Jump to content

New Guy - Turbo vs. Non-Turbo


Recommended Posts

Agassi70,

Welcome to MooneySpace!

The turbo charged mid-body Mooney (231, 252 or Encore) will be about 10-15 knots faster than a 201, but only above 10K'.  The turbo charged version will cost you more to maintain and will burn more fuel.  They typically have lower useful loads and require more attention to engine management.

Whether it is worth it, depends on you particular mission and operating environment: How often do you operate from high density altitude airports?  How much useful load do you need to meet your mission? How many of your trips are longer than 300 nm?  Do you mind wearing oxygen cannulas or masks?

The mid-body turbo charged Mooney's improved over time.  The first 231's came with TCM TSIO360-GB engines, which suffered several problems.  The early 231's have been cited as being a very high pilot work load a/c.  Most of the -GB engines have been changed out to the -LB version and many of those have been equipped with after-market intercoolers and automatic wastegates, which many claim lower the pilot workload.  The 252's were equipped with the -MB engine which came with OEM intercooler and automatic wastegate.  The 252 is often cited as the "best" model Mooney ever made.  The last of the mid-body turbo Mooney's was the Encore with a 220hp TSIO360-SB engine and a gross weight increase.  Few were made and they are most sought after and are expensive and hard to find.

You may also find Lycoming powered F-models and 201's equipped with after market turbo chargers.  Ken Reed will probably be along an tell you about the simplicity of his turbo normalized F.  Two types of turbo charging  have been fitted to 201's. The first was the "Turbo Bullet" STC, where low compression pistons were installed into the Lycoming IO360, but they had to subquently limit the max operating MP due to a fatal crash and is probably a scheme I would stay away from.  A latter STC is the M20-Turbos turbo normalized scheme, which is operates at sea level pressures, but is costly to add to a J.

I leave it to others to speak of the virtues of the NA Mooney models.

Quote: agassi70

I am looking at buying a 201.  What is the speed difference between the turbo and non-turbo?  Is it worth it?  Looking at a 1977 or newer...  What mods should I look for?  What should I stay away from?

Thanks...

Link to comment
Share on other sites

Hi Ken, I think TN is a great option, but for us who have never used a turbo please share:


What kind of extra maintenance is involved? Dos this affect time/price for annual inspections?


Does the turbo have a TBO or useful life?


If I were to do a prebuy inspection on a TN equipped airplane, what am I looking for?


Thanks

Link to comment
Share on other sites

I have the 231.  The reason for a turbo for me, is long trips.  If your primary mission is trips of an hour or less, it is probably not worth it to buy the turbo because it does not pay to make the climb to higher altitudes where the turbo has an advantage in speed, and the maintenance costs are higher with the turbo.


The real advantage of the turbo, and the reason I got a turbo, is comfort.  The envelope in which a normally aspirated plane functions best is also where the most thermal turbulence exists most of the time.  When the summer "popcorn" cumulus builds up in the midwest where I live, flying under the bases is bumpy, getting over the bases requires flying in the high teens or low 20's.  It is way smoother up there, and much more comfortable for passengers who are not used to the bumpiness.  The aircraft also has a significant speed advantage over its normally aspirated cousins in that altitude range.  We did a round trip from MSP to MEM a couple of weeks ago, and it was the perfect plane for that.  Good fuel efficiency, good speed, and we were above the deck most of the time where the girlfriend liked the severe smooth.  Turn on the sat radio and cruise.


By comparison, I did a long flight in a rental Skyhawk a couple of months ago from Minneapolis to southern MO, could not get above the lower level turbulence, and it was really rough the entire way.  Uncomfortable even for me, and a very long trip.

Link to comment
Share on other sites

Quote: Bacachero

Hi Ken, I think TN is a great option, but for us who have never used a turbo please share: What kind of extra maintenance is involved? Dos this affect time/price for annual inspections? Does the turbo have a TBO or useful life? If I were to do a prebuy inspection on a TN equipped airplane, what am I looking for?

Link to comment
Share on other sites

i will have to agree with t he higher cost of a turbo but if that is not a problem they are really great. Even at lower altitudes they climb better, the engine is consistant through all altitudes and the airplane responds when you need it. Even on a 100 mile trip you will see the benefits. It will climb faster so you will go to 8-9 thousand feet when you would not even attempt to with a NA plane. Smoother air, cooler in summer, and safer. They do not fly around the field and make short 40-50 mile trips. If you live in hot parts of the country and fly cross country trips it works. But I flew a Turbo for 10+ years, I may not be a good source of info. Why do i fly a Ovation, I cannot afford an Acclaim.

Link to comment
Share on other sites

I can't understand the thing about the higher cost of a turbo. Everyone seems to repeat that like a mantra. With an 1800 TBO, you may have to rebuild the turbo once, and maybe a section or two of exhaust. Perhaps $3000 to $4000, less if you're partaking in the maintenance. But if you're flying even 100hrs/year, which for most GA pilots is a lot now, that expense is spread out over 18 years! Your fuel burn alone would cost you over $5K annually (12 gph @$4.50/gal, less if LOP at 9 gph)  -  this is what we should focus on. If so, then you'll realize the M20K is probably the most efficient 4-seat piston aircraft in the GA fleet. With the added utilities of cruising high altitude operatins, speed, and the best MPG on the market, why would anyone not want a turbo'd Mooney?

