Pilottonny
Well Known Member
Hello,
I have finally finished my FWF installation. Now see what is sticking out of the belly :
After searching the forums, I am more confused than before! I have Vetterman exhausts with mufflers and am wondering if it is worth cutting them off shorter!.
To me it is a very complicated issue:
I have seen some planes that have 1/2" holes drilled in the last 6-8" of the exhaust pipe, sort of like you see on automatic guns in cartoons. Do they attribute in noise reduction?
An other thing that I have seen is that the end of the pipes are squeezed close, and holes drilled in the sides and bottom, allowing the exhaust gasses only to escape through the holes. This could well cause noice reduction, but what about additional drag and reduced power due to back pressure?
If you think I should cut it shorter, what do you think is the best CUT in the above picture:
Regards, Tonny.
I have finally finished my FWF installation. Now see what is sticking out of the belly :
After searching the forums, I am more confused than before! I have Vetterman exhausts with mufflers and am wondering if it is worth cutting them off shorter!.
To me it is a very complicated issue:
- Over here (Europe), noise (heard from the ground) is a very important issue, because we have severe noise restrictions. For example, in Germany there is Airfields that charge up to 3 or even 4 times the landing charges for the most noisy aircraft. At some airfields you are not even allowed to take off at certain times of day, if you do not have a noice certificate of a certain (low) grade!
- Extra noise inside the cabin is annoying, but I have the CAD insulated carpets, so I guess shortening the pipes will not be to much of an issue in that respect.
- Weight savings is always nice, so the more I cut, the more weight I save, right?
- Less stuff hanging in the breeze is more speed, so the more I cut the faster I go, right?
- The closer the exhaust is to the belly, the dirtier the belly will get, right?
I have seen some planes that have 1/2" holes drilled in the last 6-8" of the exhaust pipe, sort of like you see on automatic guns in cartoons. Do they attribute in noise reduction?
An other thing that I have seen is that the end of the pipes are squeezed close, and holes drilled in the sides and bottom, allowing the exhaust gasses only to escape through the holes. This could well cause noice reduction, but what about additional drag and reduced power due to back pressure?
If you think I should cut it shorter, what do you think is the best CUT in the above picture:
- Yellow
- Blue
- Purple
- Other (please specify)
Regards, Tonny.
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