diabloblanco

I have a SuperTigre .40(ringed), the factory exhuast is 2 piece, manifold and muffler. My question is can I extend the manifold and remove the muffler entirely without drastically decreasing power. I understand the importance of pipes on 2 stroke motorcycles but I dont think that applies so much here.

Phlip

You can, and the power will likely increase, that is after you retune your needles to get proper fuel flow without the muffler pressure to the tank.

Big problem, though, will be NOISE!

Charlie P.

You'll want the exhaust opening still constricted some unless you run a very long manifold. The engines are ported for some exhaust resistance and I don't know if you'll be able to just eliminate it entirely. And without a tank tap you won't get much fuel flow unless you add a pump. I think you'll find you'll over-lean and konk out in upward flight.

bipeguy03

Your biggest problum will be the noise. Must clubs will not allow you to run an engine without a muffler and if you have your own place expect to get phone calls from the neighbors. these little engines get LOUD with out an exuast.

On another note, Charlie p is exactly right, with out a fuel pump it will be very hard to get fuel to the engine. without the proper back pressure generated by a muffler your tank will not be pressurized, and a carb that small does not have the ability to draw the needed amount of fuel from the tank.

If you are wondering about this becuase you have a cowled engine, I would look into a Bisson muffler, they are kinda like Flowmasters for R/C. you can get alittle bit of a preformance advantage over stock, but it will keep it quiet and it has it's own sound.

diabloblanco

Thanks for the replies, I am going run the muffler for the time being but if this model flies well Ill look into the Bisson. Unfortunately I had to hack up the cowl to make everything fit. This my first nitro and my first ARF so Ive decided to keep it basic for now. Would this .40 without a muffler be louder then one of the ~100cc gas engines making a speed pass?

Phlip

Maybe not, but it would be all the time ... even the idle would be noisy. The noisiest thing about the large scale planes, and why it happens particularly during a speed pass, is the prop. At high speeds the prop tips approach the speed of sound and cause shock waves. That's where the big noise is coming from, not from the engine.

The other thing about the sound of model airplanes that annoys non-participants and turns them into complainers is the whiny-ness. And when you get it up into the air, the sound travels for a great distance as there is nothing to stop the sound waves but the wind.

If you were going to run this engine without a muffler, I would reccomend ear plugs or muffs for especially when you tune the high speed needle.

Phil