---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Wed 07/04/07: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:11 PM - Gearbox Ratio change on Rotax 912UL (John Herbert) ________________________________ Message 1 _____________________________________ Time: 11:11:30 PM PST US From: "John Herbert" Subject: RotaxEngines-List: Gearbox Ratio change on Rotax 912UL Does anybody have any experience with the efects of changing the gearbox ratio on a Rotax 912UL from 2.27 to 2.43 ? I have been told, but wish to get more information on this subject, that to change the ratio to 2.43 will improve performance. I personally cannot see how this is possible as the propeller merely converts available engine power to thrust. The only difference that I can possibly see is that the slightly slower turning prop with the 2.43 ratio will have a slightly coarser pitch than it would have with the 2.27 ratio to get the same static full throttle RPM. This will possibly result in slightly better cruise speed at the same power setting, but in my mind the effect will be marginal. I am installing higher compresion pistons in a 912UL and am investigating the idea of changing the gearbox ratio to 2.43. Any ideas or comments would be welcome. John Herbert Tel: 0834634865 Fax: 0137500938 P O Box 879 White River 1240 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.