Netters.I have been discussing the EFI with Ron Slender the owner of VW Engines Australia, His comments may be of interest to some, it is long!!!!!!
Phillip, The comments made regarding fuel injection and the experience that some writers had are consistent to using a system in an auto. This may appear to be a cheaper solution it is fraught with possible problems in respect of sensors not required, altitude compensation, timing overall not to mention temperature operated at. RG are world leaders in providing EFI management for experimental aviation use. Demonstrated by our very successful RG TT 2200 and now the RG TT 2000 EFI. Our EFI runs on 2.5 Bar pressure............not 75 psi indicated. The computer controls the fuel pump and unlike an auto mechanical pump will keep on pumping as long as the engine is running. The RG engines run on MAP sensor, and head temperature for initial start enrichment. The engine is automatically leaned off according to map sensor at altitude. The computer also runs the ignition through an igniter and dual output coils. Advance and retard are controlled by the computer and the spark generated is better than a magneto could ever think about delivering through iridium spark plugs. Because the fuel map was done under a huge verity of load conditions the computer has been taught to deliver fuel and ignition according to those load demands. Optimum power delivery by precise fuel management and ignition that is what EFI is all about. Setting up for EFI properly is not cheap. You have to have a dyno to map in the engine. On air-cooled it is even more difficult because of the cooling required and the control of temperature because a tuned engine runs best at the temperature it was tuned at. Because it is easier to mount the engine in a car and to provide the cooling to it still a specially prepared car was needed to tune and map in the engine under a lot of various load conditions including acceleration rate under different loads. More expense. Not to mention the dyno time cost, fuel, long hours with highly technical personnel. One may THINK you can map in a EFI with the propeller because you are applying a load. In theory, but for that one propeller only, and at that pitch only. Change the pitch you will require a different tune. The wiring loom is a requirement so that guys cannot mess with it. Most of the aftermarket EFI specialists will tell you amateur EFI wiring almost in all cases has to be redone. That is why we include the loom ready made and tested with the engine so that this level of expertise is done to a very high standard complete with high quality terminals and crimping methods. To do all this for 1 engine is not practical unless it is a labour of love and determination to have FEI on an engine. That is why are engines are built as close as we can to the same specs so that the original tune is right for the engine. We have come a lot further now with the fact that if necessary you can data log your flight with a memory card or lap top. You can send us the data and we can make incremental changes if necessary and em mail a new program. You can have an on board 0 2 sensor but this doesn't control but reads only. You can read extra temperatures and what is really good with the new laws regarding the security of your aircraft you can unplug your computer, take it home, and NO ONE can fly your plane. Downside.......cost, yes more expensive, no carb heat, more torque and power. Some of you may say that if this fails or that fails but the same can apply to any engine and on any component. When you boil it down to reality there is always the possibility of a single point failure that will stop the engine or any engine for that matter. I keep a couple of certified engine crankshafts on hand for that reason. They say that those engines are reliable.....yes but I have 2 cranks that are cracked. When did they crack? Did they do it between pull downs? What would have happened if it had broken before the rebuild? Don't know really, but if it had broken in flight or just when you are up 100 ft it would have certainly stopped BOTH magnetos and stopped the pistons going sideways. This is experimental aviation guys where we can develop our ideas and put them into a new level of experience and the rules are to fly where you can land if necessary. Most that do abide by those rules are still alive to tell what happened. EFI..............has to be the way to go because the components are more and more reliable at 2005 manufacturing level. Our engine.........the 2000 and 2200 EFI aircooled gear drive. Currently the pick of the engines for the Typhoon and Cyclone aircraft. The choice of many aircraft builders including KR2, Europa, Sonex, Boomerang, XL Price of the engines are not as expensive as most 100 hp engines on the market and certainly more economical to maintain. Ron Slender Phillip Matheson mathe...@dodo.com.au Australia VH PKR See our engines and kits at. http://www.vw-engines.com/ http://www.homebuilt-aviation.com/ See my KR Construction web page at http://mywebpage.netscape.com/FlyingKRPhil/VHPKR.html Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
