Actually Enhances Aircraft Performance
Leading Edge Exhaust Systems, LLC (LEES) says it's tested its
Super Cub exhaust system -- and the results are "impressive."
First introduced two years ago, the certified LEES Super Cub
exhaust system replaces the original Cub exhaust that has been
plagued by an AD, requiring inspections of the muffler every 100
hours for the first 1,000 hours and every 50 hours thereafter. The
all-new LEES system eliminates the AD, saving owners and operators
time, money and wear on the equipment.
When LEES founder, Dane Wagner, first introduced the new system
he refused to make any performance enhancement claims. Recently,
however, LYCON Engine Rebuilding (lycon.com) located in Visalia,
California, inspired by testimony from numerous customers of
increased power and performance provided by the LEES exhaust
decided to conduct independent dyno testing of the exhaust above
and beyond what was required by the FAA during certification.
LYCON released the independent test results to LEES and they are
impressive. Dispelling the common myth that aircraft engines
produce more power with the muffler baffles removed, the LYCON
tests prove LEES Cub exhaust performance enhancement with baffles
installed. According to LYCON, a 150HP Lycoming engine leaned to
peak RPM lost 2HP and 7lb/ft of torque with the baffles removed and
at full rich it lost an additional 3HP and 3lb/ft of torque. The
total loss recorded without baffles was 5HP and 10lb/ft of
torque.
The LEES system with baffles, installed on a 150HP Lycoming
O-320-A2B engine by LYCON, produced 16HP and 27 lb/ft of torque
more than the same engine equipped with a stock exhaust system. A
test performed on 180HP Lycoming O-360-A1A engine by LYCON equipped
with the LEES exhaust gained 22HP and 20 lb/ft of torque.
Wagner credits the test results of the all-new system to
improved exhaust flow and balancing of the exhaust back pressure on
all the cylinders. The new LEES system removes the stock crossover
pipes, which results in a much more balanced back pressure (within
0.05 PSI, while the stock system varies by as much as 1.5 PSI) and
reduces the heat exposure to the oil sump, starter and alternator.
The new risers are all mandrel-bent for optimum flow, are equal
length, and are 30 percent thicker than the stock system.
Each cylinder has its own separate exhaust pipe connecting it to
a new dual inlet muffler, which means the exhaust risers and
gaskets can be removed on an individual basis without removing the
cowling or swinging the engine. The new, dual-inlet muffler
incorporates two patented baffles which are made from thicker stock
than the original. This translates to increased part life and a
larger, more effective heating surface area for the muffler.
"My primary goals were to improve the engine's efficiency,
eliminate the muffler AD, and reduce maintenance down time," said
Wagner. "But I'm pleased with the LYCON test results."