Greg,
I installed a temporary door seal. I need to get the inflatable seal ordered and installed. That should make a big difference.
No, I initially was going to turbo, but changed my mind. I figured that I could always add it later. Which make/model turbo are you using? The turbo will definitely help with the exhaust noise.
Sound proofing came from ACS. I ordered a variety of thicknesses from 1/4" to 3/4". The thicker stuff was used under the floorboards and on firewall. It really isn't very heavy for the comfort it provides. The rotary's exhaust tone, as heard through the ANR headset, is very similar to an outboard motor. Now imagine listening to the drone of an outboard motor for hour after hour. If you don't do it for yourself, do it for your pax.
Mark
On 3/30/08, Greg Ward <gregw@onestopdesign.biz> wrote:
Hey Mark;
Thanks for the positive report on the 20B. I am hopefully within about 3-4 weeks of doing my static run-ups. Waiting for the ECU, the prop, and the welder, then it's light-it time. Are you turboed? I am doing the turbo, and the inflatable cockpit seal, it's on order, so I hope the noise will be tolerable, but if not, oh well. What are you using for sound proofing? I am at just the right stage to install something, but I don't want to add too much weight. Again, thanks for the input.
Greg Ward
Lancair 20B RG in progress
----- Original Message -----
Sent: Sunday, March 30, 2008 7:27 PM
Subject: [FlyRotary] Re: Request (for those already flying...)
Doug,
Well, I thought that someone with much more rotary experience than myself would respond, but I guess they're all out flying, or maybe they're on their way to SNF. So, I'll tell a little about my limited experience flying a 3-rotor Lancair ES. I currently have 33.9 hours on the airframe, and another 40 hours of ground running.
First thing you'll notice is that the engine starts with very little fuss. From my limited experience flying behind Lycosarus, when starting a Lycosarus, you are really wondering IF it will start, and you're always relieved that it does, especially if it is a hot start. When starting the rotary, I give it about 1/2" throttle, turn on the Main & Aux busses, the EC-2, the fuel pumps, injectors, prop, and EFIS. Finally, I turn mixture knob to full rich, touch the Program button once for a bit of primer (if it is a cold start) and hit the starter and she starts right now. After a few seconds of running, I start leaning little by little. No jerking and shaking, just the sweet purr of the rotary. The sound is much different, sorta like the difference between a tractor and a Ferrari. Not to be overly critical of the Lycoming, but the rotary is idling close to where the Lyco normally cruises.
Takeoffs are a real thrill if you're used to driving a family sedan. By that I mean that the normal operating rpm you see with a rotary are way above what most drivers will ever see in any family car. On my takeoff roll, I usually see around 7200-7300 for a second or two until the prop bites, then it drops down into the upper 6's, but I'm flying a C/S prop, so others experience may vary. Applying throttle slower helps to keep the R's below 7k. I'm used to flying behind 100hp, so when I pour the coal to the 20B, it is very exciting for this pilot. You feel every inch of throttle, even the last one. I'm accelerating down the runway and am off and climbing in a few seconds. I usually climb at about 105-110 kts (cruise speed for a 152) at around 1300 fpm. My biggest headache has been the exhaust noise. I just ordered a new Lightspeed headset and finished installing soundproofing material. I had measured the sound to be 105db in cruise. I'm sure it was more than that during climb. After installing the soundproofing mat, the sound level dropped down to 98db. Not exactly "quiet", but a big improvement. Once I get the rest of the upholstery installed, it should drop even more. So, pay attention to the exhaust system. Your ears will thank you.
Do people notice that you're flying a rotary? Absolutely! I have people tell me all the time that they heard me flying over their house on some particular day. The call me the flying chainsaw because the engine sounds like a chainsaw, at least to them. I'm not sure if that's a compliment or not. Anyway, it definitely has a different sound.
Its late, so I'll stop. Will try to add more later. Now come on Al, ED, Tracy, Dennis, Dave, etc. Let's hear your war stories.
Mark S.
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