Tuned exhaust for 4 cylinder Maules (?) In development

[Powerflowsystems]

Rob,

Let me start out by stating that no exhaust system can be totally immune from cracking. We have over 4300 exhausts out there flying worldwide in all manner of environments and I can assure that the problem rate with our exhaust systems is a much lower rate than the "typical" exhaust. When careful attention and compliance with our mandatory instructions to lubricate the built-in slip-joints (one of the features to defeat stress and therefore cracks) is done and noted in the logbooks at each annual and if the propeller is within normal vibration limits, then that rate becomes even lower. If someone can show me the evidence that all things were truly as they state and show that it was installed per our instructions then we will take care of them. Full stop.

Without knowing the specifics of the cases you cite, it is difficult to truly address.

We fully back the exhaust with a 2 year/500 hour warranty if it is installed and the propeller is dynamically balanced.

The exhaust system was adopted by Diamond aircraft on two different brand new aircraft models and since has shipped over 500 units. We have multiple customers who have purchased a Power Flow for their aircraft, later sold the plane and then bought another aircraft and came back to us for another Power Flow for that model. If we really had a problem that is a significant as is inferred in your email, why would we have aircraft manufacturer's adopt our exhaust or have repeat business?

The Maule exhaust system has not only 4 independent slip joints (one per cylinder) but will also have 2 ball joints for the muffler/tailpipe so allow as isolation from both engine vibration and airframe interaction as possible.

Our 15 years of dedicated focus and expertise in exhaust design gives us high confidence that the Maule exhaust will be as durable or even more durable than any of our other products and we will stand behind it.

In talking to Dawley and my IA, your Power Flow exhaust's still crack and have to be repaired just like the antiquated Maule system. I even looked at one of your systems installed on a Cessna Cardinal that had a long crack that needed to be sent out and repaired and they followed your maintenance schedule to the letter.

My initial interest in your system was to avoid the aggravation and expense of continually dealing with cracks, but yours appears to crack as well.

Could you please address the cracking issue, and are you making any changes that could lessen the possibility.

I really want to see you guys succeed with a better option for us Maule drivers, but until the cracking issue is fixed I have zero incentive to purchase a Power Flow System.

Thanking you in advance................Rob

[MAU MAU]

Hello Darren and thank you for the reply -

It is more than obvious that your Power Flow exhaust is better than what we currently have on our 360's, and I am sure many of your customers have seen the benefits on their own aircraft.

Like many Maule owners I am just sick and tired of the never ending welding requirements and was hoping that if I coughed up 5K I could say good riddance to my muffler cracking woe's.

Best regards..................Rob

[andy]

Since the cracks develop at the welds in the muffler system, what about a muffler system that has ball joints instead of welds? Maybe the header pipes could run straight down to ball joints on the top side of a horizontal manifold on each side with one ball joint takeoff on the bottom of each side for the muffler and tailpipe. That would be a lot more ball joints but if it significantly reduces the cracking problem, it might be worth it.

[Hottshot]

the pipes on my Old 180 are still going strong as far as I know they were ball jointed and have been since installation I would guess over 800 hours now

[aero101]

The most bang for buck is as WUP says... If you send to Atlee Dodge, they will REPAIR your complete sys and you can ask to modify header pipes to be solid with flanged ends, and do ball joints at tailpipe area, and have rebuild mufflers at same time... Or just do ball joints at tail pipe attach is a tremendous improvement that really slows down cracking issues... cost will vary considerably according to what you have them do...

[DavZeeMXT]

Would the changes to the exhaust from Atlee Dodge need any special approval or is it just considered a repair?

[aero101]

I call them a repair up here... That's why you need to send them your old one...

[rjb]

For whatever reason, Maule is not stepping up to partnering with Powerflow leaving it up to us to fund development of a better muffler for the 180 hp models.

