Mooney Acclaim STC

[daveydog]

I had a question for anyone who drives an Acclaim and has upgraded to the Midwest Mooney STC for 310 hp.  Im interested in knowing if the increase from 280 to 310 was as dramatic as claimed and how the G1000 was upgraded to accolade the 2700-rpm. Any performance comparisons would be great to those who have this STC.  Thanks!   

[Piloto]

Doing the math the most you will get of this mod is an extra 7kts and 200 fpm.

 

José

[carusoam]

Davey, you may want to open your question to up to people with ovations and eagles.

Unless you are asking questions really specific to turbo ops.

Best regards,

-a-

[xftrplt]

Quote: Piloto

Doing the math the most you will get of this mod is an extra 7kts and 200 fpm.

 

José

[Piloto]

Quote: xftrplt

[Piloto]

Quote: xftrplt

I may be wrong, but I believe 7kts is optimistic. Power required goes up with the cube of velocity; therefore, an extra 30hp is an 11% increase. The cube root of 11 is about 2%. And .02 x 180kts = ~4kts.

[xftrplt]

José is certainly correct.  FWIW, FF increases 11% for a 2.2% increase in speed.  You pays your money and takes your choice. 

[daveydog]

Thanks everyone, and I certainly appreciate feedback from Ovation 2/3 drivers as well.  I was interested in acclaim drivers specifically because turbo operation is impacted very differently.  For instance, the MP requirement for the acclaim is 34" at 2700RPM.  Non-turbos will never reach this MP, therefore, fuel flows are also impacted.  The STC states that fuelflow must matched to increased RPM and also should be redline fuelflow at takeoff to establish a benchmark for leaning at altitude.  This has particular interest to me.  

 

Also, I was very interested from hearing from Acclaim drivers who already have it.  Theory or marketing claims versus actual results.  Anyone flying the 310 STC on the acclaim would be very helpful to hear what performance actually is. Thanks again.  A lot of smart guys out there.  Jose, I need to trust you on the math... LOL... my math SAT's will prove that I am not suited to be an engineer!  )

[Cris]

I might suggest a call/e-mail to Mat at Midwest Mooney matt@midwestmooney.com (618) 662-3377 who performed the upgrade on my Eagle from the early 280 HP STC to the 310 HP last Jan. Simply ask Mat for references of Acclaim owners that you might speak to about their real world experiences. They would have the info that you are looking for but may not be part of this board.

[daveydog]

great idea!  Thanks. 

[Piloto]

Quote: daveydog

Thanks everyone, and I certainly appreciate feedback from Ovation 2/3 drivers as well.

[Piloto]

Quote: daveydog

Also, I was very interested from hearing from Acclaim drivers who already have it. Theory or marketing claims versus actual results. Anyone flying the 310 STC on the acclaim would be very helpful to hear what performance actually is. Thanks again. A lot of smart guys out there. Jose, I need to trust you on the math... LOL... my math SAT's will prove that I am not suited to be an engineer! )

[orangemtl]

I'll be interested as well to hear from pilots who have installed the upgrade. Does it alter the TBO? I know the engine is already rated to 310 in other applications.

As in all things, it comes down to $: if it was free, we'd all do it; if it's $20,000, then: that would buy quite a bit of fuel, and I can't really see the difference between 200kts and 204 kts looking out the window.

I recall speaking to an instructor/operator in Texas about this a few years ago, and his opinion was "meh". Not, however exactly a thorough, articulate analysis!

[RobertoTohme]

For those interested, here are tables I gathered from flights with my 310hp Acclaim, both before and after the type S conversion.   Compare your actual times w/ 280 HP to the tables below.  Back in the day, I reported this figures to Midwest for analysis.  Of course, the notorious improvement was the climb time, as the speed gain was, in my case, 3 kts at best.

Cheers.

 

Climb Data for Acclaim N118RT with 310 hp STC.

Flight date: 12/30/2008

Before Type S Conversion

Departure airport :  KELP

Elevation: 3,920 ft.

Ft.

IAS (kts)

Time

OAT C°

RPM

MP (in.)

