Bolt-on HORSEPOWER? Tuned Exhaust Installation - Power Flow SystemsJun 06, 2021
and that's the stock
exhaustyou see the problem with these right here they leak all that's good we're not even in very cool that's great zero zero 22 degrees celsius sitting at v and doing thousand feet per minute with three people on board 901 Cross return is approved for our call to base. The crosswind turn is approved, not another. We will await your call, which is why we have conducted a thorough investigation. instructor who loves the sky sharing it with those around me and using it to see the world from a new perspective flying may seem super complex but my mission is to promote safe practices while enjoying the beauty this world has to offer subscribe to climb the cockpit of future adventures this is aviation 101. new orleans clearance on departure hold 2 000 feet chelsea and i have
flown november 80991 all the way from san marcos texas to daytona beach florida home of
systemsthe last two v videos on youtube cover the two days of ifr cross country flying it took to get here and they include a really good insight into my creation process and how I work through my planning when it comes to long trips definitely check out those earlier videos here on aviation 101 and the full edits of those flights are in the cabin club too I've been looking to get a
powerflow for our cessna 172 for eight years since we bought it and i started talking about power flow
systemsin 2019 about how i could really embrace the benefits of your
tunedexhaust system for youtube and we finally got it done in early 2021.
This video will actually cover four days of footage before the test flight with the original. stock exhaust installing the power flow and after the test flight on the new exhaust and a quick summary of the data we collected on both flights in that time we also installed a Challenger i air filter kit It's basically an air filter high performance which is stc and we also did a dynamic balancing of the prop which doubled the power flow exhaust warranty to 24 months or 500 flight hours and that actually proved my prop was very unbalanced to begin with indeed the El Challenger air filter will help the engine inhale better and power exhaust flow will help the engine exhale better.
We started this video at the powerflow factory in Daytona Beach where we got some insight from Jim Shafer on how it was tuned. the exhaust does this when the engine is rated they do it on a dyno with four inch neutral stacks that put absolutely no load on the engine as soon as you remove those neutral stacks and put in whatever exhaust system is going to restrict the power to up to a certain point and what the standard designs on most general aviation aircraft actually reduces the power rating to between 25 and 35
horsepowerand what will the power flow give you most of that loss again makes up about 95 percent of the loss, so instead of losing 25 to 35
horsepoweron a 160 horsepower engine, you'll make 157 to 158 horsepower with a flux-equipped engine. power you're not increasing the rated horsepower beyond rating level you can't do that but you're getting a lot more than the rated horsepower engines have been delivered to the prop ok so basically the gist is that the stock exhaust on these old engines are not tuned for performance and efficiency and since that was not a design priority they actually restrict airflow exhaust out of the cylinders and thus restricting the fuel charge airflow of fuel air into the cylinders basically the engine isn't breathing as freely and efficiently as it is capable of with this old set of pipes and a chelsea big can muffler darren tillman of powerflo and i are going to take november 809,991 over the atlantic ocean hence the inflatable life jackets and d We are going to run a full performance profile to gather data on how my engine performs with the original exhaust.
We will pay close attention to the revolutions per minute of the engine. RPM. Fuel flow, which is measured in gallons per hour. Cylinder head temperatures chts. and an exhaust gas temperature reading for each cylinder egs. I learned a lot of things on this flight. One element is the relationship between the chts and the egts. It is really important to determine the efficiency of the exhaust system. we are going to do a normal power flow test profile which is where we want to establish the performance differences between the stock exhaust system you have now and once you install the power flow and we will ideally do it the same conditions, the same exact weights, same pilot techniques, same types of air speeds, so the first thing we do is climb from sea level, so what we're going to do is because we're close to the ocean. going a couple of miles offshore that way we don't have a real lift effect from the ground because we're over the ocean we also avoid a lot of traffic and the idea will be that we'll go down around two thousand eight hundred feet positioned so that we can do a climb straight ahead with no turn unless we have to because of traffic and we're going to go straight up from a thousand feet to 8,500 feet that's fine and what we'll do is once we get through a thousand feet. going to slow the plane down to v and set v and go to full power keep pace v and so between 700 feet 1000 feet that's your time to fine tune your pitch we don't start timing until we hit a thousand hit a thousand let's get going a stopwatch ok every 500 feet you're going to give me a you're going to call me hey approaching 1500 approaching 2000. once we reach that ideally one of us will figure out who can read the time or better we'll tell the time and you're going to tell me airspeed avg you've been holding up well i'm going to record airspeed, outside air temp, rpm and i'm going to try and record as many chd, egts and fuel flows as possible hopefully the camera will back that up correctly so what we'll have when we're done we'll have time slices every 500 feet ok we're not going to record rate of climb we're going to calculate it ok just easier yeah because it's inst vintage instead of true average absolutely once we get to 8,500ft we will transition to a cruising speed profile so what is your favorite rpm you like to cruise at?
