A series of tests were conducted to determine the effectiveness of various modifications to a Cherokee 140. These tests took about 90 hours of flying, and were observed and reported on by writers from many publications, including Aviation Consumer, AOPA Pilot, Flying Magazine, Plane and Pilot and others.

The plane, with no mods had a max cruise of 128 mph, and a cruise of 118 mph at 10,000 feet. It took 23 minutes to climb to 8500 ft.

After the mods, the max cruise had increased to between 149 and 153 mph, the 10,000 ft altitude cruise was 147 mph. Time to climb to 8500 ft was reduced from 23 minutes to 14 minutes!

(All of these numbers were subject to some variation due to atmospheric conditions, but can be considered accurate to plus or minus 2 mph. Time to climb varied by about one minute from test to test under similar conditions.)

Here is a spreadsheet of the gains:

Summary of ALL Flight tests on Cherokee 140

pERCENTAGE GAIN:

	Max Cruise 8000 D. Alt.		Economy Cruise		Rate of Climb avge. to 8500 Ft.
	MPH	MPG	MPH	MPG	FtMin
Stock	128	11.6	120	14.5	326
Flap & Aileron Gap seals	133	12.1	126	15.2	368
GAIN	5		6		42
Full LFS Kit	144	13	137	16.5	418
Inc. SpeedPants
GAIN	16		17		92
	MAX.	MPG	ECONOMY	MPG
	SPEED		CRUISE		Climb
FULL LFS KIT AND	152	13.8	140	17.9	555
POWER FLOW Exhaust
TOTAL Performance gain	24		20		229
PERCENTAGE GAIN	19%		17%	65%	70%

The above were not taken from just one flight test... they were taken from over eighty flight tests and averaged!

Your plane not a 140? The results will be very similar, as the wings are essentially the same! The only reason I use the 140 example is because I had one available for years. We have tested all the different PA28's, PA32's and PA34's with similar results.