        6,000

115

2:20

9

       2,700

33.2

        8,000

115

4:00

10

       2,700

33.5

      10,000

115

5:45

8

       2,600

33.2

      12,000

115

7:35

4

       2,600

33.1

      14,000

115

9:29

0

       2,600

33.0

      16,000

115

11:28

-3

       2,600

33.1

      18,000

115

13:30

-9

       2,600

33.0

      20,000

115

15:54

-15

       2,600

32.9

      22,000

115

18:06

-20

       2,600

32.8

      24,000

115

20:36

-25

       2,600

32.6

      25,000

115

21:51

-27

       2,600

32.4

Flight date: 12/30/2008

2/4/2009

After Type S Conversion

Departure airport :  KELP

Elevation: 3,920 ft.

Ft.

IAS (kts)

Time

OAT C°

RPM

MP (in.)

        6,000

115

2:10

 

       2,700

32.8

        8,000

115

3:42

 

       2,700

33.5

      10,000

115

5:20

 

       2,690

33.5

      12,000

115

7:00

 

       2,690

33.4

      14,000

115

8:44

 

       2,690

33.5

      16,000

115

10:28

 

       2,690

33.5

** at 16000 reduced RPM to 2600

      18,000

115

12:24

 

       2,600

33.1

**altimeter change from 30.42 to 29.92

      20,000

115

14:50

-20

       2,600

33.0

      22,000

115

16:59

-24

       2,600

32.7

      24,000

115

19:25

-27

       2,600

32.4

      25,000

115

20:45

-28

       2,600

32.3

 

 

 

 

[RobertoTohme]

Whatever happened, seems like the second table is missing on the previous posting...  If interested, let me know and I'll email the excel file....

[daveydog]

First off ... thanks again to all for the great insight.  That said, my wife feels less satisfied because I dropped the dough I was going to use for an extented vacation and I did the STC on the Acclaim instead.  I gave her all your contact information!  LOL.

Seriously, It's not perfect yet, but its an impressive climb.

Performance on three flights:

Elevation in Boulder is 5050 (KLMO).  34"/2700 full rich climb was a steady 1700-fpm climb at 120 knots.  Baro was on average 30.25" (great weather lately) and 80 gal. of gas and me (220 lbs). Other two flight very similar.  So the consensus at this point is the upgrade was well worth it to me.  

I won't use the 2700 rpm on every takeoff, but if I'm at gross, high density altitude, I like the extra 30 hp (and yes, it makes a huge difference).  I also like it for breaking through an icing layer, or just getting on top faster.  

In terms of programming, there are some issues that remain.  

The STC does not yet address the G1000 for programming, but Matt at MidWest Mooney assures me he will resolve this ASAP. (Matt seems to be a great guy to work with as well).

The Manifold pressure on the G1000 does not red line (as it should) at 34" since the G1000 must be programmed as an Ovation (need to trick the G1000) so it believes the engine is 310 hp, which it now is, but this leaves a manifold pressure issue in terms of programming since the TSIO 550G must not exceed 34" manifold.   The non-turbo Ovation will never see 34", therefore, its mute, but very relevant for the turbo Acclaim or other turbo's if they are behind a TSIO-550G engine.  

This meant that the manifold pressure needed placarded until the programing correction takes place.  This is a little troubling if you want to see a red-line indication.  For me, I don't care that much, but for re-sale it definitely matters.  I will have the controller dialed back to 34" so if fire-walled, the manifold will max out there, but this has yet to be done.  The reason I want this is because N343BK jumps pretty fast and I don't want to play with dialing in the Vernier to peak at 34" (or dialing in 2700 on the blue knob).  I want these both to be at 34"/2700 at firewall.  Right now, that is not the case and its just one more thing to manipulate during takeoff.  While not a big deal to handle, why not perfect the procedure without needing to monitor the throddle/RPM too closely.  Id rather slowly dial in the power to firewall and look down the runway than scan for over powering the manifold/RPM.  

As far a unleashing the engine to do what it was built to do (310 hp), I still can't understand why Mooney de-rated the engine at the factory for 280-hp.  I spoke to TCM before I did the STC and they said to go for it.  Its what it was built to do.  So the only thing I can imagine is trying to help ensure the engine goes to the stated 2000-hr. TBO.  

