POWER FLOW EXHAUST

[Lonesomeness Dove]

HAS ANY ONE HAD THE PF UPGRADE?

[aerobat95]

I havent really heard much on this either and am interested as well.

[PTK]

I'm looking into the PF as well. Any pros and/or cons. Is it worth it?

[N33GG]

I have been wondering the same thing... glad to see the post.  Should be interesting.  My C-Model could use a little extra ooompf.

[John Pleisse]

I was told by my MSC IA, if you end up needing costly exhausy work, it worth it to take the plunge and their performance claims are accurate. I also heard early production had problems with fit and finish, but those issues are addressed. Again, word of mouth.

[John Pleisse]

How about this....Powerflow and a top prop........ $15k would buy you a lot of performace....and reliability. I am due for both. No major exhaust work in 13 years.......600 SPOH (6 yrs), 3rd run on blades. It migh be time....

[aerobat95]

That would be a pretty sweet combo....I wonder what sort of performance gains you would see???

[stevesm20b]

I have heard a number of reviews and claims of 5 to 10 mph increase is speed along with better clime performance. That would make a B or C model perform better than an E model. I also understand the it may not fit the early models with generators. I would also be very interested in hearing from anyone that tried it. 

[AlexR]

I got one in 2008.  I noticed about 4 knots up high and a little less down low.  The exhaust is tuned for wide open throttle and 10,000ft.  I also got 150fpm more climb and fuel consumption went down about .4 gph.  I was just at Oshkosh and Powerflow was offering a group buy discount....out the door between 3,500-3,100 for the stainless system.   Annoying because I paid about 4k.  Highly recommend.

 

[N33GG]

Quote: AlexR

I got one in 2008.  I noticed about 4 knots up high and a little less down low.  The exhaust is tuned for wide open throttle and 10,000ft.  I also got 150fpm more climb and fuel consumption went down about .4 gph.  I was just at Oshkosh and Powerflow was offering a group buy discount....out the door between 3,500-3,100 for the stainless system.   Annoying because I paid about 4k.  Highly recommend.

 

[John Pleisse]

Quote: aerobat95

That would be a pretty sweet combo....I wonder what sort of performance gains you would see???

[aerobat95]

Thanks...so far the 201 windshield is going pretty good.  Not to much more in the lines of Mods...maybe some flap gap seals, and oil cooler relocation, and a wing root leading edge fairing (for looks).  I am thinking I am going to stick with the cowl I currently have...I really do like the looks of the Top Prop....who knows that may be a future add as well.  Its too bad a IO390 is so expensive.  The perfect combo for me would be a IO390, Top Prop, and Powerflow Exhaust....that would be a pretty sweet set up.  Maybe like one of the guys said...the top prop and a powerflow exhaust....

[M016576]

Quote: AlexR

I got one in 2008.  I noticed about 4 knots up high and a little less down low.  The exhaust is tuned for wide open throttle and 10,000ft.  I also got 150fpm more climb and fuel consumption went down about .4 gph.  I was just at Oshkosh and Powerflow was offering a group buy discount....out the door between 3,500-3,100 for the stainless system.   Annoying because I paid about 4k.  Highly recommend.

 

[AlexR]

Quote: N6719N

 Which model of Mooney do you have?

[John Pleisse]

Quote: aerobat95

The perfect combo for me would be a IO390, Top Prop, and Powerflow Exhaust....that would be a pretty sweet set up.  Maybe like one of the guys said...the top prop and a powerflow exhaust....

[fantom]

Quote: M016576

[M016576]

Thanks for the info, guys.  I'm still looking into this.  Anyone have any links or articles detailing E/F/J Performance gains (or lack thereof?) or is it all word or mouth...  Thanks!

[fantom]

No.....and no ;-)

[M016576]

Fantom-  I've found a couple articles referencing 4-5kt gains on the NA O-360 Mooneys, are you saying that the stock exhaust system is well tuned enough to not make a difference if it's replaced?  (begging for more than a one word response... ;-))!

[M016576]

I just read this plane & pilot article detailing the installation and test ona M20F with the IO-360... in cruise the author reported a 5kt gain in speed, plus lower CHT's, .5gph fuel burn and higher climb rates.  Looks like his 20F has a LoPresti cowl and 201 speed mods... so I'd be willing to be that the gains would be similar on a 201. 

Does anyone have anything other than hearsay that counters this report?

link:  http://www.planeandpilotmag.com/aircraft/modifications/accelerating-a-mooney.html

[fantom]

I to have been in too many sessions on the PF muffs, read stories on many forums, and spoken to more than a handful of people who both installed and sometimes took them off and returned them. I've also talked to the PF people directly. Like all performance increase claims, I followed it closely PF when it came out, and like most, the promise exceeded real performance. Try to get a guarantee on those performance claims. It won't happen, and I don't know if they still have a return policy, after install, unintall, shipping and restocking costs.

I think you may get a couple of knots on an NA O-360, and a bit better climb, at the expense of a slightly increased fuel flow, and some added ongoing maintenance needs. If you are already in need of rebuilding your exhaust system on an older Mooney, I guess you could justify one.

On an IO engine, especially a J, all you'll get is a fuggly exhaust. Other makes may have a different story. Good luck in any event.

