Power Flow Systems, Inc.
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Maule exhaust Pre-STC offer extended, 8 order commitments.

Revised 09.25.14 1300

Power Flow Systems is pleased to announce that initial research and development work has begun on a Tuned Exhaust System for the Maule MX7 series of aircraft, powered by four cylinder Lycoming engines, and that we have extended the deadline to December 31, 2014.

Number of confirmed Maule Pre-STC Deposits ordered as of 09.25.14: 8 (eight)

Current Deposit holder discount amount: $500.00.

Number of deposits required before STC program launches: 27.  Deadline for sign-up: Now December 31, 2014.

Additional number of deposits need for all depositers to get to higher discount of $600.00: 32

If you have been following the scoreboard on Power Flow’s web-site, you may know that there are currently eight confirmed depositors for our proposed new Tuned Exhaust System for the O-320 and O-360 powered Maule’s. 

We are still seeking an additional twenty-seven depositors to help Power Flow, Maule Inc., and their fellow Maule pilots get the STC development program off the ground.

The performance numbers we have published for the system were taken from actual before and after flight tests with the new Power Flow design.  The results were witnessed by Brett and Ray Maule and are documented in the video we have posted on the Maule portion of our web-site.  Those numbers provide real and compelling evidence of Power Flow’s value proposition for the worldwide community of Maule pilots.

Just as real and compelling, however, are the substantial investments in time, technical expertise and FAA mandated expenses that Power Flow will bear in order to bring this new system to market as a fully STC’d and properly supported upgrade.  To assume those liabilities without any assurance of a potential base of Customers for the finished product would be doing a grave dis-service to our existing base of more than 4,350 satisfied Customers as well as to Power Flow’s employees, owners and investors.

That said, we ARE in the business of developing and producing reliable, high performance Tuned Exhaust Systems for General Aviation aircraft.  Based on feedback from Maule, Inc. and its community of Customers, we KNOW that this otherwise fine aircraft sorely needs a more reliable and better performing exhaust system.  The flight testing referred to above conclusively demonstrates that our system WILL provide these benefits.

In light of these circumstances and in a good faith effort to move this project forward, Power Flow is extending the deadline for obtaining the additional 27 depositors to the final day of EAA’s AirVenture in Oshkosh which falls on Sunday, August 3 this year.

Prospects who have discussed the system with us to date have raised three main reasons for not placing an order:  #1.) Un-attributed reports that the Power Flow System is prone to cracking and is no more reliable than the stock Maule system we are proposing to replace.

As most rational people will understand, it is very difficult to discuss or refute vague remarks for which no specifics or verifiable details are given. 
We do admit, however, that there is actually a small grain of truth to this rumor:  Power Flow began shipping our Tuned Exhausts in 1999.  Between then and 2004 we did see an unacceptably high rate of cracking around the welded areas of the system.  To quantify: the failure rate was less than 3% of the systems we shipped, but both Power Flow and our Customers considered this to be unacceptable.  We studied the problem at length and implemented three fixes:

a.)    We slightly modified the geometry of our basic system to reduce the stress on the welded portions,

b.)    After finding that most of the systems that had cracked were installed on aircraft where the propellers were producing up to 10 X the levels of vibration considered acceptable by the FAA, we instituted a policy of doubling the warranty period on our systems from 12 months / 500 flight hours (whichever occurs first) to 24 months / 500 flight hours AS LONG AS: a dynamic propeller balance is performed on the aircraft within 25 flight hours of the Power Flow installation.  As noted in our PRE-STC sales agreement, this policy is now standard with our newer systems, including our new design for the Maule.

c.)    We made the recommended periodic cleaning and lubrication of our system’s four slip joints mandatory and part of the Instructions for Continued Airworthiness for our systems.

It is worth noting that the Power Flow System has no service life limit.  It is designed and built to last several thousand flight hours and will quite likely be the last exhaust system you need to buy for your Maule.  As with any high performance system however, it must be maintained properly.  Every 500 flight hours or annually (whichever comes first) the four slip joints on the system must be cleaned and lubricated with high temperature anti-seize compound. 

Most Customers have this maintenance performed during the aircraft’s annual inspection which adds about 2 hours of labor to the inspection.  We have had several of our Tuned Exhaust Systems rack up over 4,000 flight hours of trouble free performance (7,000+ flight hours is the record in a commercial operation) as long as this maintenance is performed as required. 