Anyway, its a marked improvement to an already amazing take-off.  By the time I'm out of ground effect and wheels up, it's time to bring the flaps up because I'm at the end of the white arc, and at Longmont (KLMO) where have 4950 ft. of runway, that all happens before the departure end of the runway.  

This leads to my next quest which is to consider the Monroe Upgrade and wet out the wing.  I often will fly from CO to PA (1375 nautical) and with a "little johnny" and a LOP setting, I could easily make it with this STC, so any thoughts from those that have it would be, once again, GREATLY APPRECAITED!

I will keep the updates coming on the 310 upgrade and thanks to all who weighed in on this discussion!  

 

[daveydog]

I did the STC on the Acclaim.  It's not perfect yet, but its an impressive climb.

Performance on three flights:

Elevation in Boulder is 5050 (KLMO).  34"/2700 full rich climb was a steady 1700-fpm climb at 120 knots.  Baro was on average 30.25" (great weather lately) and 80 gal. of gas and me (220 lbs). Other two flight very similar.  So the consensus at this point is the upgrade was well worth it to me.  

I won't use the 2700 rpm on every takeoff, but if I'm at gross, high density altitude, I like the extra 30 hp (and yes, it makes a huge difference).  I also like it for breaking through an icing layer, or just getting on top faster.  

In terms of programming, there are some issues that remain.  

The STC does not yet address the G1000 for programming, but Matt at MidWest Mooney assures me he will resolve this ASAP. (Matt seems to be a great guy to work with as well).

The Manifold pressure on the G1000 does not red line (as it should) at 34" since the G1000 must be programmed as an Ovation (need to trick the G1000) so it believes the engine is 310 hp, which it now is, but this leaves a manifold pressure issue in terms of programming since the TSIO 550G must not exceed 34" manifold.   The non-turbo Ovation will never see 34", therefore, its mute, but very relevant for the turbo Acclaim or other turbo's if they are behind a TSIO-550G engine.  

This meant that the manifold pressure needed placarded until the programing correction takes place.  This is a little troubling if you want to see a red-line indication.  For me, I don't care that much, but for re-sale it definitely matters.  I will have the controller dialed back to 34" so if fire-walled, the manifold will max out there, but this has yet to be done.  The reason I want this is because N343BK jumps pretty fast and I don't want to play with dialing in the Vernier to peak at 34" (or dialing in 2700 on the blue knob).  I want these both to be at 34"/2700 at firewall.  Right now, that is not the case and its just one more thing to manipulate during takeoff.  While not a big deal to handle, why not perfect the procedure without needing to monitor the throddle/RPM too closely.  Id rather slowly dial in the power to firewall and look down the runway than scan for over powering the manifold/RPM.  

As far a unleashing the engine to do what it was built to do (310 hp), I still can't understand why Mooney de-rated the engine at the factory for 280-hp.  I spoke to TCM before I did the STC and they said to go for it.  Its what it was built to do.  So the only thing I can imagine is trying to help ensure the engine goes to the stated 2000-hr. TBO.  

Anyway, its a marked improvement to an already amazing take-off.  By the time I'm out of ground effect and wheels up, it's time to bring the flaps up because I'm at the end of the white arc, and at Longmont (KLMO) where have 4950 ft. of runway, that all happens before the departure end of the runway.  

This leads to my next quest which is to consider the Monroe Upgrade and wet out the wing.  I often will fly from CO to PA (1375 nautical) and with a "little johnny" and a LOP setting, I could easily make it with this STC, so any thoughts from those that have it would be, once again, GREATLY APPRECAITED!

I will keep the updates coming on the 310 upgrade and thanks to all who weighed in on this discussion!  

[daveydog]

is it my computer or is the forum posting incorrectly?  

[KSMooniac]

I see your post as a long, skinny newspaper-style column.... very hard to read and I'm wondering why the forum did that...doubt you had anything to do with it!

In any case, congrats on the upgrade!

