Aviat Husky: A-1, A-1A, A1B, A1C-180 with Lycoming O-360

Beechcraft Sport, Sundowner: Beech 19 and 23 series with Lycoming O-320 or O-360

Cessna 172: 172, 172A-P with Lycoming O-320

Cessna 172: 172, 172A-Q with Lycoming O-360

Cessna 175: 175, 175 A-C with Lycoming O-360

Cessna 177: 177 with Lycoming O-320

Cessna 177: 177, 177A with Lycoming O-360

Cessna 177: 177 B with Lycoming O-360

Cessna 177RG: 177RG with Lycoming IO-360 or IO-390

Cessna 180, 185 with Continental Engines

Cessna 182, with Continental Engines

Cessna 205, 206, 210 with Continental Engines

Diamond DA40: DA40 with Lycoming IO-360

Diamond DA40F: DA40F with Lycoming O-360

Grumman AA5: AA5 with Lycoming O-320 (s/n below 641)

Grumman AA5: AA5, AA5-A with Lycoming O-320 (s/n above 641)

Grumman AA5: AA5-B, AG5-B with Lycoming O-360

Mooney M20: M20 B, C, D, G with Lycoming O-360

Mooney M20: M20 E, F, J (201) with Lycoming IO-360 (or IO-390) (original or LoPresti cowling)

Piper PA12 with Lycoming O-320 or O-360 engines

Piper PA18 with Lycoming O-320 or O-360 engines

Piper PA20/22 with Lycoming O-320 or O-360 engines

Piper PA28: PA28-140 with Lycoming O-320 or O-360 engines

Piper PA28: PA28-150, 160 (under s/n 1761) with Lycoming O-320 or O-360 engines

Piper PA28: PA28-180 (under s/n 1761) with Lycoming O-360

Robinson R22: R22, Mariner, HP, Alpha, Beta with Lycoming O-320

Symphony: SA160, OMF-100-160 with Lycoming O-320

EXPERIMENTAL Aircraft:

Glastar & Sportsman 2+2 with Lycoming O-320, O-360, I/O-360, and I/O-390 

Field Approval Required:

American Champion Aircraft / Citabria: 8-GCBC with Lycoming O-360

Cessna 150 Series with Lycoming O-320 or O-360

Cessna 170 Series with Lycoming O-360

Cessna A188 with Continental I/O-520

Piper PA24-180 with Lycoming O-360

Our engineering R&D resources are limited and prioritized to develop and certify tuned exhaust systems for aircraft models that are most prevalent. Currently our exhaust design has been proven on four-cylinder, Lycoming engines as well as six-cylinder Continental engines.  As resources permit, systems for other popular aircraft and engine types will be developed and STC'd. You can let us know that you are interested in an exhaust system for your aircraft by filling out our [information request form]. 

Power Flow Systems does not do field approvals at our facility. Working with their A&P/IA's, several Customers have obtained field approvals to install our system on airframes for which we do not have STC approval.  Please contact us if you have further questions. 

A properly designed Tuned Exhaust System typically increases the output of an aircraft engine by 10 to 20 HP.  The benefits of this increased horsepower will vary by aircraft, engine, and propeller type (fixed-pitch or constant speed).  Please go to the aircraft product page corresponding to your aircraft to see the performance benefits you can realistically expect from a Power Flow System. 

Yes, on a fixed pitch aircraft the PFS exhaust will increase your available RPM for Static (ground run), takeoff, climb and cruise. The typical range is an increase of from 30 to 130 RPM. The average fixed pitch aircraft sees an increase of 60-70 RPM.

On a constant speed prop, the PFS exhaust will not increase your available RPM. If you set 2500 RPM with your prop control, the engine will regulate at 2500 RPM.  As your engine will be making more power than before, the blades will be driven to a higher pitch resulting in higher rates of climb or faster forward airspeed than you saw with the stock exhaust.

When leaned correctly, a Power Flow equipped engine is able to reduce its fuel consumption by up to 2.5 gallons per hour. If you fly faster or climb faster than before, you may burn more fuel. With the Power Flow you can choose to fly at the same speeds but will find that it requires less throttle to do so, therefore saving fuel. Many flight schools and clubs use our system and have successfully saved 1.1 to 1.9 gallons per hour.  Please refer to individual product pages for more accurate fuel savings numbers. 

Our system is manufactured with stainless steel tubing that is 40% thicker than most stock exhausts, but EGT probes can be mounted in the exact same manner as they were in your previous exhaust and will operate normally. 

