Why no tuned expansion chamber exhaust pipes for helis?

[JimLerch]

I see tuned pipes for off road rc vehicles, I've seen a few rc planks with tuned pipes, but why not any on a Heli?

Seems like an easy way to make more power... Is there something magic about a heli's constant speed that makes a tuned pipe non desirable?

[CoronaL]

they used too, but I think in general the pipes now are tuned, they just look more like mufflers. Hatori for instance. MP's are not so much. This is what I've read, I could of course be wrong!

[archiebald]

Just my opinion but since the trend in helis is mainly towards 3D where you can easily bog the head in some moves, it would be more troublesome to have a pipe tuned for peak power and you might find yourself falling out of the power band. You want a broader spread of power.

On top of that the trend is towards bigger engines in smaller airframes e.g. 30 -->32 -->37 -->46-->50-->53 and 60-->70-->90 all in the same frames. So the helis are grossly overpowered anyhow, a peaky tuned pipe becomes more of a liability.

For example, an old V8 muscle car needs very little tuning work done on the exhaust system to give oodles of power. (shame they could never go round corners though :YeaBaby:

[bigcat1]

The Curtise musle pipe is a tuned pipe.In my opinon pipes are better for 3d because they dont bog down as easy and they recover faster after bogging down.Just my 2 cents.