M20J Speed Mods?

[fantom]

....Next time flying, give it a shot.....Technique is a good speed mod as well

 

Count on it.....

[wishboneash]

That the typical descent profile for me, full throttle, 15 LOP in cruise (usually 9 GPH or so), and keep that power setting and FF all the way down, 180-200 MPH IAS, 750-1000 FPM descent until 3 miles from airport, usually gives a 175 knot groundspeed, sometimes up to 200 knots.  For a straight in, arrive at pattern altitude 6 miles from the runway.  For a midfield crosswind entry, 2-3 miles from airport center.  The key is a 2-3 mile level segment.  Level off, set the power to 17", and wait a minute, at 153 MPH gear down, you only have to lose 40-50 MPH IAS to get that. If you get short on distance, pull it up 200' to get the gear speed.  After the gear is down, it really slows down in a hurry.  Full flaps at the white arc. Next time flying, give it a shot.  That descent profile (along with the target EGT 123 KIAS climb) makes such an impact on the block time, you can often show a block speed of 150 knots, or you can fly to a destination 150 NM away in one hour.   Technique is a good speed mod as well

 

this is 188 KTAS or so. GS was 199 knots

IMG_2971.jpg

 

The Garmin 696 has a extended line depiction on the map based on time or distance. For example, one can set it to look at X miles ahead or Y mins ahead. This will work well at unfamiliar airports on when to get to this 2-3 mile level segment.

[Bennett]

The newest Foreflight on the iPad/iPad Mini has this feature - variable distance, or time rings, and a projection line for time or distance. .  I set my iPad Mini for distance (and the 796's projection line is set for 10 minutes time). Nice to have this information, especially close to the destination airport.  Also to pick an airport to change tanks over. (Awkward sentence, but you get the idea). Avionics just keep getting better and better, with useful information (that can be turned off, if you find it distracting). .  

[Skybrd]

I mentioned strong tailwinds at altitude, so ground speed yesterday (not TAS) was 190 Kts. The class Bravo rings around San Francisco airport require dropping below 8000' then 6000' and then 4000' VFR. I typically descend at about 450' per minute after scooting under the 8000' ring which gets me to about 3500' about 10 miles from the airport. We normally get a straight in to Rwy 30, so I have plenty if time to bleed off airspeed to drop the gear. Yesterday the tail winds continued (though diminishing) to about 1000'. TPA at KSQL. Is 800' with the airport at just above sea level. With the tailwind I was getting to my normal descent point for a straight in at 3 miles from the runway faster than normal, and a steeper descent was prudent, hence the deployment of speed brakes. Could I have done different things? Sure, but speed brakes made it real easy. Just another tool to use when it makes sense to do so Clever point about all 201 cowls being LoPresti cowls. I do like the ram air system on the aftermarket system, and the workmanship on mine is just fine. I recall that Paul at LASAR tested the PowerFlow exhaust system on a 201, and I called him this morning to ask if he still had the data. He said he didn't, but he said that both climb and level speed were improved. When Mod Works cut off my step in the 261, we tested the airplane before and after via averaging the four cardinal directions, and saw a two knot improvement in speed after removing the step. Of course, even at the same altitude, weather conditions could have been different. I sometimes slip off the step, so it won't be missed when I have it removed on the 201 It is hard to gain any significant speed improvements on the J, but the cumulative effects of all the mods I have give me a reasonable cruising speed, and I am happy with the mods.

Bennett, when you talked to Paul about the PowerFlow exhaust, did he mention the cabin heat problem. I have a Lopresti Cowl and Generation I PowerFlow exhaust and my cabin heat is almost non working. I was told that only generation 1 PFE would work since I had a Lopresti Cowl. I think the generation 2 PFE has a better cabin heat muff. You might want to check into this since you have the Lopresti cowl. If I ever get in some icing condition, it would be nice to have cabin heat, hopefully someday I can do something to get some heat. -- Darrell

[Bennett]

I have not tried to turn on the heat in the two and a half years I've owned this aircraft. Just to know, I will try it this weekend. Living in California has some advantages. Thanks for the heads up.

[M016576]

Very nice write-up Bennett, with just a couple of minor quibbles.

 

All 201 cowlings are LoPresti designs. The non OEM ones are expensive and of questionable quality as you point out, and you're lucky to have an early one. Per what Roy LoPresti told me, the only real speed improvement was the positioning, size and shape of the air intakes in the nose.

 

All data and reports I've seen claim negligible speed improvements for the PowerFlo hooked to a 201, especially the newer ones. Also model year of the 201 is important when discussing speed mods, since Mooney made incremental improvements as the 201 matured.

 

A friend with a 231 took detailed speed notes years ago, before and after removing his welded on step. He said the increase was 0.5 kts, under the best of circumstances, so I can't imagine a 2 kt increase. His wife also never forgave him!