I like 2450. 24.50 that's a great number for the 172. also perfect rpm for power flow that's ok because the non-super secret problem is the tuned exhaust system has totally max rpm response it's at 24.50 perfectly you've accidentally been perfect for the test right there so what we'll do is we'll go up to 8500 feet and we'll start with a lower power setting for a lower cruise speed say 2300rpm we'll set the engine to 2300rpm and we'll lean it we'll lean using your normal technique and then we'll need a couple of other techniques one of the other things you'll see with power flow is that you can actually lean the engine towards peak safely and effectively and with the same output dramatically cooler temps so we'll get our baseline data for that we'll pick 2450 and also do a wide open throttle number because at the end Finally, more power should mean more rpm and up to 8,500 we can do it safely, then we'll go down to 5,500 feet, repeat those numbers, okay, are you ready? yell airspeed and I'll record as much as I can okay okay I'm going to try and hold 80 here and full throttle and we're going to hold this track about three five zero well done Alright we're set to 80 full throttle power cruising 1000 now 82 knots we got it all good outside air temp rature I'll go with Celsius 17 2460 rpm fuel flow seems to be 14.6 good number cruising 1 500 now 52 seconds 81 knots now because it's carbureted, fuel flow will stun a little bit you know jump a little bit so we look at it and try to take a weighted average catch it three thousand three minutes 49 seconds 81 knots copy that outside air temps 12 degrees back to 24 40 now your egts are awesome alright yeah they are definitely a lot lower now after the carb done there is 3,500 4 minutes 56 seconds 82 knots cruising 5,000 8 minutes zero seconds 80 knots copy that eight degrees ok cr using seven 13 minutes and eight seconds 80 knots ok getting ready to cross 85 17 minutes 51 seconds 81 ok we'll call it 80 knots 80 knots 7 degrees celsius 470. i write things down to the best of my ability 9.0 ok you can level it at 8 500 ok So what we'll do is once you've gotten your setup and you think we're stable at speed and the engine's stabilized, then we'll start a timer.
We will wait at least three minutes before recording the data. Okay, let the plane establish its balance. We've been keeping 82 knots all this time. I'm going to record 82 okay time is three minutes our fuel flow leaned towards you uh it gives us five eight to six two outside air temperature here is six I have it all on record it's alright uh the oil temps uh sitting there at 181 thats really good go ahead and top up nice and uh your new rpm target is 2450 start to lean very slowly ok let's see all these exhaust this now is look sea all exhaust gas temps something is going to lean first and its looking to see which one is going to lean first now you can feel the power coming out we are on the leaning side right now it's ok just stop there for a second let it keep dialing down now we've lost 130rpm you'll need to adjust your hole well you're doing a good job you're ho According to your pitch we want to maintain altitude so we're going to lose a lot of speed.
Now, this indicator is confusing because it's like it's really your peak, no, not really, but this is where you feel most comfortable. like this is a good cruiser yeah i mean just feeling the engine it feels like it's a little on the skinny side ok but it feels right you're not like oh my gosh something's trying to escape from cover. no, not at all. there are no parts that come apart, so a hallmark of a really good incline, especially on a peak, is how close they are, for example, to each other, that's fine, and as your smart device says there's a difference in 58 degrees between hottest and coldest that's more normal for a carbed stock exhaust I got you when we get the power flow there I hope we see a difference well we should have it's been about three and a half minutes our speed, as you predicted, went back up to around 93 93 what I would call 93 to 94. we'll give it a little buff.
