last spring, i think it was cubflier who was going to test the LEE against the Atlee performance muffler. i looked for a thread but couldn't find if indeed he did this and was wondering how it came out? if not, has anyone who has had any one of the exhausts have any comments, good or bad experiences, etc. know this has been covered in the past, but was wondering again as most have had their particular system on for awhile. thanx ahead of time!!
Did anyone do exhaust tests?
- Thread starter 68D
- Start date
cubflier
Registered User
Palmer, AK
I'm actually going to do a test sometime in April.
I did a static test on both the LEE and the Atlee Performance System when I switched from the Lee to the Atlee but because the test were on different days and different DA's I was not confident in the results.
The LEE had 50 more RPM than the Atlee but the LEE test was done at a lower DA so who knows...
This time I'm going to use a scale that measures thrust in addition to testing the static rpm. I'm going to try to capture results on similar DA's but as you know changing an exhaust system takes more time than throwing a light switch.
I'm guessing the results will be close and then you will have to figure the cost benefit, weight difference of 5lbs, noise difference, and cabin heat output into your decision.
Also keep in mind this is just one guy, that ain't no scientist, doing one test.
Jerry
I did a static test on both the LEE and the Atlee Performance System when I switched from the Lee to the Atlee but because the test were on different days and different DA's I was not confident in the results.
The LEE had 50 more RPM than the Atlee but the LEE test was done at a lower DA so who knows...
This time I'm going to use a scale that measures thrust in addition to testing the static rpm. I'm going to try to capture results on similar DA's but as you know changing an exhaust system takes more time than throwing a light switch.
I'm guessing the results will be close and then you will have to figure the cost benefit, weight difference of 5lbs, noise difference, and cabin heat output into your decision.
Also keep in mind this is just one guy, that ain't no scientist, doing one test.
Jerry
Christina Young
Registered User
Andover-Aeroflex, 12N
I would be very interested in these results!
cubunltd
Registered User
Belle Vernon,PA
Didn't do anything scientific yet but I have built several 160hp supercubs and always used the borer 8242or 43 pitch props. on these planes. Last year we built a 160 hp supercub with the lees exhaust and We are using a 44 pitch Borer with good results. take off in 160-170 feet and a cruise of 115 mph. The Pa 18 is the green one on my website and it is loaded with extras. The empty weight is 1200 lbs. so i was impressed with the performance. I also did some testing with Miss Daisy and got around 30-40 feet shorter takeoff with the Lees system. The before and after tests were done in very similar conditions. Plan this summer is to build a thrust meter and do some scientific tests. Tests so far have been seat of the pants and measurements on the runway.
John
I for one recommend the Lees System. the extra weight is offset by the performance increase
John
I for one recommend the Lees System. the extra weight is offset by the performance increase
Christina Young
Registered User
Andover-Aeroflex, 12N
cubflier said:
Jerry -- one thing I meant to ask - was this test done with your LEES that had all the cracks, spewing carbon monoxide and setting off your CO detector almost everytime your started the engine
, or were those cracks fixed prior to the test? Just curious.....How do you like the Atlee exhaust overall? Anything you don't like about it?
Fortysix12
Registered User
RanchAero Grand Vista, Brooksville
How do ya'll connect up the plane during a pull test and what kind of scale?
cubflier
Registered User
Palmer, AK
Christina Young said:cubflier said:
Jerry -- one thing I meant to ask - was this test done with your LEES that had all the cracks, spewing carbon monoxide and setting off your CO detector almost everytime your started the engine
How do you like the Atlee exhaust overall? Anything you don't like about it?
Christina,
I took off my LEE system for the reasons you mention. It had only one crack at a known stress point and the guys a LEE repaired it no charge. It was an opportunity to see if the Atlee system might offer comparable performance with 5lb less on my nose. My cub seems to be a bit nose heavy so this is of concern to me.
Overall I like both systems but if one outperforms the other it will be on my engine regardless of the weight penalty.
