PowerFlow is it worth it

[PTK]

The one thing threads like this do is they remind me just how much I love my 201! Keep it going! 

IMO the M20J is the epitome of the perfect airplane. Refined and perfected in Kerville. It does not need any "speed mods" precisely because its so perfect the way it is! No pf exhaust no lopresti cowl, nothing! 

So instead of spending thousands upon thousands for a dubious knot here or there, I put a small fraction of those $s into proper maintenance keeping my J in tip top shape and of course for 100LL to enjoy it as much as I can. 

Did I mention I absolutely love my Mooney? 

[ArtVandelay]

There are speed mods for the J too, unless you have 205 version. My J has them, installed by PO, I wouldn't have. Anyone install the PF on a IO-390, that combo might give 10 knots.

[mike20papa]

When they build 'em out of titanium, I might pay $4K. 

[MyNameIsNobody]

15 hours ago, aaronk25 said:

It's not just a performance mod, it a cooling mod too, taking 35f or so off head temps.

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You said in another old thread you burn more fuel with the power flow.  Yes or no?  Cooler temps with higher fuel burn and a little more speed.  No thank you.

[MyNameIsNobody]

I have read that the 4 banger and PF are NOT the combination that delivers gains of larger displacement engines where value is greater.  I am not pontificating.  I did my research and made my decision.  I fly LOP.  If I wanted to go 5 knots faster...and more.  I can.  I don't need a 4K exhaust to achieve speed gains.

[PTK]

On ‎6‎/‎23‎/‎2016 at 0:01 PM, Bob_Belville said:

I have an E model. I don't know how much to credit the PFS but my IO360 is very balanced. I did a Savvy Lean test recently and found that the engine is very well balanced averaging under 0.3 gph gami spread for 7 scans. The engine runs smoothly with all cyls 50+ LOP and a LOP mag check passed easily. I have to credit fine wire plugs and the PFS for some of that. 

No PFS, no fine wires, no gamijectors, no BS.

All stock... isn't it beautiful!!

[PTK]

On ‎6‎/‎22‎/‎2016 at 8:09 PM, FlyboyKC said:

... is the Powerflow a reasonable option for the money ~$4k ...

IMHO No!!

[Bob_Belville]

14 minutes ago, PTK said:

No PFS, no fine wires, no gamijectors, no BS.

All stock...
 

Peter, I'm confused by that graph. The EGT peaking @ 10.0 gph is 25% higher than where my IO360A1A peaks. (LOP 10.0 GPH is 75% power.) SAVVY SOP: GAMI Lean Test: Cruise @ </= 65%; From 100+ ROP slowly to rough and back to rich.....And SAVVY wants several very slow scans to make the analysis meaningful. One GAMI spread datum point is nice but inconclusive in isolation.

Here's the SAVVY report from my recent GAMI spread test. GAMI spreads from 7 sweeps through peak ranged from 0.1 to 0.5.  (I also ran mags check @ 50+F LOP. Engine ran smoothly on either mag for 1 minute tests.)

GAMI Lean Test Satisfactory

Sweep #1 Flt 2016-06-06 15:24 Time: 00:21:06-00:22:30 EGT3 peaked at 8 EGT4 peaked at 8 EGT1 peaked at 7.9 EGT2 peaked at 7.7 GAMI spread is 0.3

Sweep #2 Time: 00:23:24-00:24:22 EGT2 peaked at 8.5 EGT3 peaked at 8.5 EGT4 peaked at 8.5 EGT1 peaked at 8.1 GAMI spread is 0.4

Sweep #3 Time: 00:25:13-00:26:12 EGT3 peaked at 7.9 EGT1 peaked at 7.8 EGT2 peaked at 7.8 EGT4 peaked at 7.8 GAMI spread is 0.1

Sweeps 4-7 were at 0.2, 0.3, 0.4, 0.5

Observations

Savvy likes to see a GAMI spread of 0.5 GPH or lower. The average for these sweeps is in the range that we like to see for smooth LOP operations.

[Oldguy]

Have to agree with Peter on this one. This is from the week of July 4th. Tempest massives, standard injectors and stock exhaust. And ~1450 SMOH.

[Bob_Belville]

Just now, Oldguy said:

Have to agree with Peter on this one. This is from the week of July 4th. Tempest massives, standard injectors and stock exhaust. And ~1450 SMOH.

8.5 gph makes more sense than Peter's 10. but see my reply to him.

Is this graph typical or one off? Are you a paying Savvy client? Have you performed their gami spread check and got them to do a flight analysis? 

[slowflyin]

The original question- Is it worth it?   Seems like a low-risk proposition.   Put it on and try it.  If you don't like it send it back.   That was my thinking when I was on the fence.  I figured all it would cost  3-4 hours labor on both ends.   My stock exhaust needed inspection anyway so I was really down to 3-4 hours of labor if I didn't like it.   I didn't pay $4000 either.  Bought in advance and saved a considerable amount.    I'm fairly certain I can sell my stock exhaust and recoup some funds.    I've chosen to keep mine.   Others may have chosen differently.   I've heard stories of someone who knew someone who knew someone that returned theirs.  I do believe some are returned.  Anyone here that has exercised that option?

