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Old 10-16-2005, 10:48 AM
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bpryor
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Default RE: Extreme Flight 87" Yak 54 - Build & Fly


ORIGINAL: TailTouch

Here are the RPM figures from yesterday...

DA-50 with tuned pipe. 4 gallons thru it still using lawnboy ashless...

Mejlick 23x8 prop
6700 RPM
Hi TailTouch,

First, I'm not posting this to put down your numbers, only to maybe point out that you may need to look at your setup for something that isn't quite right....and I'm only posting the HP and thrust numbers below for comparison purposes and not absolutes.

Your numbers are actually below what I'd expect on a DA-50 with the stock Pitts-style muffler with that prop. What pipe are you using? I would expect the revs with that prop with a tuned pipe to be at least in the 72-7300 RPM range (5.5HP - 34 lbs thrust). A couple of DAs I've tached are both turning 22X8 Mejzlik's at 7600+ with stock mufflers(5.2HP - 31.8lbs thrust). I've seen many people post similar numbers to these online too. You can search this thread alone to support these numbers.

I'll tell you one thing, it's refreshing to see someone post numbers I'd consider to be on the low side, rather than some of the numbers I see that seem a bit optimistic.