Your fuel flow is working pretty well. dht 337 1417 number two is 323 1434 349 14 61 38 1398 ok so you can get rich on the plane then gradually take us down uh we're probably going to play with some clouds at 5500 hope not let's see if you can catch us to 5500 and we'll do the next round of 5500 tests set up with the power flow system, the maximum available rpm will generally increase by 100-150rpm so if you're looking for a particular power setting, say 2450, it will be take a smaller percentage of throttle available to get to that 2450 rpm level is a smaller percentage of 2700 than 2500, which was probably your peak flow of rpm before power, so the engine revs less quickly, you're not getting burning, no you don't burn as much fuel in crui se flight because you can get the same power with a smaller percentage of throttle we fly the rest of the altitudes and power settings and gather all our data on darin's performance profile then head back to Daytona Beach International where I then began removing the old stock exhaust to make way for the
installationof the power flow tuned exhaust system outlet from daytona 942 tower foxtrot i'll go ahead and load dirt in there so it'll be less work for us and that poor thing too short four four zero eight number one or just two five left cover option before let's float a little bit get that gun from sideslip now we're just going down here in effect I usually let the plane tell us when it's ready to stall attack sensor lifted off daytona tower change my frequency one two zero point seven hole short row and two five left ok we can make whiskey see the problem with these right here they leak all many times in the stock exhau st you will get cracks in this can here especially if the plane is used for training this is what is under the cover , this is our manifold assembly the idea behind the tuned exhaust system is a couple of things the number one balanced length so each cylinder should have a length of balance, but it must also have the correct diameter, so it is both thediameter as length what matters.
Turns out it's three and a half feet per cylinder. so we can totally get it to the correct length but now this section is a big radiator these are sealed tubes the only weld is attaching the end plate here these four tubes stick out through this end plate they are welded to the plate final. you can see there's like a star in the middle for the stars to weld together and then we weld the rest of it up and then do something that most other exhausts don't do we send this out for a particular heat treatment it's called annealing it's an annealing to bright vacuum so everything is shipped and under a heavy vacuum it heats up to I think 1825 degrees and then for 20 minutes it stays there and then quickly shuts off so this stuff is as smooth as it could be every time you turn it on your engine, it's functionally stress relieving, but the annealing takes all the stress and all the stress out of this thing being built, this is forming, the welding is going on, and it brings everything back into solution so there's no a particular hard spot or stress.
Period there it's all homogeneous now okay so what we have here is a Cessna 172 power flow tuned exhaust system with our short stack option so this would be here so these headers go they're relatively short , they go here and they go through the long section, this other side, these really long tubes, we're trying to get the length right because they're going to go into a shorter length of this tube. so we've done our best to achieve that, that's why those tubes are so long, we're either trying to balance the length or trying to get the length right because that's what the tuning system has to do to work properly. and that's where you can see this section here is carb heat this section here is cabin heat this is the same part it has a shroud the tuned exhaust design allows the engine to develop a higher percentage of its rated power we don't we are doing nothing the engine is not designed to do we just let it run the way it was designed to run and not restrict the flow which the normal standard exhaust does on most ga planes it is a bottleneck in engines and most people can feel that because you can feel when you hit the throttle it stumbles a little bit usually before it starts to open up and put out all its power so this is the exhaust, what is this? it actually stays two inches across, but inside of it where these screws are, that assembly that goes up here is a sound chamber, it's a fader, it's a technical term, actually it's called an unobtrusive fader because the gases don't have to go through any path they just continue out.
I'm going to show you what it looks like inside. What is there is one of these. I see, I can see right through it, so the gases go through and out. The path hasn't changed for them, but they're running through the sound chamber, so here's my cheesy demo, but it'll work. I'm going to take off my mask so you can hear it. This Is My Voice This Is My Voice This Is My Voice This Is My Voice This Is My Voice is a pretty effective damper but doesn't get in the way the way a traditional exhaust system would atta, gases have to diffuse through your tubes and holes and wear out this will eventually wear out but what wears out is this stringy outer layer that has to 400 to 800 hours l Based on our expectations we specifically designed the exhaust system to be easy to maintain so which when that happens, it's held on with four nuts and
bolts, you get the new one and you put it in, you align it, you drill the new holes and it comes with new hardware. you're done in half an hour from start to finish, don't send the muffler in for a rebuild or anything, ok so we're getting ready to do the test flight, now we'll put on our life jackets against the wind. it's nice it's starting out of the west right now and we've got some cloud cover here over the airport in Daytona and then we've got a little bit of cloud cover to deal with over the ocean so we're going to take a little bit of a different approach how we're going to do this climb and descent profile because we need an unbroken constant airspeed climb pretty much in a straight line, so we're going to find a long stretch of ocean that has clear skies or as clear as we can get it above and from there we will start the climb at around 700 feet again start the timer at mil and hold that airspeed all the way very excited to feel the difference in the plane and hear the difference in the engine very excited to see what the guys are going to do egts and chts and fuel flow fuel flow is what i will be very excited about if we are able to dial that back while putting out the same can amount of energy that we could before so that everything is installed, we have finished with the preflight filled with gasoline we are going to dress with our survival equipment, life jackets and everything, since we will be on the water, let's do this test flight after the
installationI'm very excited to see how it feels good the mixer is rich Let's get ready to climb here.