Five of us have committed so far. Atlee Dodge is an alternative if you don't mind your plane down for a while shipping to and from and the promise of extra performance doesn't excite you.

http://www.powerflowsystems.com/news.php?nid=88

Maybe Powerflow will revisit the issue if the FAA acts

The Small Airplane Revitalization Act gives the FAA until Dec. 31, 2015, to adopt changes to Federal Aviation Regulation Part 23, which governs the certification of many general aviation aircraft.

Manufacturers say that a streamlined Part 23 will reduce certification costs and thus the price of new aircraft. The changes should also reduce the certification cost and price of modifications of all types from avionics to airbags and seats to restraints, making it more affordable for owners to install modern safety equipment in older aircraft.

It's a large chunk of change but ...

[Curtis]

Being a past drag racer, I would not spend a dime on a product from hype. I would like to see an actual dyno test by an independent lab on how much more HP that you get from a powerflow exhaust system instead of speculation from the manufacture. In the drag racing world there was always someone claiming their product could make more HP but when asked for facts most of the time there were none. My 2 cents worth.

[st8cop166]

Darren@powerflowsystems, as you can tell from some of the remarks, there is some hesitancy to pay that kind of money for an exhaust system. While it is not your fault that some Maule aircraft experience this cracking issue, we are certainly looking for a solution.

While I know from owning an aircraft with a powerflow exhaust that there was a horsepower increase, at least in my perception of performance, I don't want to keep throwing money at a problem that would just be a temporary fix and I'm sure you understand that. The added horsepower is a bonus. The exhaust repair cost prevention is my goal. Having said that, I've just thrown $8500 in repairs to a Maule that was severely damaged by the exhaust design and there is no guarantee it won't happen again except that the last guy didn't catch it but I will.

As you know as a pilot, aircraft owners and pilots aren't going to take a simple "this is the greatest thing since apple pie" explanation. They want to see pictures, flow charts, design drawings, and performance numbers before they will bite on a new idea. I've known some stupid pilots but I never saw anyone become a pilot because they were stupid . . .if that makes sense.

So, I would ask you to provide as much of the info listed above as you can. The recommendation on a third party testing of the system would go a long way to convince folks it's worth the money. Convince us it's worth the money. I'm probably going to be "in" but I need more info beyond a brochure.

Thanks for your time!

[Hottshot]

We were slightly involved in the AWI pipes and the thing that gets lost in the race is the fact that every time you add more stuff you loose performance in useful load. The AWI pipes added 16# to the nose of the Maule and then the cost was high as well. I applaud Power flow and others for thinking out side the box but the name of the game (at least in my out look) is K.I.S.S Keep it simple stupid.... So I would personally rather have a lighter simple setup to keep my useful load where it makes money and a fat bird makes no money to pay the bills so with that in mind the new aircraft are getting a little thick from a pound here and a pound there now we are at a useful load of 600# from 1000# and we bitch about what we can't do with our planes. Now with that in mind I also would not hesitate to pay the higher cost if it is lighter and the performance is up to par.

my .02 (ramblings and insomnia)

[Powerflowsystems]

As you know as a pilot, aircraft owners and pilots aren't going to take a simple "this is the greatest thing since apple pie" explanation. They want to see pictures, flow charts, design drawings, and performance numbers before they will bite on a new idea. I've known some stupid pilots but I never saw anyone become a pilot because they were stupid . . .if that makes sense.

So, I would ask you to provide as much of the info listed above as you can. The recommendation on a third party testing of the system would go a long way to convince folks it's worth the money. Convince us it's worth the money. I'm probably going to be "in" but I need more info beyond a brochure.

Thank you for your thoughts.

I understand a pilot's hesitation and concern that what we offer will deliver the promised performance. What some people may not know is that we have been making improved exhaust systems for aircraft since 1999 and there are over 4300 flying worldwide at last count. The exhaust system concept isn't new, we just figured out how to apply it to aircraft engines, package it into the cowlings and then make it durable and robust enough to be come FAA Approved. We have done this on 12 other aircraft models and have ALWAYS offered a money back guarantee to help ease the mind about product claims.

