Return-Path: Received: from [144.54.3.31] (account ) by logan.com (CommuniGate Pro WebUser 4.0b1) with HTTP id 1230923 for ; Mon, 06 May 2002 14:34:42 -0400 From: "Marvin Kaye" Subject: Re: [LML] FADEC questions To: lml X-Mailer: CommuniGate Pro Web Mailer v.4.0b1 Date: Mon, 06 May 2002 14:34:42 -0400 Message-ID: In-Reply-To: <005101c1f527$e7969660$2c05000a@shannon> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "Shannon Knoepflein" : I am in the process of making the same decision. I'm building a L2K, and have opted for the IO-550 engine. I was looking into FADEC very seriously, and have been trying to do research in the last few weeks. Lancair doesn't know much except that it is running, but not enough to know any details. They had trouble getting it going though on Bob's 550, but have it running now. In my search, I have found another system called PRISM. It is made by GAMI (www.gami.com). The PRISM system, combined with totally balance GAMI injectors should allow a person to run their engine in the LOP region with great results (less fuel, same EGT's, lower CHT, cleaner burn, etc, etc...while still staying well out of the detonation region). From an engineering standpoint (I am an engineer, so that's how I tend to look at things) the PRISM system looks to be well thought out. From my initial understanding of PRISM vs. FADEC, instead of looking at EGT's (fadec, an indication of the trend of the last few engine cycles), the prism system looks directly at the combustion event by means of combustion pressure and looks where the peak occurs to adjust timing, as well as looking for 5kHz "knock" ripples after the peak. This seems like a dream come true system if it truly works. Again, this is just my understanding of the systems, and I am still learning, so if anyone can correct me or add any light to this area I would appreciate it. Last note, on www.gami.com under articles, there are a VERY informative set of articles written by John Deaken. --- Shannon Knoepflein <---> kycshann@kyol.net [ http://www.gami.com/prismtxtonly.html http://rob.com/lancair/2002.SnF/P4122872.jpg contains a very powerful knock sensor (well, optical peak pressure sensor) and actively adjusts timing to avoid detonation. very useful if you have a turbo/blower and wanta run LOP. http://www.fadec.com http://rob.com/lancair/2002.SnF/P4122884.jpg http://rob.com/lancair/Others/shannon/Lancair_Fastbuild/DSC00062.jpg http://lancair.net/Lists/lml/Message/3192.html maps the hole motor, adjusting both timing and mixture to actively find best power.. (or best economy, if you ever wanted go slow mode). very useful for lowering pilot workload, and maximizing your speed. I'm an ex-fadec depositor, as the system wasn't ready when I was. Do look in the archives, there are some good posts by George debuffing me :-) -Rob ]