I think everything else looks good. You remember the sequence and the prompts. Right here it looks a lot better that way yeah let's go south that's good we're going south that's okay we're stabilized at around 81.82 that's okay as we go through that 1000's start the timer please ok power up set time 1000 feet 81 knots and we're going to cross 3000 3 minutes 30 seconds 82 knots butt rate of climb has now flowed dramatically it's only gone up one degree ok on the last 500 feet which is about where we normally see so this condition represents something like a worst case scenario I'm in the rocky mountains or a hilly area I have to keep doing the sustained climb correctly so you're really demanding a lot from the engine we're running ahead of the stock exhaust even though it's four or five degrees celsius hotter today and much more humid five thousand feet seven minutes 48 seconds 82 knots copy that your honda cylinder has now just approached the brand 400 it's 404 but by no means a particularly hot concern right we're running almost 30 seconds faster at altitude so far great and that's with worse temps the worst temps so there's more performance if it would have been ideal and we could have done it all like this but that didn't work for us and okay okay to cross 6000 that's 10 minutes and 12 seconds 80 knots is holding that rpm number for quite some time still at 2480 which is where it's been for 2000ft which is really impressive now his chds are starting to pull back as his power density all of that is going down a bit and now the chd is starting a bit of an ascent but only very little because you just touch the mix, you raised the mix about 40 degrees on that egg in the egt, just enough that you know, hey, you gotta get yourself out of a bad situation, there's a little more in there, right? 8 500 feet 17 minutes 17 seconds 80 knots copies that so in the end about 30 seconds faster at altitude even though it started out significantly good reasonably warmer normally when power flow is turned on we anticipate seeing more air in the cylinder and typical Also the fuel flow will increase a bit with the throttle setting wide open however on this climb we did show a 20 to 30rpm gain in lower fuel burn with the power flow not much two or three tenths and yet it was a 20 to 30 rpm higher number, uh, and it was three degrees Celsius warmer on average.
I had my own video showing that the most appropriate segway is to be vigilant, yes all I could say is perfect for what I am doing that well. Keep an eye out particularly for your exhaust exactly right. Every once in a while, when someone really starts pulling some funny pranks. I know and then they say oh please stop you're killing me I'm sorry you're feeling under pressure yeah that's good let's go full throttle now it's okay because that's what we're going to do. start from full throttle anyway we might as well go full throttle and play around with so let's go ahead and get full throttle and lean to top power as you've seen and then after that we're going to play around with the mix to see how far we can take it with the engine right and I would like you to start slowly leaning the engine.
I want to see how many rpm we can get out of the engine with no problem, so when you start to affect the shift, just stop, wait a moment or two, like right there, so wait a second. let it all even out watch what happens to the cgts they will level out and start going down yeah I see how would you characterize this? go a little richer so let's play richer and just give it a second because you can see how much that affected you yeah so I think there's a sweet spot somewhere in the middle what I want to try and do is I want to get us to 2450 because if I'm doing it right we should be able to go Thin the peak and save fuel and cool the engine and get the same air speeds of course I'm trying to show the camera with this all the different things that will play while flying. and do a lot of offroading so don't be afraid to do this kind of thing because number one says if you want the engine to run cooler lower your cylinder head temps lower your oil temps and you'll be all right . it doesn't matter what for example all you're doing is cooling the air you're cooling with additional air instead of excess air instead of excess fuel that's all you're doing um and right now this is dealing to say hello, we think you have seven degrees, tilt a peak.
