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F model vs J for shorter runways


spokewrench

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I owned an F for 19 years and have a J now which I've had for 10 years. As far as short field performance is concerned, there is no difference. As far as cruse performance is concerned, contrary to popular belief, there is very little difference. My current J has a turbo, so it is not apples to apples, but at 6500 feet my F would do 152 at 75% and my J does 152 at 75%.

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I owned an F for 19 years and have a J now which I've had for 10 years. As far as short field performance is concerned, there is no difference. As far as cruse performance is concerned, contrary to popular belief, there is very little difference. My current J has a turbo, so it is not apples to apples, but at 6500 feet my F would do 152 at 75% and my J does 152 at 75%.

 

Huh ? I thought the "J" was supposed to be  about 10 knots faster than a "F" ?

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It is probably my plane.

 

It was wrecked three times before I bought it. Two gear up landings and hit a tree on an approach. The previous owner flew it home 300 miles with a one foot indentation in the right wing after hitting the tree.

 

When I bought the plane it would only do 142 at 75%. After tweaking and re-rigging I got it to the 152 it does now. If I level it off at takeoff power it will do about 170, but I don't want to burn 18 GPH!

 

I don't beleve what Sandman told me about the power settings of this engine. He said that at the same manifold and RPM it makes the same power as the stock engine. That is what the STC says also, but he never did a dyno run to confirm, so it is all a guess. Contrary to popular belief the turbo does take some power to operate and that power is not going to the propeller.

 

 

It would be interesting to see what everybody's planes would do at full power to get a comparison. We would need to know the temperature, altitude, manifold pressure and RPM.

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If short field take off performance is really a concern, Flap and Aileron gap seals will help. They are about $500 for both.

If gap seals make the difference in making it out of a field or not, you probably shouldn't be using that field.

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From a flying point of view there is not enough difference to matter. The J has a better panel. The F has the good mags! The F has more leg room for the pilot. The F with the Johnson Bar is a far superior gear system. The electric flaps on the J are better then the hydrolic on the F, but the F flaps are OK. The control systems are slightly different, I liked the feel of the F better. The J engine cowl is easier to get the whole thing off, The F cowl is easier to get normal access to the engine.

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In my F there was nothing on top of the wheel well and my knee would just go into that space. On the J, My 77 anyway there is a solid box that houses the throtle quadrant and it fills that space so there is nowhere for my knee to go so I have to keep my legs together. It just feels more cramped to me.

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A 76 F model is damn near 77 J model......the difference being about 10 knots and $20K. I have owned a stock 76 F and I now own an 81 J. The biggest speed advantages are in the climb and descent........the J model is cleaner with less drag. The cruise speed difference is about 10 knots.

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my J has the good mags,  Actually, Bendix 1200s kick the heck out of S20s,  and  it does 155 ROP,  150 LOP, 167 at sea level all out.

 

It also has the nicer panel, long windshield, inner gear doors, and flap seals.  You can put these on an F and have a J.

 

Downsides are more cost , as Greg said, around 20 grand, and electric gear only.  I really wanted a 1978 201, but the 1977 will do just fine.

I also have a 1977 sailboat and wife.  That was a heckuva year for toys, I tell ya!

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Thanks for all the help ! Hard to decide if the "J " is worth the extra cost over the " F" . I am sure a lot of you pondered this prior to your decisions -
My F has the 201 windshield, gaps seals and cowling enclosure. I routinely see 154 knots TAS at altitude. I think the biggest bang for the buck is the windshield. The rest is parasitic drag and can be cleaned up. Sent from my Nexus 7 using Tapatalk HD
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An F should have better take off performance, because most are generally a bit lighter than the J's. It would be marginal though. If you're looking at the 201 MSE models, they are very heavy and definitely need more room to get airborne - specially at higher density altitudes.

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Sounds to me like Turbo has a very fast F and a very slow J. My '89 J at 7,500 ft standard conditions, full throttle for about 65% power measures out on four-way GPS at 163 kts. I have done this test several times, always with about 3/4 fuel and alone. The slowest was 160 kts and twice at 163 kts. I don't have a turbo but I found careful attention to rigging added about 3 kts.

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Sounds to me like Turbo has a very fast F and a very slow J. My '89 J at 7,500 ft standard conditions, full throttle for about 65% power measures out on four-way GPS at 163 kts. I have done this test several times, always with about 3/4 fuel and alone. The slowest was 160 kts and twice at 163 kts. I don't have a turbo but I found careful attention to rigging added about 3 kts.

 

You are exactly right The F I used to own was the fastest F I ever saw. My J is a dog... but I still love it...

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This is Just my two cents and why I love this site so much The F was my first Mooney and I loved her for 5 years...what a great airplane, but over the years I found myself spending thousands of dollars trying to make her look like a J. So if you are comfortable with the vintage look either choice will get you into a Mooney which in my mind is all that really matters.

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Sounds to me like Turbo has a very fast F and a very slow J. My '89 J at 7,500 ft standard conditions, full throttle for about 65% power measures out on four-way GPS at 163 kts. I have done this test several times, always with about 3/4 fuel and alone. The slowest was 160 kts and twice at 163 kts. I don't have a turbo but I found careful attention to rigging added about 3 kts.

 

Those are my numbers also.....162 to 164 kts.

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