The problem is that nothing is free. One could certainly use a venturi on or in the exhaust stream, but doing so is a restriction in the exhaust, which would inhibit exhaust flow and impact engine performance. I can't estimate how much or whether it would even be noticeable. I suspect someone with more expertise than me in exhaust tuning or an engineer with fluid dynamics software might be able to give a rough estimate.
I suspect the answer is that back in the 30s and 40s when gyros and venturis were first used, it was likely discovered that the impact to the engine performance was more than the impact of drag of the venturi on the plane. However, the planes of that day were much slower and draggier than our KRs, so that explanation may not hold water for our application. One thing I try to keep in mind when these ideas come up is that there are over 100 years of aviators and aviation engineers that have proceeded us, many of whom were quite ingenious. If they didn't do it, you need to look for the reasons why. This isn't the first time I've heard this idea floated, but I've never seen it in use. Doesn't mean it can't work, but makes me question why we haven't seen it before. Jeff Scott Los Alamos, NM -- Darren Crompton <kr.2s.dar...@gmail.com> wrote: Maybe I have drunk too much coffee today, but is there anything to stop one from running a vacuum line off the exhaust? -- Darren Crompton AUSTRALIA ____________________________________________________________ Switch to the thrill of high speed internet for $19.95/mo with AT&T http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTEs5NQSKAFStd0hl8TNPQiWCsJ1uXQFNab7YIxOjvHO1wYdcYp2Vd/