I'm not sure I'd buy that, but you have a carbureted engine, so this is really cool. We are now within a third of less than a 40 degree difference. I think we might have finally found our sweet spot so it really wasn't 26 10. We ended up starting at 25 30. We have i t went down to 24. well i was trying to get to 24.50 and now 24 30. so previously on the rich side of the peak we were burning a gallon an hour or more one to one point two gallons an hour huh the only other get would be a wide open throttle ok plz now its a good thing you are getting more net rpm um previously you could see such time 26.90 that's pretty good when it's been steady it's been 27 30 yeah 27 28 to be exact yeah so I mean that's solid stuff okay does it make more power clearly?
Do you know that you can go ahead and turn around if you want to and you can go back and descend and all of that so your plane can actually get up and go? That's really good daytona tower skyhawk eight zero and then another straight on two five left hey zero nine on a daytona left to clear line two five left clear to land eight zero now another but what's the other it's going to happen because your engine should be a lot more responsive so if you ever need e if the engine dies a bit it doesn't have to happen at all i got two five left and touch down no delay accident travis on shore wildlife 476 right at the end and touch down without delay november not around one turn not another one 901 spark one two zero four one able left traffic two five left will call crosswind turn left traffic 1204 in the squadron look at the fins up one that's good we're not even in very cool that's great five hundred dollars has increased productivity at the end of sanity airport one two zero zero 22 degrees Celsius going down to v and doing a thousand feet per minute with three people on board and a crosswind turn approved for a call to base crosswind turn approved now another let's wait for your call and you've got your circling practice good I was going to say that you were just telling me about how to get the most out of the power in one lap and there it was i have both the traffic and the age of the view romeo perfect so you're number four following you south now your base rolling eight to five left number four all right track is ours i was coming idle tracks done oh sure go ahead if you are developing chts in the 400 450 500 range that is seriously affecting the longevity of your engine and with this power flow in an engine properly tuned, you usually see three 380 max. even climbing so it's important that you keep it in the healthy operating ranges most of the time you can make it's full rated power at those rpm and on those engine configurations uh without stressing the engine and you never find yourself in a situation where The one that is really trying to get more out of the engine than it is capable of producing will get rated power at or very close to it in all aircraft operating regimes.
Darren spent many hours behind the desk compiling a summary of our performance numbers. before and after on these flights all these data have been corrected for temperatureand pressure and this is what we saw time to climb from 1,000 feet to 8,500 feet above sea level was 34 seconds faster with power flow at wide open throttle at 8,500 feet produced 6 knots more true speed of air with the power flow exhaust but with the same fuel flow as the stock exhaust which right there tells me the engine is running much more efficiently at wide open throttle at 5,500 ft with the power flow installed produced 30rpm more than stock exhaust an extra five knots and we were burning 1.5 gallons an hour less that's a perfect example of the engine breathing better the added lean ability with the power flow exhaust is also super awesome poor stock exhaust rich off peak at 8,500 feet at 2450 rpm produced 97 knots at 7.1 gallons per hour, while the power flow tuned exhaust allowed us to run lean off peak as well giving us 97 knots but now at gallons per hour at the same speed for 1.1 gallons per hour less the oil was also 9 degrees colder and all cylinders were reading colder too which made it all finally click for me was when Darren He described the egt and cht relationship to me in simple terms. heat has been transferred from the cylinder heads to the exhaust so lower chts, higher egts, this combined with better intake through the challenger air filter means the 80991's engine is breathing better than ever.
Better breathing means better cooling, better performance, and a longer-lasting engine. I've been thinking about installing power flow for years and my first hand experience with the system and the company showed me that I should have done it a long time ago. They have a really amazing product line backed by data, the company, and everyone. in it is a big thank you to power flow systems for making the process so easy and using their expertise to bring a much needed product to the legacy general aviation fleet, you can learn more about power flow by visiting the link found in description and full versions of these performance flights are available at aviation cockpit club 101.com if interested seeing them in the video below chelsea and i desperately trying to contact daytona clearance We fly over NASA, visit the factory of an experimental aircraft manufacturer, and take a few days to traverse Florida, where Chelsea gets more firsthand. ifr experience as we head to pensacola subscribe and turn on notifications so you don't miss out on upcoming content definitely leave a comment below i would love to hear your feedback on this video and all the technical content we had in it and until next time everyone who know the drill, stay happy, healthy, current and most importantly stay proficient, we'll see you in the next one, fly safe.
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