On our website we have published a lot of "before and after" performance on the Maule we test flew. This means that we flew the Maule at a known weight and using a specific flight profile and technique. We then repeat and sometimes repeat again. We then flew the Maule modified with the Power Flow Exhaust at the same weights, same profile and technique.

There is a video that we recently posted that shows us actually doing these flights. http://www.youtube.com/watch?v=RIZiadtAntU

On our Maule product page itself you can see additional performance information and download performance charts. http://www.powerflowsystems.com/maule.html or http://www.powerflowsystems.com/images/ ... arison.pdf

We have had many different 3rd parties test and evaluate our exhaust systems over the past 15 years. No, a magazine hasn't tested the Maule exhaust but that is because magazines are hesitant to commit to writing about a product that isn't certain to come to market. At this stage in the game, we have said we need to see enough of the market commitment to tell us that we can spend the high 5 to 6 digits to certify it and bring it to market. Ray Maule has flown in the aircraft and said that he was impressed with the speed gain and that is seemed more responsive.

Post to be continued - I am apparently too wordy!

[Powerflowsystems]

Continuing from my earlier post

Here are just a couple of quotes from "3rd parties" that have seen the exhaust.

"I'm not a test pilot but...even I could tell there was a difference. It was that obvious." Flying Magazine (August 1999).

"Overall, the Power Flow tuned exhaust delivers what the company promises. Though each installation is different, Power Flow is proving that its numbers are honest." AOPA Pilot, February 2002.

"There's often a general skepticism about the effectiveness of STCs, but I have personal knowledge that Power Flow's products work as advertised." Plane & Pilot, December 2007

"...Power Flow Systems offer among the best bang for buck of any mods we've reviewed." The Aviation Consumer, Feb. 2009.

We have literally thousands of our exhausts on aircraft with Lycoming O-320 and O-360 engines with both fixed-pitch and constant speed propellers. I don't want to fill the forum with happy Power Flow customer quotes from similar engine installations, but you can read them on our website or Google us. Look for people that have actually flown the aircraft with a Power Flow.

That last thought is that although I can't know for sure that all the cracking problems that Maule exhaust designs have a history of will be solved, I strongly suspect that they will be greatly diminished if not totally eliminated due to design elements of our exhaust. It is not in our best interests to offer an alternative exhaust product to the market that doesn't provide the improvements in performance and longevity. It is because of other aircraft model's belief in our products that we have succeeded and continue to sell and expand our line today.

I hope this addresses your post.

[Powerflowsystems]

The tuned exhaust for the 4 cylinder Maule is heavier than the original - but only by about 6 pounds, not the 16 as you saw with the AWI.

I think we kept things pretty simple but we also stuck to the formula that has a 15 year track record of success and durability. Hopefully the additional 6 pounds isn't a drawback when considering the increase in utility and performance of the aircraft.

We were slightly involved in the AWI pipes and the thing that gets lost in the race is the fact that every time you add more stuff you loose performance in useful load. The AWI pipes added 16# to the nose of the Maule and then the cost was high as well. I applaud Power flow and others for thinking out side the box but the name of the game (at least in my out look) is K.I.S.S Keep it simple stupid.... So I would personally rather have a lighter simple setup to keep my useful load where it makes money and a fat bird makes no money to pay the bills so with that in mind the new aircraft are getting a little thick from a pound here and a pound there now we are at a useful load of 600# from 1000# and we bitch about what we can't do with our planes. Now with that in mind I also would not hesitate to pay the higher cost if it is lighter and the performance is up to par.

my .02 (ramblings and insomnia)

[Curtis]

Hype and no third party dyno documentation....When racing one thing that I learned was to pay no attention to ANYTHING companies and marketers where trying to sell, unless they could provide evidence of their product. Because, they will sell you an eighteen wheeler full of crap if you would buy it. Another thing that I learned is that most decisions are irrational and based on emotion or fashion.
So, most corporations are counting on hard nipples (and what else hype they can dream up) to influence people to go with the sheep and not question their products.