201er Posted January 30, 2012 Report Posted January 30, 2012 I was surprised to learn that a bunch of guys have never even once opened their ram air. So I wonder what proportion of Mooney pilots use the ram air or not and their reasonining. Be sure to state what kind of Mooney in discussion and how much impact the ram air has. Quote
Ron McBride Posted January 30, 2012 Report Posted January 30, 2012 In my 69F I use it at altitude, above 5000. I get a full inch out of it. Ron Quote
smccray Posted January 30, 2012 Report Posted January 30, 2012 I've opened the ram air at altitude but doesn't seem to make any difference. If there is a difference I don't see it on the MP gauge. Quote
aerobat95 Posted January 30, 2012 Report Posted January 30, 2012 Quote: N9154V In my 69F I use it at altitude, above 5000. I get a full inch out of it. Ron Quote
Immelman Posted January 31, 2012 Report Posted January 31, 2012 My understanding is that the J's induction system was well-designed enough that it didn't matter. The E's and F's on the other hand... it makes a substantial difference. If the air is clean and I'm not going through visible moisture the ram air is coming on with my after-takeoff checklist and staying on until I start backing the power back in descent. Quote
flight2000 Posted January 31, 2012 Report Posted January 31, 2012 I use it above 5,000 feet in clean air. I usually see about an inch increase in Manifold pressure as well. Brian Quote
Vref Posted January 31, 2012 Report Posted January 31, 2012 Nope, disabled and covered on my J last one should be My mooney doesn't have it anymore... Quote
Shadrach Posted January 31, 2012 Report Posted January 31, 2012 I use it whenever in clean air. Down low I get >1" of mp in my 67 F. If I'm LOP, opening the ram air will actually drop EGTs ~20df when below 5000ft. Quote
Gone Posted January 31, 2012 Report Posted January 31, 2012 Quote: flight2000 I use it above 5,000 feet in clean air. I usually see about an inch increase in Manifold pressure as well. Brian Quote
jax88 Posted January 31, 2012 Report Posted January 31, 2012 I have opened it a handful of times above 10,000ft, but I only notice just less than an inch of manifold pressure increase. Quote
Shadrach Posted January 31, 2012 Report Posted January 31, 2012 Quote: jax88 I have opened it a handful of times above 10,000ft, but I only notice just less than an inch of manifold pressure increase. Quote
Piloto Posted January 31, 2012 Report Posted January 31, 2012 On the M20J models the only time you will see some significant difference (1/2") is when your IAS is above 140kts. So above 10,000 ft is hard to see any difference. The RAM air differential pressure is in direct proportion to your indicated airspeed. Any significant advantage would be below 5,000 ft at full throttle. José Quote
BlueSkyTraveler Posted January 31, 2012 Report Posted January 31, 2012 In my '67 F model i use it above seven grand ---- or higher if i still get bug splatter on the windshield up at 7,000------ what are those insects doing that high anyway???? Does anyone else consider that or just go for it????? Quote
Bennett Posted January 31, 2012 Report Posted January 31, 2012 I have the LoPresti cowl on my M20J, and I regulary use the ram air above 5000' when the air looks clean. I get between .8 and 1.0 " increase in MP with the ram air fully open. The LoPresti ram air is quite different from the stock cowling. You can see this on their website and video. Nice cowl, but expensive. Quote
drapo Posted January 31, 2012 Report Posted January 31, 2012 Quote: edgargravel Me too. On an E model. Quote
KSMooniac Posted January 31, 2012 Report Posted January 31, 2012 It was next-to-worthless on my J, and I removed the system. (there is a thread on the Misc board about this right now). Quote
Shadrach Posted January 31, 2012 Report Posted January 31, 2012 Quote: Bennett I have the LoPresti cowl on my M20J, and I regulary use the ram air above 5000' when the air looks clean. I get between .8 and 1.0 " increase in MP with the ram air fully open. The LoPresti ram air is quite different from the stock cowling. You can see this on their website and video. Nice cowl, but expensive. Quote
jetdriven Posted January 31, 2012 Report Posted January 31, 2012 the J is too, the inlet for the ram air goes straight through the fuel injector servo. the reason I heard there is not much MP gain with ram air on the J is the induction plenum is much more efficient, IE, less "loss" in the duct. Quote
meddesign Posted January 31, 2012 Report Posted January 31, 2012 yes at altitude at full throttle 7.5k or higher pick up an inch MP Quote
DrBill Posted January 31, 2012 Report Posted January 31, 2012 Yes over 4000. When I remember it. 65 E BILL Quote
Shadrach Posted January 31, 2012 Report Posted January 31, 2012 Quote: jetdriven the J is too, the inlet for the ram air goes straight through the fuel injector servo. the reason I heard there is not much MP gain with ram air on the J is the induction plenum is much more efficient, IE, less "loss" in the duct. Quote
jetdriven Posted January 31, 2012 Report Posted January 31, 2012 I have seen 29" perhaps 29.5" of MP at 1000' before. the altimeter setting was 30.25. I'd like to see as well. Quote
201er Posted January 31, 2012 Author Report Posted January 31, 2012 Meanwhile the 201 POH claims greater than ambient pressure at various altitudes under standard conditions! Quote
M016576 Posted February 1, 2012 Report Posted February 1, 2012 I use ram air in my J more as an indicator for when to clean out my air filter or replace the element. Any gains over .4 or so at altitude and I know it's dirty.... Quote
DaV8or Posted February 3, 2012 Report Posted February 3, 2012 I used to use mine all the time, but have stopped because of concern for my induction boot. It's a glued up repaired one and my theory is that air going through the filter is easier on it. As soon as Mooney, or anyone else gets around to making me a new one, I'll go back to using it again above about 5k feet. It does help. I love the Lo Presti cowl and really like the ram air valve they use. Wish I could just get the valve and retrofit my SWTA cowl with it... or Lo Presti just reasonably price their cowl kit. Quote
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