#2.  Uncertainty that the performance improvements, despite being documented and witnessed as described above, will actually materialize on their own airplanes;

#3.) Concerns about the final cost of the system which is admittedly significantly higher than the price for a simple replacement of the original design.

We could recite all kinds of sales jargon as a response to these last two legitimate concerns.  To give our current and future Maule flying Customers a better sense of what they have to look forward to, though, we think it would be more helpful to share some comments from some current Customers who made the tough decision to part with their own hard-earned cash when they originally purchased their Power Flow Systems under the same Pre-STC program (albeit at significantly higher prices) that we are now offering to the Maule community.

The PIREPS reproduced below come from members of the Cardinal RG group, each of whom who paid approximately $4,700.00 for their system (and that was AFTER the Pre-STC discount) and from members of the Aviat Husky group who paid a Pre-STC price of approximately $5,200.00 for each of their systems:

“This system is ABSOLUTELY worth buying.  It completely changed my Husky into a fire breathing dragon!  Seriously!

Fuel burn is DOWN in all types of flight.  Cruise speed is UP ON LESS FUEL!  Throttle response is immediate and dramatic........ the slightest movement of the throttle produces immediate power!”
- Mr. J.C. Kantorowicz / Aviat Husky A1B / N770AM / Power Flow Customer since: August 17, 2010

“Improve performance for flying in Wyoming and Idaho mountains.
I now have the compatible performance of a 200 HP Husky.
This is an affordable increase in HP.

I have improved my POH takeoff distance by 367 ft .
I have improved my Manifold Pressure by 1-2 in for given power setting.
I have more confidence that my plane meets the challenges of mountain flying.” -

Mr. Stan Dardis, Aviat Husky A1B / N156AA / Power Flow Customer since: February 7, 2011

Takeoff at light weight, solo, 20 gallons of fuel on board, 4750', calm wind and 72 F. Impressive acceleration, off the runway as if into a 10 knot headwind, climb more brisk than before but not quite sea level performance. This is good, as I rarely get to fly down low, so when I do it's "Holy cow this sucker climbs!".

At 7000', 64 F, flew a box at 2600 rpm and almost full throttle (maybe a 1/4" back) with speed on each leg between 117 and 120 knots. Wowser!! This is with 26" Goodyears. I've never seen 120 knots with the Husky is calm air in level flight at this altitude.

At my more normal low cruise of 1900 rpm, 21" MP, a nice solid 105 knots leaned to 5.7 GPH. . . . All-in-all, a very nice improvement to the Husky - - thanks Power Flow!
Mr. John Morgan / 2005 Aviat A1B Husky / N94HY / PFS Customer since 08/2010

Yesterday I was able to test my Husky with the new Power Flow Exhaust installed against a known quantity. My Husky is a 2004 A-1P and my friend has a 2006. We have flown formation together many times. Our planes fly exactly alike with the same power settings when it comes to speed and climb. . . .

We flew two trips together yesterday. Mine with the PF and his stock. We did a formation take off with me leading. We climbed at 2,500 rpm, full throttle and mixture full rich from a 350' msl airport and 50* F temp. I climbed at 85 mph IAS and he climbed at 75 mph trying to keep up with me. He was unable to keep up with me in the climb and was flying 10 mph slower.

On our first cruise test, we flew at 5,500' with the power set at 2,100 rpm and full throttle and 11 gph fuel flow. I was much faster than he was and he could not keep up at all.

On our return trip he led the formation at 3500' and the power set at 2,500 and 25" of MP. I was able to stay right with him with my power set at 2,500 rpm and 22.5" of MP.

This indicated to me that the PF Exhaust performed as advertised. . . . I feel we gave the system a fair test since my friend and I had flown together so many times in the past. There is no question that the PF has added performance to my Husky. 
Mr. Jack Threadgill / 2004 Aviat A1B Husky / N62DF / PFS Customer since 08/2010

We could go on almost indefinitely but you probably get the picture!

It is worth noting that since the original Pre-STC programs were launched for the above airframes, a total of 61 Husky Customers (10% of the FAA registered aircraft) and 158 177RG Customers (18% of the U.S. total) have now upgraded to our system.  We believe these numbers offer strong validation of our philosophy of working together to make a widely appreciated upgrade available to performance minded pilots.

Of course, you are the best judge of whether or not our system: a.) Works as intended on your airplane; & b.) Is worth the admittedly premium purchase price.

With Power Flow’s industry leading 60 day money back guarantee, the risk is entirely on us.   If the Power Flow System fails to live up to your expectations, or if you just don’t like having all that extra horsepower, you have the option of returning it to us for a full refund of your purchase price.