The LEE is quieter, and makes more heat. It clutters my engine compartment with cool looking pipes. I like room to work since I tinker. I think LEE's fix is a good one and will take the crack issue out of the equation. I did get a good CO tester over the whole deal.
The Atlee make a lot of noise and I would rather do without the noise. I have a Maule for that stuff. The Atlee performance seems close enough to the LEE to make the cost difference a question. Then again it's only money.
If the LEE does not outperform the Atlee I will stick with the Atlee because of the weight diff.
Jerry
Fortysix12
Registered User
RanchAero Grand Vista, Brooksville
I am looking forward to testing the pull of my E2D with the Sutton exhaust and HC pistons. I will testing with the Stock 150 Sensenich. What would be a good number?
bushmaster
GONE WEST
GLENBURN,ME
1500 lbs Ha Ha! we all wish!
Homerrhoid
Registered User
Homer Alaska
I had to chuckle to see the cub, wound up at full power, tied to a truck. It's aimed at the fuel pumps!
It reminds me of a friend doinf high speed taxis in a cessna 140- no pilot's license. He lost control and found himself headed for the fuel pumps at Fort Yukon Airservice in Fairbanks. He pulled back on the yoke and took to the air. After flying in circles for 30 minutes, he got up the nerve to land and did so successfully. That was at the Metro gravel strip- it was a huge strip which probably saved his bacon!
It reminds me of a friend doinf high speed taxis in a cessna 140- no pilot's license. He lost control and found himself headed for the fuel pumps at Fort Yukon Airservice in Fairbanks. He pulled back on the yoke and took to the air. After flying in circles for 30 minutes, he got up the nerve to land and did so successfully. That was at the Metro gravel strip- it was a huge strip which probably saved his bacon!
moneyburner
FRIEND
Western Washington
DW said:
HA! That's just what I was thinking!!
I've had my LEES exhaust for about 150 hrs now. So far no problems. In fact I think I gained about 100 rpm relative to the stock muffler. (180 hp)
But where are these cracks/stress points showing up? Perhaps I need to examine the system a little more carefully. Are there any suggestions regarding brackets that may prevent the stress points from developing into problem areas?
But where are these cracks/stress points showing up? Perhaps I need to examine the system a little more carefully. Are there any suggestions regarding brackets that may prevent the stress points from developing into problem areas?
cubflier
Registered User
Palmer, AK
KingCub said:
There are brackets that wrap around the muffler that separate the shroud from the muffler. As I recall the crack formed on the center one at one of the welds. The fix is a slip joint at this weld.
Unless your LEE is an old one you should already have the fix incorporated.
I now own an ST90 which is a handy tool for determining the integrity of the muffler on the fly.
Jerry
It don't look to bad you get use to it. it sure does clean up the extra crap behind the engine. i did cut some of the exhaust off i left 6 inches sticking out. it looks good. one guy cut the min off and it was to short, your suppose to leave at least 3 inches coming out of the cowling.
cubflier
Registered User
Palmer, AK
Me and Crash did a test of stock vs Atlee vs LES. Our conclusion was there was significant difference in the cost, weight, and amount of noise each system produced and that's it.
Our test was done in a manner that would eliminate confusion between DA effects and measurements of both thrust and rpm were taken. The results were the so close that we concluded that there was very little difference between systems.
A possible flaw in our methods might be from the fact that we tested the difference between stock and Atlee on a 180 hp cub and the difference between Atlee and LES on a 160 hp cub. Again no difference but can one conclude that all three are the same? We did.
Jerry
Our test was done in a manner that would eliminate confusion between DA effects and measurements of both thrust and rpm were taken. The results were the so close that we concluded that there was very little difference between systems.
A possible flaw in our methods might be from the fact that we tested the difference between stock and Atlee on a 180 hp cub and the difference between Atlee and LES on a 160 hp cub. Again no difference but can one conclude that all three are the same? We did.
Jerry
:lol: 