[PTK]

Why are you confused Bob?

This may help you...

http://eaavideo.org/video.aspx?v=2274677932001

[Oldguy]

52 minutes ago, Bob_Belville said:

8.5 gph makes more sense than Peter's 10. but see my reply to him.

Is this graph typical or one off? Are you a paying Savvy client? Have you performed their gami spread check and got them to do a flight analysis? 

Bob,

No, this is not a one-off, but it was at 10,000' running LOP. My typical GAMI spread is from 0.3 to 0.0 when travelling cross country and usually keeps my CHTs under 365. I am not a paying Savvy customer...yet. I expect prior to my annual later this year I will sign up, run the tests and let them give me a report before dropping it off at the shop.

I think I am the beneficiary of a well maintained plane for the years prior to my ownership. While I am the 9th registered owner since she left the factory, one group had her for 17 years and kept her in tip-top condition thru 2009. The owners between then and my buying her in 2013 used some top notch MSC's for maintenance as well. 

[Bob_Belville]

4 minutes ago, Oldguy said:

Bob,

No, this is not a one-off, but it was at 10,000' running LOP. My typical GAMI spread is from 0.3 to 0.0 when travelling cross country and usually keeps my CHTs under 365. I am not a paying Savvy customer...yet. I expect prior to my annual later this year I will sign up, run the tests and let them give me a report before dropping it off at the shop.

I think I am the beneficiary of a well maintained plane for the years prior to my ownership. While I am the 9th registered owner since she left the factory, one group had her for 17 years and kept her in tip-top condition thru 2009. The owners between then and my buying her in 2013 used some top notch MSC's for maintenance as well. 

OG,

Apparently our IO360s are normally pretty well balanced. The GAMI injector folks told at SunNFun that their injectors are seldom needed with our engines. My CHTs and Oil Temp were high when I bought to plane 4.5 years ago but are now very good. Baffle seals, a couple of tubes sealant, cowl flap repairs and adjustment, PFS(?)... At any rate I now can climb in the summertime w/o seeing 400 CHTs or 200 OT and cruise temps are much better than that.  

[PTK]

Hopefully this is less confusing for you Bob? Same flight rich to lean.

[Bob_Belville]

33 minutes ago, PTK said:

Hopefully this is less confusing for you Bob? Same flight rich to lean.

Peter, yeah, that looks more like on would expect for a typical IO360. If you haven't done so recently you might try the SAVVY LOP test which involves multiple, very slow passes through the peak zone with the EDM set at most frequent sampling.  http://www.gami.com/gamijectors/leantest.php 

[aaronk25]

Ok the reason most PF customers as well as I saw a drop in CHTs is because there is more heat extracted with each exhaust stroke as the PF creates a vacuum or at least less back pressure aft of the exhaust valve which in turn evacuates more hot exhaust gasses.

With the PF the plane is very very marginally faster, 1-2kts at a given fuel flow, but it will run 5-6kts faster than the stock exhaust if more fuel flow is applied.

I installed the PF because my muffler was cracked and instead of spend money say $1,100 repairing the old system I got all new for $3,800, with a modest performance improvement.

The heat is just as effective as stock but only if the additional header heat kit is installed.

And no there is no spread sheet I don't care that much wether another pilot wants to install the system or not and if you don't want to spend the money I could care less.

Just passing along my experience and I also could care less if PF sells 1 or 100 or no kits based on my review as they have yet to offer me a percentage of sales. If you like it great if you don't ok no skin off my back.

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[Bob_Belville]

3 hours ago, aaronk25 said:

Okay, the reason most PF customers as well as I saw a drop in CHTs is because there is more heat extracted with each exhaust stroke as the PF creates a vacuum or at least less back pressure aft of the exhaust valve which in turn evacuates more hot exhaust gasses.

With the PF the plane is very very marginally faster, 1-2kts at a given fuel flow, but it will run 5-6kts faster than the stock exhaust if more fuel flow is applied.

I installed the PF because my muffler was cracked and instead of spend money say $1,100 repairing the old system I got all new for $3,800, with a modest performance improvement.

The heat is just as effective as stock but only if the additional header heat kit is installed.

And no there is no spread sheet I don't care that much whether another pilot wants to install the system or not and if you don't want to spend the money I could care less.

Just passing along my experience and I also could care less if PF sells 1 or 100 or no kits based on my review as they have yet to offer me a percentage of sales. If you like it great if you don't okay no skin off my back.

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Aaron, I had not heard that there is a supplemental "header heater". I don't need it in NC but I'm glad to have you confirm that there is a difference.

As PFS is quick to point out, there is no aerodynamic changes associated with their tuned exhaust. So any performance improvements come from incremental power capacity. That should affect take off performance and TAS at higher altitude.

 

[aaronk25]

So what happens is similar to a tuned exhaust in a race car or motor cycle. The header length and position of the exhausting header is located next to the header of a cylinder that is next to be exhausted so basically the one headers rushing gases create negative pressure next to the header about ready to be exhausted which in turn creates less back pressure and gets more hot exhausts out lowering Chts and making more available room for intake air (O2) for the next charge.

