|
|
John,
I have been planning a Vortech supercharger for my Renesis RV10 project. The plan was to run 4-5#'s of boost to bring the Renesis up to 250-260 hp. However after talking to several engine builders most (3 out of 4) advised against boosting the Renesis. Most believe the Renesis apex seals would not handle even this low amount of boost. So.... I am now looking at an Eaton supercharger that has a buildin bypass gate like a turbo. It believe this is the same SS the Egg Subi folks are running. They have a controller that keep the MAP at 31" all the time in the lower powered engines. Not sure if the controller is an off the shelf item or something they are having made. My current plan is to run the Eaton unit with a manual control cable to the bypass gate and use it for normalization of MAP not boost. I have a problem with the Renesis. It is to light for the 10 and Fred at Conversion Concepts is working with me on a longer mount to move the engine out several inchs. Hopefully lower compression rotors will be available for the Renesis soon. Or better yet.. a 3 rotor based on the Renesis. Oh ... did I mention I will need a custom cowl......
Bobby Hughes
________________________________
From: Rotary motors in aircraft on behalf of rv-7a
Sent: Sun 4/24/2005 4:54 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Upper Airspeed Data on Rotary-Powered Van's RV
I've been lurking the flyrotary list on occasion for the last year. I plan to hang a Renesis w/Tracy's RD-1C on my under construction RV-7A. My questions: 1) Has anyone flown an RV with a super or turbo charged rotary/RD-1C combination? If yes, I'd like to know how much flight data is available - specifically upper airspeed under what flight and aircraft conditions (fairings on? prop diameter/pitch/model/type? RV model? ...).
2) For anyone flying a normally aspirated rotary with the RD-1C on a Van's RV. If you've tested the upper airspeed of your aircraft in cruise flight would you be willing to share your data with me? Background:
The reason for this inquiry is that I naively planned to supercharge the Renesis installation because I thought the airframe could SAFELY cruise up to 200 KTS IAS (RV-7 Vne) in smooth air. At my typical NM altitude (12,500 MSL), that would be 248 KTS TAS (285 MPH)! However, my bubble was busted by the Van's RVAtor article on flutter (6th issue 2004). Van's engineers instructed their readership on flutter - that Vne is really a TAS limit, not an IAS limit. A US Air Force pilot and RV commuter corroborated the Van's article by telling his disturbing TAS flutter story (first 2005 RVAtor issue). If you haven't read this, I recommend it for all pilots, no matter what they fly.
I've decided to follow Van's advice and restrict my upper airspeed to limit to 200 KTS TAS in smooth air. I don't want to be a test pilot. Therefore, I'm reconsidering my plan to supercharge the Renesis/RD-1C installation. The weight penalty may not be worth climb performance increase if 200 KTS TAS cruise can be easily achieved with a normally aspirated installation. If I can collect empirical data from RV Rotary flyers, it would sure help my decision.
Thanks,
John Burns
rv-7a@comcast.net
http://mywebpages.comcast.net/jgburns/Engine/Engine.html <http://mywebpages.comcast.net/jgburns/Engine/Engine.html> for my engine webpage.
|
|