We recommend that you install the probes in the same location as before or in the probe manufacturer's recommended location. All probes should be installed the same distance from the exhaust ports; otherwise temperatures may not be accurate. If the probes are installed in a different location than with the stock exhaust, a different reading may occur.

Power Flow recommends the use of engine monitors. Drilling holes for the EGT probes does not void the warranty or money back guarantee.

The types and amount of improvement that you will see depend on the aircraft and the type of propeller configuration (fixed pitch or constant speed). Please refer to the individual product pages for the specific ranges for each individual aircraft. Below is a general explanation between constant speed and fixed pitch improvements. The numbers stated may not be valid for all aircraft.

For a constant speed prop application, the Power Flow exhaust will allow you to generate the same amount of power as before, using less throttle and lower Manifold Pressure. As compared to the stock exhaust system, if you set the same power settings with manifold pressure, mixture, RPM and Fuel flow, you will ultimately generate more power and higher cruise airspeed. Constant speed equipped aircraft report a top airspeed gain of between 3 and 11 miles per hour when measured with the throttle set at wide open (full). Your fuel flow may be higher than you are used to because your engine is generating more power than it ever did before. As a result of greater power available at the prop, your aircraft will climb at a greater rate than stock.  An O-360, constant speed aircraft reports an average 200 FPM increase in rate of climb at the same airspeeds.

For a fixed pitch prop, at cruise, airspeed is directly related to RPM. During each rotation of a fixed pitch prop, the prop can only pull the aircraft forward as far as its effective pitch. If you generally cruise at a specific engine RPM, say 2300, the prop turns at 2300 RPM and still provides the same airspeed. You will note that it doesn't take as much throttle to achieve that 2300 RPM, thus reducing fuel consumption (usually by 1 - 2 gph). 

You can utilize the extra RPM our exhaust provides to increase airspeed, but you would have to allow the RPM to increase, which will, of course, increase the amount of fuel burned (usually by around 1/2 to 1 gph).  While not usually necessary, if higher cruise speed is your primary goal, you may consider "re-pitching" your propeller. 

In climbs, your engine turns at a faster rate and therefore you climb at a faster rate. The typical fixed pitch C172 customer reports an average 150-225 FPM improvement in rate of climb

Yes. Most of our customers have reported an increase in service ceiling of up to 5,000 feet. The average gain is about 2,500 feet, depending on how big of a gain the PFS exhaust provided you. Power Flow Systems, Inc. does not guarantee a specific increase in the aircraft service ceiling and it is highly recommended that you evaluate and test your aircraft's performance prior to counting on a particular gain or service ceiling. 

Yes and No. There are several reasons behind the "distinctive" tailpipe: performance, heat concerns, durability, etc. In April 2005 we announced a revolutionary new look to our product: the short stack.

The Short Stack exhaust is available for all Pipers, Grummans, & Cessna 172 and 177s. For Pipers and Grummans, there is no performance loss from the use of the short stack as that system's design is of the same length as the original classic. We were able to find an engineering solution to routing as much of that tubing inside the aircraft cowling as possible.

For C172 and C177 aircraft only, the Cessna short stack comes out of the cowling at exactly the same angle, length and diameter as the stock exhaust. As it is a shorter length than the ideal tuned length, the average Cessna sees only about 90% of the improved benefits as compared to the Classic original exhaust. If the look of the exhaust is a concern and you don't need to squeeze every ounce of power out of the exhaust, then we recommend the short stack. 

If, on the other hand, you want the maximum gain possible (i.e.: if your aircraft is on floats, &/or you typically operate in high density-altitude environments), then the Classic does give you the best "Bang For The Buck". Key differences between the Classic system on a C172 are listed as follows:

C172 RPM gain on the ground with classic: 75 RPM; With short stack: 69 RPM

C172 gain in average rate of climb with classic: 225 FPM; With short stack: 200 FPM

C172 gain in service ceiling: with classic 4500 feet; with short stack: 3000 feet

C172 ability to operate lean of peak: with classic is excellent - able to remove up to 300 RPM from engine smoothly below 65% power; With short stack: moderate - ability to operate approximately 50-100 RPM lean of peak smoothly.

Based on our flight-testing we have determined found that drag caused by the tailpipe is more than overcome by the thrust coming out of it. During testing we have also examined the use of fairings. Our testing indicates improvements in cruise speeds as well as engine temperatures from the use of exhaust fairings. We have an exhaust fairing available for the Classic C172 exhaust. Cessna C177 (Cardinal) and Grumman owners can also use the existing fairings on the market with our products, however, some realignment may be required.