 

Byron.....how the heck do you slow down in level cruise from 190 knots to gear and flap deployment speed in 2-3 miles? Come to think of it, how did you get to 190 knots to begin with?

 

Finally...what is Mike201er up to with these demanding requests?

Fantom- you flew rhino's, right? A couple loaded up 3-4g turns will take care of that excess energy in a flash!!!

[rbridges]

 

 

All data and reports I've seen claim negligible speed improvements for the PowerFlo hooked to a 201, especially the newer ones. Also model year of the 201 is important when discussing speed mods, since Mooney made incremental improvements as the 201 matured.

 

 

 

 

have you run across any data for older mooneys?  I have one on mine, and I'm curious how much benefit it adds.  I know some planes have restrictive factory exhausts, but I don't know if that's the case with the C models.

[fantom]

Fantom- you flew rhino's, right? A couple loaded up 3-4g turns will take care of that excess energy in a flash!!!

You just love those Air Force overhead breaks, don't you? They work for a Mooney also, but students, lackadaisical traffic and my tower usually don't permit it From the ground, or from the cockpit for that matter, a four ship echelon break over the runway is a sight to behold. I'll pass on any 4g turns in a Mooney however. Heck, some folks here want me to feel guilty for deploying my speed brakes every so often

[fantom]

have you run across any data for older mooneys? I have one on mine, and I'm curious how much benefit it adds. I know some planes have restrictive factory exhausts, but I don't know if that's the case with the C models.

No real data at hand but I've read that you can expect cooler temps, better fuel flow and a 4-7 knot improvement. Some people here should have better before and after comparisons for the C.

[Piloto]

Best speed improvement for the money is a good wax job. Many claim up to 5kts but personally the most I have seen is 3kts. Which for a $5 can of wax and some sweat is not bad and the plane looks good. Keep in mind that in order to see a noticeable speed improvement you have to fly at max power and low altitude. Any of these speed mods at high altitude at 50% power are a wash out.

 

José 

[Steve Dawson]

Bennett,

Do you have the older step without the aerodynamic fairing?

If memory serves a 4:1 fairing will decrease the drag by approximately 10 fold. A 1" tube has a drag cf of .4 and with the fairing it decreases to .04.

I've taken my step off and wanted to reinstal it however I'd want to put the fairing on the was installed on later models.

[KSMooniac]

I couldn't really detect any measurable improvement after deleting my un-faired fixed step either.  That was a disappointment.

 

I agree 100% about drag reduction and rigging being the first things to attack.  Cowl alignment/condition is important as well... a worn cowl that lifts up at the nose will be a lot draggier.  Paint condition and wax are worthwhile.  I would address all of those items before spending big money on mods.

[Bennett]

The step on my 261 that we removed was longer than the one on my 201, and it was not "faired" - just a tube, with a welded on tube for the actual step. This is the one that we tested before and and after, and while the tests were done on different days, we used the same altitude, and averaged four passes on the cardinal directions. Atmospheric conditions may have been a bit different, but we did get a solid 2 knot increase after the step was removed, and the hole covered with a metal fairing plate.  My 201 has an airfoil like section from the fuselage to the step, and the step itself is a sort of a flattened airfoil. So far I seem to hear that, in spite of my earlier experience with the 261, removing the 201 "faired" step is a waste of money.  Also, even if I occasionally slip off the step getting out, I think my shorter (female) passengers like the step.  Thanks for the input.  Steve, I'm impressed that the fairing would result in a 10 fold decrease in drag.  I still haven't found a good authoritative source to compare the towel rack vs blade VOR antennas on the vertical stabilizer.  Does anyone on the forum know? I hate the looks of the towel bars, but if they are less drag than the blades, I will "like" them better. Just a thought: when the tail moves, the blades will change their angle of incidence, and possibly increase drag. 

[KSMooniac]

The blades are definitely lower drag than the towel bars and cat whiskers.  Years ago I found that data on a vendor site that had values in lbs for drag at 250 knots IIRC, but I couldn't find it again a few months ago when I was searching.  The Bonanza crowd did some experimenting and found an optimum location for mounting them on the lower aft fuselage at an angle that paralleled the prevailing air flow around the V-tails for minimal drag.  A similar location could work for Mooneys and it would be much easier than a retrofit on the vertical stab, but I'm not sure I like the aesthetics of it yet.    Out of sight in the wing tips is best IMO, but I don't have wing tips either.  So I continue to fly on with the ugly whiskers for now.... 

 

All of the jets and turboprops at work use the blade antennas FWIW.