In this situation the only downside is in doing nothing at all and letting this unique opportunity to secure a more reliable, longer lasting and better performing Power Flow Tuned Exhaust System for your Maule slip through your fingers.

To avoid that dismal fate, and if you haven’t already, we invite you to complete the Pre-STC Agreement and return it to us at your earliest convenience.  The sooner we reach our required minimum of 35 depositors, the sooner everybody will be able to enjoy the benefits of Power Flow’s robust, reliable “Bolt-On Horsepower” Tuned Exhaust System for their four cylinder Maule’s.

Thank you for your time and for your interest in our products.  We look forward to working with you as we bring this project to fruition.

All the Best!

Jim Shafer

Performance and background information:

Many Maule owners have asked if a Power Flow Tuned Exhaust System would be available for their aircraft.  Owners have cited a desire for better exhaust longevity, reduced noise and improved performance.

Over the past few months and with the invaluable assistance of Maule Air, Inc., Power Flow has worked to design an exhaust system that would fit within the cowling of both the taildragger and nosewheel versions of this iconic aircraft.

Designed to work with both the Lycoming O-320 and O-360 engines, the Power Flow Tuned Exhaust for the Maule incorporates all of the same design features that have been part of Power Flow’s widely acclaimed design since 1999.   Each individual “header” is designed to be free to slide in and out of a close tolerance slip joint to allow for engine vibration and cylinder expansion and contraction.  The cabin and carburetor heat will be separate but contained in a single, central collector assembly where additional sealed tubes provide substantial radiant heat sources.   The length of each header is tuned to the correct length for optimized gain in performance, and all four headers are approximately the same length.

The Power Flow Tuned Exhaust System also incorporates a muffler/tailpipe that is designed to be non-obstructive.  This allows the exhaust gases to pass down the muffler tube where sound is absorbed through Power Flow’s special muffler insert.  The muffler is attached to the rest of the exhaust system through 2 ball joints with a support rod attached to the engine mount.  The muffler will exit through the existing rear cowl flap on the left side of the aircraft. 
Power Flow’s Tuned Exhaust System weighs approximately 6 pounds more than the original exhaust system.

Improved performance was a key objective of Power Flow’s design team.  Carefully documented flight tests were conducted with a full engine analyzer and showed impressive results as compared to flying with the original (stock) exhaust system.

Flights were conducted at the same weights, using the same pilots and techniques and with outside air temperatures within a few degrees of each flight.

Here are some documented results, corrected for outside air temperature:

True Airspeed in MPH @ Fuel flow:
1000 Feet MSL:
Power Setting                Stock exhaust:           Tuned Exhaust         Difference    
24 inches/2300 RPM        125 @ 12.2 GPH        131 @ 12.55GPH       +6 mph / +0.35 GPH

4500 Feet MSL:

Full/2300 RPM                139 @ 10.35 GPH     145 @ 10.6 GPH        +6 mph / +0.25 GPH
24 inches/2300 RPM         135 @ 9.6 GPH       142 @ 9.8 GPH          +7 mph / +0.2 GPH

8500 Feet MSL:
Power Setting                Stock exhaust:           Tuned Exhaust         Difference    
Full/2500 RPM                139 @ 10.15 GPH       143.5 @ 10.2 GPH   +4.5 mph / + 0.05 GPH
Full/2300 RPM                134 @ 9.05 GPH         138 @ 9.3 GPH       +4 mph / + 0.25 GPH

Fuel Burn Comparison / Economy Cruise / 8500 Feet MSL:

Stock Exhaust:
Full/2300 RPM                134 (115 indicated) @ 9.05 GPH (average)

Power Flow
Tuned Exhaust
20.1 inches/2300 RPM         134 (115 indicated) @ 8.2 GPH  (saved 0.85 GPH at same speed)
The average rate of climb increase from 1000 MSL to 8500 MSL was 12% faster with the Power Flow equipped aircraft with the mixture set at full rich and climbing at 90 MPH.   The gain in performance improved with altitude.

Further details, pricing and the terms, conditions and discounts available for initial deposit holders can be found on our Maule product information by clicking here or going to: http://www.powerflowsystems.com/products.php?cat_id=20&pid=63.

Power Flow Systems, Inc. is the leading designer and manufacturer of FAA Approved, high performance exhaust systems for General Aviation aircraft, with over 4,350 systems shipped worldwide since 1999.  The company provides a 60 day money-back guarantee, as well as a 2 year/500 hour warranty.

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