Link to comment
Share on other sites

It not just the cost of the turbo.  It is the effect of the higher temperatures on cylinder life and other components and of course maintaining 6 cyl on the TCM TSIO360 vs 4 cyl on the Lyc IO360.  Pretty routnine that many TSIO360 need a top overhaul around 1,000 hrs whereas IO360 usually make TBO.  Also some TSIO360 don't operate well LOP, however mine does.  YMMV.

It all depends on the specifics of your mission, operating environment and the depths of your pockets.

Alan

Quote: 231BB

I can't understand the thing about the higher cost of a turbo. Everyone seems to repeat that like a mantra. With an 1800 TBO, you may have to rebuild the turbo once, and maybe a section or two of exhaust. Perhaps $3000 to $4000, less if you're partaking in the maintenance. But if you're flying even 100hrs/year, which for most GA pilots is a lot now, that expense is spread out over 18 years! Your fuel burn alone would cost you over $5K annually (12 gph @$4.50/gal, less if LOP at 9 gph)  -  this is what we should focus on. If so, then you'll realize the M20K is probably the most efficient 4-seat piston aircraft in the GA fleet. With the added utilities of cruising high altitude operatins, speed, and the best MPG on the market, why would anyone not want a turbo'd Mooney?

Link to comment
Share on other sites

There in lies the rub. How one flies (fries?) the engine has much to do with its longevity. How often, how hard, how the throttle is handled, and how meticulously the baffling is maintained. Although some lore seems to point to early top overhauls on some TSIO360's, I've always wondered how people are treating these engines. Do these engines all have multi-probe temp monitoring, are they regularly run, and is the pilot pushing 39" MP on a 90 kt climb all the way to 15,000ft? If the MTBF for a TSIO360 is indeed 1000 hrs, why would TCM certify them for an 1800 TBO? I have seen other Lyc & TCM turbo'd engines fried more by pilot mismanagement and poor maintenance/temp monitoring. Because the boost is there doesn't mean you have to use it all the time - I agree this will shorten any engine's lifespan.


So short of buying 4 extra plugs for cylinders 5&6, I haven't seen the added expense everyone talks about. And yes, I have a TSIO360LB with over 1000hrs, still with uniform compressions in the 70's and minimal oil burn. CHT's run 300ºF or less in cruise (65% power) and low 300's at cruise climb. I do not run LOP on WOT. Another pilot on the field with an M20K, also a believer in smooth engine management, saw 1800hrs+ on his first engine, and is well past 1000 hrs on his second with no sign of cylinder wear. Sure, this may be my OWT, but one OWT deserves another.

Link to comment
Share on other sites

Why I went turbo...


Took N262MB over the "big rocks" west of Denver for the first time to attend the 3rd Annual Never Summer Fly-In at Walden-Jackson County Airport (33V) where Traffic Pattern Altitude is 9,200' msl and the surface temperature 22 degC above standard temperature on Sunday.   I was about 100 lbs below gross weight.   See the pictures from the Walden fly-in in my Gallery.


However in the interest of full disclosure:  there was a NA Mooney (N202PC) in attendance too!

post-18-13468138469579_thumb.jpg

Link to comment
Share on other sites

  • 2 months later...

This thread compelled me to join MooneySpace and share my thoughts.  Not to mention, since Allen called out my N# (N202PC), it seemed appropriate to jump into the fray and share my opinion.  For me, I went Normally Aspirated purely for economics.  My research confirmed a general truism of turbos: you’ll need a top end rebuild at about 1000 hours and it will typically cost more.  Beyond burning more fuel, you’ll likely have to lug Oxygen along on your trip to really enjoy all the high flying turbo benefits, lowering your useful load and cabin space. And refilling the bottle costs money too.  I went NA Mooney to get what I think is the best balance of speed and economy – 155 Knots true on 9.5 GPH at FL-120 for nearly 6 hours endurance – that’s pretty tough to beat. 


Enough stats, let’s talk about the NA version of the “never summer” fly in so you can compare my experience with Allen’s.  Normally, I fly a few hundred pounds under gross and have fair performance over the big rocks. But for this trip, I was at gross – the whole family of 3 plus mother-in-law in tow along with all our camping gear and fuel to tabs.  I left home base of APA (5800 feet MSL) around 10:30 local and it was already hot – at least 85 degrees.  The ground roll was much longer than normal and the climb rate was barely 500 FPM that day.  To clear Rollins Pass (the locals call it Corona Pass) you need to be at least FL-125 to clear the rocks.  On top of that, the wind coming over the ridge that day was creating a pretty fair downdraft.  It was clear that we weren’t going to clear the pass on the merits of the Normally Aspirated engine alone.  I turned back from the pass, found a ridge making a nice updraft from the wind, banked to 45 degrees and rode it up like an elevator.  We stepped off the updraft at FL-140 and cleared the pass with plenty of air to spare.  I explained the procedure to the mother-in-law before the updraft and bank; she thought the ride up was a hoot.  Of course, she was also on board with camping out of an airplane ;)  


At any rate, I love my Mooney and the only time I wished for a turbo was the 1 or 2 times I wanted to file Instrument over the big rocks and the MEA was FL-160.  But, I was able to find a lower altitude route further around the hill.  It took longer, but we didn’t have to lug any O2 around and were less likely to pick up ice.  So, there you have it – happy shopping!


Bret Lowell

Link to comment
Share on other sites

Bret, very interesting reading. I'm trying to visualize the ridge where you caught the updraft. I supposed it was a ridge that was downwind of the pass enough that you could get on the windward side and climb up the air current to get the altitude you needed? That's some fancy airmanship...glider training perhaps?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.