[jetdriven]

The step on my 261 that we removed was longer than the one on my 201, and it was not "faired" - just a tube, with a welded on tube for the actual step. This is the one that we tested before and and after, and while the tests were done on different days, we used the same altitude, and averaged four passes on the cardinal directions. Atmospheric conditions may have been a bit different, but we did get a solid 2 knot increase after the step was removed, and the hole covered with a metal fairing plate.  My 201 has an airfoil like section from the fuselage to the step, and the step itself is a sort of a flattened airfoil. So far I seem to hear that, in spite of my earlier experience with the 261, removing the 201 "faired" step is a waste of money.  Also, even if I occasionally slip off the step getting out, I think my shorter (female) passengers like the step.  Thanks for the input.  Steve, I'm impressed that the fairing would result in a 10 fold decrease in drag.  I still haven't found a good authoritative source to compare the towel rack vs blade VOR antennas on the vertical stabilizer.  Does anyone on the forum know? I hate the looks of the towel bars, but if they are less drag than the blades, I will "like" them better. Just a thought: when the tail moves, the blades will change their angle of incidence, and possibly increase drag. 

My airplane came from the factory without the fixed step, I assume it was a marketing ploy on the 1977s.   I suspect if you mounted the blades on the vertical stab at the same incidence as the horizontal stab the drag would be lowest, the blades AOA matches that of the horizontal stab.

[Bennett]

I've seen some data for antennas using 250 Kts as the measurement point, but nothing about the towel bars at lower speeds.  It may not make much of a difference at 160 kts, but round sections generally have more drag than streamlined sections. The towel bars are rather small in cross section (but larger than the cat whiskers), and I really wish I could find some real world data.  I have the  factory fiberglass wingtips, whose forward sections are filled with LEDs, Taking off these wingtips, running the wiring, buying and mounting the blade antennas in the remaining sections of the wingtips, and then repainting the wing/wingtip junctures seems like way too much expense and hassle, unless there was a huge reduction in drag. I did this on my 261, before painting, and when I had more discretionary funds. I would have to guess that the costs would end up in the $5,000 - $6,000 range, and that would buy a lot of gas. A year ago or so I had dinner with an FAA official whose job assignment was to investigate eliminating VORs. I don't know that this will happen, but who knows what the FAA will do next. I would hate to see them go, as what other back-up do we have for GPS? I still use VORs in flight planing, and in fact, I set my GTN 650 to follow a VOR to VOR flight plan, "just in case". 

[201er]

Well there's an immediate trip time/cost savings for you right there... fly GPS direct and skip the VORs. Probably worth more than drag reduction of the VOR antennas

[Bennett]

I guess I wasn't clear here. The GTN 750 is set for whatever route I want - often GPS direct, but I do a separate flight plan, not coupled to anything, for the GTN 650, which is VOR to VOR, plus intersections defined by VORs. Its back-up, but also interesting to follow, and since most VOR to VOR routes are on Victor airways, the MEAs are easy to see, along with distances between VORs and intersections. Old fashioned, but it would work in the event of GPS failure or jamming. Sometimes I fly by really old fashioned pilotage, just for the hell of it. (and I still know to use my sextant when sailing offshore).

[jetdriven]

I've only seen two GPS failures, one while navigating through a MOA that just went hot, and two, flying near Mecca.  I suspect both were jammed.  Other than that it's always worked. However, I have had a whole host of electrical failures which at times didnt lend itself to long-term use of the GPS or the other boxes in the plane. For that, there's an iPad and as a backup to that, an iPhone 5.

 

I also find it amazing how willing controllers are willing to clear a M20P/A with a VFR GPS to the destination or the initial approach fix 400 miles away.  We always get there though.

[RobertE]

I've only seen two GPS failures, one while navigating through a MOA that just went hot, and two, flying near Mecca.  I suspect both were jammed.  Other than that it's always worked. However, I have had a whole host of electrical failures which at times didnt lend itself to long-term use of the GPS or the other boxes in the plane. For that, there's an iPad and as a backup to that, an iPhone 5.

 

I also find it amazing how willing controllers are willing to clear a M20P/A with a VFR GPS to the destination or the initial approach fix 400 miles away.  We always get there though.

Flying through Mecca? In Saudi Arabia? Do you have a great story to tell?

[jetdriven]

Nah we flew near it all the time going to Jeddah, But on 9-11-12, one of our crews flew right over it after Center missed giving them the handoff to approach. The Saudis completely flipped out on the crew and deported them, which is a pretty good punishment if you ask me.

[Jsavage3]

Have the aircraft rigged by one of the MSC experts - LASAR, Top Gun, Maxwell and a few others. 

 

I live in south/central Ohio and I'm looking for the nearest "expert" MSC -- any suggestions for me?  Thanks!

 

I have power-flow exhaust, GAMIs, ram-air option and K&N air filter -- gets me 158 KTAS at 9.3-to-9.7 gph running at peak (peak for first-to-peak).  Not bad, but if I can get this rigging straightened up, well, that ought to help...