[daveydog]

no, I didn't write it that way.  Can figure it out.  Must be a bust with the site.  Thanks 

[Chessieretriever]

I recomend the Monroe STC. We fly a Bravo with the Rocket 351 conversion (TCM TSIOL550) which is similar to your engine (low compression, water cooled and higher output on T/O but essentially the same everywhere else). We have flown Denver CO to our home base in PA 1400 miles non stop LOP using 104 Gallons in less than 6 hours with an hour+ of fuel left. So if we can do it you certainly can do that and then some with 130 Gallon on board. The problem becomes physiological rather than fuel at that point. The weight penalty of the Monroe is negligible; just need to keep an eye on W&B and fly high and LOP.

[ndesai]

I have recently acquired N118RZ (Acclaim) with the 310 HP Midwest upgrade. Looking for some recommendations on cruise settings LOP.

[Mcstealth]

"I have recently acquired N118RZ (Acclaim) with the 310 HP Midwest upgrade. Looking for some recommendations on cruise settings LOP."

We non turbo drivers prefer you use the Fire Breathing Dragon settings, and get back to us with Pireps and adventures.   Congratulations on your purchase. Welcom to the Forum. Recommend you Search this board for Acclaim related issues like the breather problem.

 

[RobertoTohme]

Congrats on your airplane!  I can tell you first hand it's a very solid performer, as I was the original owner...  Let me look at my notes and I'll post what it used to do for me in it's first 200 hrs back when I had it.  And again, enjoy it as much as I did!!  N118RT was a regular visitor to FL250 back then (I got my registration back and hence the change to Z).

Quote: ndesai

I have recently acquired N118RZ (Acclaim) with the 310 HP Midwest upgrade. Looking for some recommendations on cruise settings LOP.

[daveydog]

Congratulations on the new Acclaim.  It's an amazing bird.  I love mine.

Here is how I fly LOP and this is based on speaking with TCM and some pretty smart guys who seem to know the TSIOIO550G well.

1.  Full rich climb.  Full power is 34"/2700RPM, but thats not always necessary always.  If you want go hard, then thats max climb and good if breaking a layer, ice and snow layers, etc, but if your not in a hurry I will pull it back a bit.  Be ready to raise flaps as soon as wheels suck up because your out of flap speed at 100 IAS and that comes quickly.  If I don't want full power climb, At 500 agl, I pull RPMs back to 2600 and manifold to 33".  They suggest forgetting the LOP climb and I agree.  I have done it, but the efficiency improvement  is negligible in terms of fuel flow and time to climb.

2.  At Cruise, slowly bring manifold back to 30.5"/2500RPM.  TCM says don't be in a hurry.  Let it settle in and slowly dial it back.  Once trimmed and level 

3.  Press lean assist button on G1000 and somewhat aggressively lien until you hone in on 1600 TIT (big pull), then slow down and seek peak EGT/TIT indication on lean assist temp indication (it will show 0  and illustrate).  You many be around 1675 TIT or so...

4.  Continue to lean and monitor lean assist temp indication and slow the leaning down (turn knob slow) until -50 LOP.  Continue to monitor EGT as well and make sure coolest EGT is also at minimum -25 LOP.  It is possible to be -50 LOP on the hottest cylinder and also be at near peak on a cooler cylinder.  This is a problem.  Continue to lean so coolest cylinder also get to at least -25 LOP.  This will ensure all cylinders are truly LOP.  Very important.  As long as injectors are performing as they should (and NO, you don't need or want GAMI's... the TCM tuned port injectors that come with the TSIO550G is what you want)

5.  Depending on atmosphere, you should end up with about 29.5"/2500RPM and 17.5 GPH.  The engine will be smooth but perhaps a shade more harmonic, but still very smooth.  

6.  CHT's will be all at or below 380 and usually cooler... like 350's

7.  Dial up your aux screen on the G1000 and marvel at the efficiency and MPG.  Its like 12 MPG on many days.  Pretty darn good.  Thats Chevy Suburban fuel flow at 220-230 TAS.  With TKS you also get the 4X4 features!  Pretty Cool!

 

Other Acclaim Drivers, please share your approach.  We all learn from each other!