Category Archives: Bang for the Buck

Power Flow in AOPA news – “Exhausting maintenance: Performance improvements”

Be sure to check out what Jeff Simon with AOPA had to say about the Power Flow Systems Tuned Exhaust by clicking here: Exhausting maintenance: Performance improvements – AOPA

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Don’t take our word for it

So, just how much difference can a Power Flow System really make, anyway?

Well, hopefully the unedited, voluntarily submitted Customer testimonials reprinted below will give you a good idea of the performance improvements you can realistically expect.

As you can see, these submissions cannot be easily reduced to “sound bite” size, so we don’t usually use them in our marketing materials, but I think they are both impressive and of significant value to anyone who may be wondering whether or not one of our Tuned Exhaust Systems would be a worthwhile upgrade for their own airplane:

Cessna 177B Cardinal:


So . . .  In my last email  I said that I was somewhat on the fence regarding my purchase of the Power Flow Exhaust. Well I have fallen off the fence with this last flight! So this weekend I flew to HII -Lake Havasq, from Casper which I believe is around 650nm. It was just myself, lots of gear and every inch of fuel I could jam in the tanks.

Well it took a while to get there, but the Cardinal made it to sixteen five! I set her up for cruise flight and made it in under five hours and a beautiful flight over the Grand Canyon without even a bump-I think that I could of set a wine glass on the glare shield and enjoyed it after tie down- thats how smooth it was! Also I should mentioned that I had to keep pushing her down as she wanted to climb higher along the entire route.

Now get this. I had not planned on making it direct, but with a good tailwind I was able to go non-stop and when I went to dip the tanks there was still ten gallons on each side! I figured a fuel burn of under seven an hour as I believe I can cram three more gallons a side with the monarch fuel caps. Needless to say  I was very impressed with being able to cruise my  fixed gear 177 at 16.5.

So while I think that is impressive it gets even better! On the way home I had even better winds, and thought that I would just plan on 15.5 for the trip home. Well when I got to 15.5 I should of leveled off, but  I had to see if I could get her to 17.5. Well she made it and while sometimes  I couldn’t hold her there and loose a couple hundred of feet, ATC called me once during the flight and said the Transponder was reading 18.2 and did I have the right altimeter setting!

Almost a repeat of the first flight, and when I landed I had 26 gallons in the tanks! So now I am a believer and there is no way that I would of gotten that kind of performance without the Power Flow system.

It took me a while to earn that kinda cash for your exhaust as I am a school teacher here in Casper, but it was worth every penny! So I am slowly healing from my fall off the ” fence” but looking to many more flights in the Cardinal with your great product! And thanks again for your support of CFO! As you know a great owners group!


-Joe in Wyoming – N30661 / 1969 / 177B

Cessna 172 Skyhawk:


I purchased your PowerFlow short stack headers for my C-172N with the O-320-H2AD engine a little over a year ago and ‘can now report “final” performance numbers:

–I now burn about 0.7 gal/hr less fuel. Oddly, the new numbers correspond nearly exactly to the Cessna POH power table, except without the “25-50 RPM drop” due to excessive leaning the handbook recommends (who actually would fly an engine that way, especially at higher power settings?). I am happy with the fuel savings, which more than cover the cost of the extra exhaust system inspection at annual time,

–I’ve added about 1500 ft to my service ceiling. At STP, my aircraft has a book service ceiling of 14,200 ft. However, in the summer on a desert afternoon and with a full load, the “real” ceiling was more like 12,500 ft.

This was the main reason I purchased PowerFlow, and I am very happy, flying as I do all over the Southwest during summers and ‘am also appreciative of the extra ability to climb above well above the Sierras on windy days to avoid rotors,

–the aircraft can generate a given power level at higher altitudes than previously, expanding my flight envelope,

–upon installation, the “old” idle mixture setting proved to be much too high and I had to modify takeoff and landing procedures to avoid fouling plugs for awhile. I suggest you recommend that the owners of new installations check their idle mixture prior to leaving the shop, and

–funny thing, I noticed extremely efficient fuel burn at 50-60% power settings, < 6 gal/hr. This gives me the option of extra range if I need it.

I guess the tuned exhaust efficiency is “peaky?” If so, good, I like the option of extra range and prefer the maximum range possible (which occurs at low power settings), rather than having the efficiency “peakiness” at 75% power.

Nice product.


