe and removed the baffle and stuffed the whole thing loosely with steel wool. I can tell if its slowed down or if its just from the sound but its significantly quieter and definately worth it for me. I also have my aluminum pipe for when i need to kick some *****

dug44

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Took it apart? how you mean?

proanti1

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I wasnt talking about the stuff with the soap, its comes in packs of 3... at least at my store, its like steel wool but copper. I wouldn't use steel wool, it would rust within days, then make a mess out of the inside of your pipe. Nitro oxidizes steel faster than hell, especially a soft steel like steel wool.

zachattack2795

i got the 3 pack of steel wool(stainless if it makes a difference) http://www.rc-hobbies.co.uk/images/PROTunedMuffler.JPG theres a picture of the muffler i used from a friends cheap japanese car. Will stainless steel still rust?

proanti1

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Nope, stainless wont rust.

zachattack2795

thanks for the peace of mind. i almost bought copper but i wasnt sure of it

dug44

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oh my bad man, wasnt doubting you. just wanted to make sure he didnt throw the ol' brillo from under the sink in there....

TTMT

So glad to find this thread. I drive an XTM truggy and an MGT 8.0. Both are very noisy, particularly the MGT. What about stuffing the exhaust pipe with fiberglass? That's what they use in certain full scale mufflers (e.g., Cherry Bomb glass packs). Is the power loss drastic or just slight? Seems like fiberglass would be safest because it wouldn't rust and wouldn't react with the aluminum pipe. Doesn't the galvanic reactionbetween steel andaluminum and copper and aluminum posea problem long-term?

proanti1

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RC car mufflers are designed quite differently than car mufflers. Dry gasses pass through a car muffler, so there is nothing to soak into the fiberglass. An rc car engine passes oil through the exhaust, enough oil to soak into fiberglass and make a mess.

TTMT

Makes sense. What about the galvanic reaction between the metals? Is it an issue? Do you need to replace the steel wool after awhile due to oily gunk build-up?

proanti1

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The mufflers I packed have been either hard anodized or plastic... so I have not had any issue with any sort of reaction. I have never really had the stuff in the muffler for longer than about a week at a time... so it never gummed up. I imagine it would get pretty gross after a few months though. The aluminum is so thick that any reactions would be too small to do the pipe damage.

TTMT

Well, if it's really effective and not hard to do, I'd like to try it.  How do you go about putting it into and removing it from the pipe?

proanti1

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I just shoved it in there with a screwdriver, and used a pair of needle nose pliers to pull it out.

TTMT

Okay, I may try it out at some point.  Thanks.

fyrstormer

I'm probably the only person who still cares about this topic, but I settled on bronze wool from an art-supply store instead of any type of steel wool, because bronze wool won't corrode the way steel wool does. (yes, even stainless steel wool will corrode from the nitric acid fumes in nitro exhaust.) There is a performance reduction, but if it's a choice between reduced performance vs. not being able to run your nitros because of noise complaints, then reduced performance is obviously the better choice.

Iflymostlyelectric

Honestly, I don't particularly know. As far as I can tell, no. I have a OS LA .46 nitro engine on an RC airplane, and it sounds pretty quiet compared to others, but the only way I think you can qiuet it down is with a tuned muffler.

1QwkSport2.5r

Tuned mufflers are often louder than basic mufflers are. Car engines are hard to quiet down because of their robust timing and often higher nitro content fuels. The nitro makes the exhaust note significantly sharper.

Basic sport airplane engines such as the OS LA and FP series are very low timed engines - anyone on the planet can operate them, and they’re not suitable to compare against a truck engine as mentioned in the beginning of my post.

Granted, this is an old thread that has been discussed at great length in the past, but blocking the pipe with foreign material is asking for trouble. Not only in respect to the pressure wave resonance (tuning) of the pipe, but also the fact that small fragments can dislodge and get pushed into the engine. There are ways of quieting an engines noise down, but it often comes with adverse consequences.