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Cowling mod performance info


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It's been a long time coming for me to get some performance numbers for my cowling mod. Today I flew a performance flight in my modified C and took my numbers. Previous data had my airplane at 148 KTAS. Today's numbers put me at 154 KTAS. I'm pleased with the initial numbers and I plan to fly several more flights and take the data again to verify with more than one flight.

With this and the decrease of CHT's by an average of 25-30 degrees Fahrenheit, I think I have a pretty good mod. The STC package is going together and I'm hoping to submit it in a couple of months and get the certification process going.

David

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David - thank you! I am, like Matt and many others, following your progress on the mod. In fact, I'm holding off on doing a paint job until I see if your mod will be available for an F.

I know you posted some pre-paint photos. If you do paint it, I would love to see what the new cowl will look like.

Sent from my iPad using Tapatalk

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Hi Marauder,

I use all the original fasteners, although some are changed to a little longer lengths. I added 10 screws across the front to connect the upper and lower cowls. I retain much of the original cowling and structure.

Hi gsxrpilot, I'm not going to take deposits as the certification timeframe is a huge unknown. This can cause problems for people who have money out and nothing to show for it. I'll post updates as the STC progresses so anyone interested can keep track of progress.

Thank you,

David

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2 hours ago, Sabremech said:

It's been a long time coming for me to get some performance numbers for my cowling mod. Today I flew a performance flight in my modified C and took my numbers. Previous data had my airplane at 148 KTAS. Today's numbers put me at 154 KTAS. I'm pleased with the initial numbers and I plan to fly several more flights and take the data again to verify with more than one flight.

With this and the decrease of CHT's by an average of 25-30 degrees Fahrenheit, I think I have a pretty good mod. The STC package is going together and I'm hoping to submit it in a couple of months and get the certification process going.

David

If I remember correctly, you had the ARI cowl before you started the project.  Is your preliminary 6 knot increase the Delta from the ARI to your new cowl?  

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Hi Flyntgr1, 

Yes, I had the ARI enclosure to start with, so you are correct. Bob Kromer told me I'd see a good number. I'm going to do several more of the same test flights in the next few weeks to verify today's result.

Thank you,

David

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Hi Raptor05121,

The air filter is relocated to the left cooling air inlet. That's the reason for needing the 201 style spinner and backplate. That gives the room needed to locate the air filter in the front baffling.

I'm hesitant to give a price estimate yet as there's still a few unknown costs for parts. When I have those costs known, then I can give an estimate.

Thank you,

David

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Hi mike20papa,

 The performance flight was done at 6500 feet, 2500 rpm (using a prop tach), and full throttle. I don't have a fuel flow to measure the fuel burn and I didn't pay attention to EGT's on this flight.

 Hi Mike E, we have vacation on the calendar for the Summit and hope for good weather to fly!

 Thanks,

 David

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Just now, daver328 said:

Waiting for E, F and J owners to call you a liar ... Err ... Accuse you of Exaggerating your airspeed. It happens every time a C owner claims anything faster than 135. You had to have had a tailwind in all three/four directions!

Oh unfair. We're as anxious as you C owners are to get another 6 kts or more free speed. For my decrepit old E that would be about 164 kts.

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2 hours ago, daver328 said:

Waiting for E, F and J owners to call you a liar ... Err ... Accuse you of Exaggerating your airspeed. It happens every time a C owner claims anything faster than 135. You had to have had a tailwind in all three/four directions!

So why can't my C be as fast as an E, F or J ?

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19 hours ago, Sabremech said: It's been a long time coming for me to get some performance numbers for my cowling mod. Today I flew a performance flight in my modified C and took my numbers. Previous data had my airplane at 148 KTAS. Today's numbers put me at 154 KTAS. I'm pleased with the initial numbers and I plan to fly several more flights and take the data again to verify with more than one flight.

With this and the decrease of CHT's by an average of 25-30 degrees Fahrenheit, I think I have a pretty good mod. The STC package is going together and I'm hoping to submit it in a couple of months and get the certification process going.

David

Waiting for E, F and J owners to call you a liar ... Err ... Accuse you of Exaggerating your airspeed. It happens every time a C owner claims anything faster than 135. You had to have had a tailwind in all three/four directions!

Liar!!! Pants on fire!!! Feel better Dave?

065c9735c0436579469e5d244247dea8.jpg

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1 hour ago, Marauder said: Liar!!! Pants on fire!!! Feel better Dave?

065c9735c0436579469e5d244247dea8.jpg

What kind of ASI is in the top left photo?

It is the original Mooney ASI. I sent it out to have it refaced a few years ago. Since my POH is in knots and MPH, I was able to have it refaced with the knots placed on the outside ring.

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