-Don Ferguson / N737EG / Cessna 172N w/ O-320

         Mooney / 200 HP


I also have the Power Flow exhaust on my M20F. N3463N with an IO360A1A (200HP) fuel injected engine with a 3 bladed prop. Prior to the installation, at 13,000′ the plane would climb at 50FPM and the stall horn would sing while the plane wallowed. Now, at 14,000′ the plane climbs at 150FPM and indicates 110kts in the climb. I’d a gone higher, but it was cold up there. I call that a significant improvement.

In fact, when I departed from Daytona after the installation of my PF, I was startled as the plane rotated off the runway in a much higher attitude than normal. I immediately rechecked the trim, but found all as it should be – except that there was nothing but blue in the windshield. My burn rate went from 10.5gph to 9.5gph. Even aggressively leaning the engine never causes pre-ignition now, and above 10,000′ I routinely see 8.5 gph.

Now, get the wrong mechanic and you can kiss all this and more good bye! The engine is placarded for 20 degrees BTDC, but the manuals indicated 25 BTDC timing is allowable. Give up that 5 degrees and kiss your performance good bye. The same mechanic that reset (sigh) my timing – also screwed up the pre-load on my gear. Bad timing and gear hanging in the slip stream and you might as well get a damn 172.

So, I now fly routinely at the bottom of the yellow arc – higher – longer and cheaper. And this, with a three bladed prop.

-Mr. Tim Proksch / N3463N / M20F

 For Grumman AA5B / “Tiger”:


I recently installed a Power Flow exhaust on my Tiger . . . I have noticed a huge difference in the performance of the airplane, especially with regard to climb.

It has been extremely hot and humid here in the Virginia Tidewater Region, with density altitudes of 2000 feet and more, yet my Tiger took off in a shorter distance (felt like it leaped off the tarmac), and demonstrated a 150+ foot increased rate of climb.

As you know, our planes are not know for being great climbers, and all else being equal, this is not only a big performance improvement, but an major safety factor increase considering taking off with a loaded aircraft and increased density altitudes. Not sure you can quantify or put a price on the safety factor. . . .

With respect to increased maintenance, the mechanic and I discussed the pros and cons before installation, and intend to disassemble and lubricate as recommended at annual time. I think will be a small price to play for the both the increased performance and safety margin.

John Wrenn / AA5B / N74636

For Piper PA28-140 Cherokee:


While my 1967 Cherokee had a 160HP conversion and most available speed goodies, your exhaust system was the single MOST IMPORTANT AND SATISFYING ADDITION to my plane. It significantly altered the whole character of the plane. First, my wife, a non-flyer, noticed the plane “seemed to fly better”. In the first 50 hours after the installation the performance settled out as follows:

Climb performance was enhanced by 100-300 feet per minute from takeoff. For example, we were at 6500 feet with my wife and baggage and Charlotte Approach asked us to climb to 8500 at ATC – we did so, with no hesitation, something we struggled with before the new exhaust.

Cruise performance rose 4 or 5 KIAS at 2350-2400 RPM (50 degrees LOP)

Cruise fuel flow was stable at 7.5 GPH, approximately 1 GPH improvement across the board.

Engine performance, winter or summer, indicated some 10-15 degrees cooler EGT, 10 degrees cooler oil temperature. Oil use, Aero Shell 15-50 synthetic, improved to approximately 1 quart in 10-11 hours as opposed to 1 quart in 7-8 hours previously. I and my wife felt the engine seemed to run smoother.

The bottom line is that the POWER FLOW System WAS A GREAT ADDITION TO MY AIRPLANE AND I WHOLE HEARTEDLY ENDORSE this outstanding product. . . .

– Dr. Kenneth Noble / Former Owner of PA28-140 / N1523J

Mr. Shafer,

We just finished my first full annual after installing your amazing system. And we have performed the maintenance as instructed and my power flow exhaust looks as great as it performs!

I’m sure you hear these stories all the time, but it still amazes me every time I fly. I’m in southern Arizona where the ground is at 4,500 ft MSL and in the summer the density altitude can climb to 7,000+. Prior to installing the system I’d be lucky with a 50-100 FPM climb out. Now I’m 600-1,000 FPM depending on how heavily loaded. Everyone is sure I have a 360 tucked under the hood! I just finished flying back and forth to the local college to get my CFI and my ‘little 140’ out performs the college’s Warrior 160s with ease. I’ll be sure and send them the coupons as the director is considering installing the power flow systems onto their fleet aircraft to facilitate training during the summer.

I was skeptical about purchasing it in the begining (saving pennies as a new plane owner) but it has been the best performance booster to date and I always recommend it to everyone I fly with..

Thank you again for a great product!


Jesse L. Brewington

Of course, we could fill quite a few more pages with similar success stories, but you probably get the idea!

All the Best!

– Jim Shafer