 

 

[M016576]

Quote: fantom

I to have been in too many sessions on the PF muffs, read stories on many forums, and spoken to more than a handful of people who both installed and sometimes took them off and returned them. I've also talked to the PF people directly. Like all performance increase claims, I followed it closely PF when it came out, and like most, the promise exceeded real performance. Try to get a guarantee on those performance claims. It won't happen, and I don't know if they still have a return policy, after install, unintall, shipping and restocking costs.

I think you may get a couple of knots on an NA O-360, and a bit better climb, at the expense of a slightly increased fuel flow, and some added ongoing maintenance needs. If you are already in need of rebuilding your exhaust system on an older Mooney, I guess you could justify one.

On an IO engine, especially a J, all you'll get is a fuggly exhaust. Other makes may have a different story. Good luck in any event.

 

 

[PTK]

According to Bill Cox's article, if I'm reading it correctly, the most advantageous gains are 2 or 3 knots and happen at 11500 at 2500 rpm and peak. Seems to me these are small gains in a very restricted regime and when the stars are aligned a certain way.  I don't think it's worth it imho. I'm speaking about the J.  If it was down at "normal" prices maybe. It's like most other mods. Their cost /benefit or cost/gains ratio is exhorbitant. When I bought my plane I had a discussion with a mechanic at Dugosh who had maintained it and annualled it since it was born practically.  He made me think. We were talking about mods and the Loprest cowl. I think at that time it was around 14K or somewhere near there if I remember. He said to me, would you pay 14 grand plus installation for a questionable 2 or 3 knots?  The answer is no! His opinion was don't buy it for promised gains because you'll be disappointed.

[AlexR]

Quote: JimR

I know of a C model owner who really did get a 4 knot speed increase from a PowerFlow installation at altitude.  Fuel flows went up noticeably, too, at WOT power settings.  More air flow requires more fuel flow, so unlike the aerodynamic mods the only way that you can have an efficiency increase as a result of a PowerFlow installation is to pull the power back to your previous WOT cruise speed.  Not many pilots are willing to do that, so you'll be climbing and cruising a little faster and burning more fuel.

What Gary is referring to is that many people claim less success with the PowerFlow in fuel injected Mooneys like the E,F, & J.  I have no idea why but I've heard it enough to believe there must be some truth to it.   

To obtain maximum service life from a PowerFlow exhaust the company recommends that the slip joints in the exhaust be lubricated periodically.  If you're not doing this already it would add a bit to your maintenance bills, but it's probably a good practice to do anyway.

Personally I decided that the juice probably isn't worth the squeeze to me for my J model, but I feel that way about most modifications and "upgrades" when the OEM equipment has a long and well-established service history.  

Jim 

 

I actually got a slight (.4gph on average) fuel flow reduction at cruise.  I think the reason why is the new exhaust helped to balance my EGTs (all over the place on carburated engines) which allowed me to lean a bit further (LOP in summer, and just one jug barely in the rich side in winter) than before.   You are correct that fuel flow in the climb is higher.  I agree that owners that seem to benefit the most are carburated.

-Alex  

 

[M016576]

Seems like the IO-360 has either a better stock exhaust system than the O-360 on the mooney just from what I'm reading here on this board and through the word of mouth reviews.

As for the decision to buy a PF: Some of the folks on the board have been upgrading their aircraft lately, trading in their C/E/F/J's for K's, Ovations, Rockets, etc. For those of us that aren't interested in getting rid of their aircraft, but are still seeking a bit of an upgrade in speed/performance, the PF seems like a pretty decent answer. Maybe the fuel fuels do increase, but if you get an extra 2-5 knots, that's a pretty significant upgrade. The extra fuel burn may be worth it if it's a justifiable performance upgrade. The upgrade to a K burns more fuel, and the performance is maximized above 8-10K (where the Turbo really starts to give you the extra performance vs a NA engine). How much extra speed do you get... 10kts? 15kts? really the measurable upgrade is in the ability to get into the teens and take advantage of the winds. For those of us that target 8 to 10k as their mission altitude, perhaps the PF exhausts maybe a way to both enjoy an upgrade in speed (2-5kts.. so anywhere from 10%-50% of the speed gain of a K) without a significantly higher fuel burn (2-3gph).

From a cost perspective, here's what I'm thinking: $3500 bucks for the exhaust, plus a little for the yearly lubing vs the cost of selling in a depressed aircraft market and purchasing a K or better, which could be as much as 10-15k for a like model, although perhaps more depending on how the K is configured and maintained...

I guess what I'm looking at is that the PF, even for a J, *SEEMS* like a great way to squeeze more performance out of an aircraft that is perfect for my mission already, without having to incur the cost penalties of upgrading to a whole new airplane.

As far as other speed mods are concerned, like moving antennas around, flap/gap seals, rotating brakes, new cowlings and smooth belly pans all seem like they will get you a little more performance as well, but cost as much as the PF. So it seems to me like the PF exhaust is one of the more effective "speed mods" for cost per performance gain that you can purchase, assuming your mission drives you into the 8-11k altitude region.

With all that in mind, I'm actually going to pass on this mod (more because I'm just not in a place to spend the 3500 bucks right now on a mod, as I don't want to drain my maintenance slush fund right now with my annual coming up at the end of the year).

My question to the critics is this: where am I going wrong in the above statements? Is it mearly a factor of the potential for unsubstantiated gains? or is it something else? Either way, I appriciate all the opinions in the forum and am curious to see what everyone things about my point of view described above....