The stock system has all the headers dumping into a muffler so the more exhaust released the higher the pressure the next header/cylinder has to over comb in order to evacuate the hot gasses.

It's just like the poop tank on a over shore boat. Open the valve (no pump needed) and the water rushing past the discharge hole sucked the poop out. In the case of PFS the previous header creates the negative pressure. It's pretty simple and surprised the stock configuration doesn't utilize this basis of design.

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[PTK]

Way too much theorizing and hot air is being expended for what amounts to...well...a negligible amount of hot air!

By my calculations some are making too much to do about ~13.5 cubic inches per cylinder volume of gas!  And that's on a good day! It's closer to half of that practically.

So to answer the op's question if it's worth it. Well you decide. Do you think a few cubic inches are going to give you any measurable and reproducible performance gains and are they worth 4K?! If your answer is in the affirmitive the word "gullible" comes to mind!

 

[jetdriven]

43 minutes ago, PTK said:

Way too much theorizing and hot air is being expended for what amounts to...well...a negligible amount of hot air!

By my calculations some are making too much to do about ~13.5 cubic inches per cylinder volume of gas!  And that's on a good day! It's closer to half of that practically.

So to answer the op's question if it's worth it. Well you decide. Do you think a few cubic inches are going to give you any measurable and reproducible performance gains and are they worth 4K?! If your answer is in the affirmitive the word "gullible" comes to mind!

 

How did you arrive at 13.7 cubic inches of volume per cylinder?

[PTK]

22 hours ago, jetdriven said:

How did you arrive at 13.7 cubic inches of volume per cylinder?

Byron, according to powerflow, a standard exhaust leaves behind about 20% of spent gases and, their exhaust allows as much as 95% intake of pure fuel air. So at best that's about a 15% delta.

Transferring this to our IO360 that's ~54 cubic inches or ~13.5 per cylinder.

[carusoam]

I think I get it....

1) the PFM is expensive.

2) the HP benefits are real, and small.

3) people tend to choose the PFM at replacement time.

4) few people have added the PFM on the basis it generates more power.

5) the power that is generated is a plus, but it requires more fuel.  The PFM is the enabler.

6) PTK is always going to be here.  He makes you think. He draws you in.

7) using foul language is way to express a weakness. Your valid arguments get lost in the mud. Avoid getting drawn in. Your logic gets stronger just by maintaining control.

8) heat recovery uses energy.  More heat recovery requires more surface area in the hot exhaust gasses.

9) A muffler that is dumping exhaust efficiently is going to have difficulty collecting heat.

10) flying in the northeast in winter in a NA plane at 10k' is wicked cold!  God heat recovery is a plus.

11) the modern materials and construction used in the PFM, may make it last longer. The original in my C went 40+ years

12) most of us here are using the logic that flying IS WORTH IT.  Applying the same logic... a PFM is worth it, at replacement time if the funds are available...  

Stay calm

keep flying

Following this logic, everyone will be flying a 310hp TN Mooney someday.  It's worth it.

Best regard,

-a-

[mooniac15u]

2 hours ago, PTK said:

Byron, according to powerflow a standard exhaust leaves behind about 20% of spent gases and their exhaust allows as much as 95% intake of pure fuel air. So at best that's about a 15% delta.

Transferring this to our IO360 that's ~54 cubic inches or ~13.5 per cylinder.

At what temperature and pressure? Immediately after combustion the exhaust gases will be at a high temperature and pressure inside a closed vessel. Once the exhaust valve opens the gases will expand due to unrestricted space and relatively lower air pressure in the exhaust system. The expansion will cause cooling as will removal from the hot engine environment. 

[ArtVandelay]

I think I get it....

1) the PFM is expensive.

2) the HP benefits are real, and small.

3) people tend to choose the PFM at replacement time.

4) few people have added the PFM on the basis it generates more power.

5) the power that is generated is a plus, but it requires more fuel.  The PFM is the enabler.

6) PTK is always going to be here.  He makes you think. He draws you in.

7) using foul language is way to express a weakness. Your valid arguments get lost in the mud. Avoid getting drawn in. Your logic gets stronger just by maintaining control.

8) heat recovery uses energy.  More heat recovery requires more surface area in the hot exhaust gasses.

9) A muffler that is dumping exhaust efficiently is going to have difficulty collecting heat.

10) flying in the northeast in winter in a NA plane at 10k' is wicked cold!  God heat recovery is a plus.

11) the modern materials and construction used in the PFM, may make it last longer. The original in my C went 40+ years

12) most of us here are using the logic that flying IS WORTH IT.  Applying the same logic... a PFM is worth it, at replacement time if the funds are available...  

Stay calm

keep flying

Following this logic, everyone will be flying a 310hp TN Mooney someday.  It's worth it.

Best regard,

-a-

When I see PFM I think of the the Mooneys with Porsche engines:

Porsche-Flugmotoren was the official name, maybe we can use PFE?