COMING SOON!! Tentitive ship window July 2026!

Bolt-On Horsepower / A complete replacement of your exhaust system.

FAA approved by STC and for all PA-12/18 aircraft listed below

FMA/PMA Approved for the following models with 150, 160hp, and 180hp Engines. PA-18, PA-18S, PA-18 -105(Special), PA-18A, PA-18 “125” (Army L-2 1A), PA-18S “125”, PA-18 BAS “125”, PA-18″135″m (Army L-21B), PA-18 BA “135”, PA-18S -135, PA-18AS- 135, PA-18-150·1 PA-18A -150, PA-18S-150, PA-18AS -150, PA-19(Army L-18C) & PA-19S.

Our new Piper PA-12 exhaust system is very similar to our Super Cub exhaust that has undergone extensive dyno testing at LY-CON Engine Rebuilding located in Visalia, California. Hundreds of PA-18 exhaust systems have been sold worldwide.

The Lycoming 150 Hp A2B gained 16 Hp or a total of 168 Hp, the 160 Hp B2B produced 173 Hp, 13 more Hp while the powerhouse O360A1A pulled 202 hp, 22 more Hp than the stock OEM exhaust system. Brake specific fuel consumption, BSFC, came down while Hp and torque went up. The LY-CON dyno testing also debunks the myth that removing muffler baffles increases horsepower and torque, at least in LEES´s case it´s different. Removing LEES patented muffler baffles caused a loss of 5 horsepower and 10 pound feet of torque.

The PA-12 is fast becoming an outstanding Alaska Bush Plane. The PA-12 has a cavernous cabin, relatively speaking, good performance and affordable pricing. These are a few of its attractions. Now outstanding performance will make it another highly sought after Piper product with a new and more energetic life.

The exhaust system is the same layout as the ever popular Super Cub exhaust. The only revision to the pipes is the long mount risers that have been extended aft to accommodate the longer engine mount. The PA-12 Short mount models are identical to the PA-18 Super Cub.

Using LEES´s very unique U.S. Patented designs EGT´s and CHT´s are much lower and also better balanced. The cylinder back pressure is much lower and all four cylinders equally balanced to within .05PSI; a vast improvement over stock. Our Equal Length exhaust systems are designed with performance and ease of maintenance as a top priority as evidenced by our outstanding warranty and 60-day money back guarantee. Our PA-18 STC eliminates the AD which required inspections of the muffler every 100 hours for the first 1000 hours and every 50 hours thereafter.

Our new Piper PA-18, Super Cub exhaust is designed to fit 150HP through 180HP engines. The 180HP engine is slightly wider than the 150HP – 160 HP engines. Our US Patented exhaust system is an entirely new design that performs very well and is much easier to install and maintain. The exhaust is routed through individual mandrel bent primary tubes with a wall thickness of .049″, 40% thicker than OEM.

The primary tubes are attached to a dual inlet crossover design muffler that can be easily removed to replace exhaust gaskets, perform cylinder maintenance and inspect the muffler baffles. With this new design the cylinder back pressure is much more balanced and the firing order is being utilized for peak performance. All four cylinders are within .05 PSI versus the original system that has a much higher variance of 1.5 PSI, a huge difference! This equates to more balanced EGT´s. Having individual primary tubes eliminates the hot spots and subsequent material failures of the OEM exhaust.

The muffler baffles are fabricated from heavy duty 1.75″ x.049″ wall tubing result for extended life. Due to the firing order, the baffles theoretically will only see exhaust from one cylinder at a time. The exhaust pulse will actually oscillate back and forth through the baffle. This will decrease the concentration of heat within the baffle.

The muffler AD has been eliminated by AMOC, Alternative Means of Compliance. The muffler can is oval shaped and has more effective heating surface than the factory supplied unit. The wall thickness is also 40% thicker than the original muffler.

The muffler is divided into 2 sections for carb and cabin heat. The carb heat side will supply rear seat heat. The removable overboard tube is a much larger 2.5″ diameter when compared to the stock tailpipe diameter of 2″ and the results are much better exhaust flow. The entire exhaust system can now be removed in less than 30 minutes without removing one piece of cowling or swinging the engine!

This will decrease maintenance costs as well as wear and tear on the cowling, engine mount, cables and related components. Another major benefit is that our system removes the exhaust heat from the alternator, starter and oil sump areas by routing the pipes to the rear of the engine compartment. The stock crossover pipes are in very close proximity to these vital accessories.