X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=PbaBeRpd c=1 sm=1 tr=0 a=Wec96TlhXvBbTLcyALRmzA==:117 a=x7bEGLp0ZPQA:10 a=Fee85h93u3AA:10 a=y4yBn9ojGxQA:10 a=8IjSFGYmQxEA:10 a=Ia-xEzejAAAA:8 a=3oc9M9_CAAAA:8 a=pGLkceISAAAA:8 a=0qqORytXAAAA:8 a=7g1VtSJxAAAA:8 a=cCHiArm5vy40T7fn_U0A:9 a=q_nJGWPohiL7hnkr:21 a=c0T-6gfD7KnpZ739:21 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=ciY2bB1sCqjV-H2Itl8A:9 a=J25zmR8Q-U09pIlj:21 a=11_XhzIUaHQ9mAVE:21 a=jvKd2psGEPm1F1WP:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=Nj1bhqyGrdl6Az3_ctNx:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "lehanover lehanover@aol.com" Received: from sonic314-14.consmr.mail.bf2.yahoo.com ([74.6.132.124] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 617379 for flyrotary@lancaironline.net; Fri, 07 Aug 2020 21:12:02 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.6.132.124; envelope-from=lehanover@aol.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1596849105; bh=+sVbWBJZiS3R7iMO8GUaFkoHbHCHq1zySPh2X0V3ezY=; h=Date:From:To:In-Reply-To:References:Subject:From:Subject; b=XOBt9PPDZK2a04SXVNTIIlIFOMVhyKCrHBSNSQxL7qhw2OGVelGE5F+bFbmvKJpPby2U7S3SBX30NA0rSWEoXAQ4MakztYiMeLRBWjkewS7e4T8/Bs/6M7uhn0NMnQWHbebKgrTyzQEw3GMp28NslVsu1mZ7ni+vZjaTU8c2jTXOIAxGvV0Dwr52MEUF2bN8TfsvYQUKm9+/1vrIK5a4tAAjVomYM+IcSpNNk6yeeXpwcMZf7fYnupJjQyTSc8C0ZFD/qXSZpy2azTtfeb6a2FcVCFXeitdeFUHuu+H6ziBwIMyKxcIFmhK1hB8fxH45JXTN/eWxgQRlhVbup2uM2Q== X-YMail-OSG: NsfxWZAVM1lOpE0S.Eo6rDmnU5Bx40rQ3LAUiDqEfDrG7OztaSRVsa9RfXsNPtg hd4Jv_eJWwZgTnk_AP23fzu7ABQftwZkCnoGh.1dBqlIEQbJi3mH9b4eM_mO2wltM_kQgZSHViDx He8b9fYdLfPnnju5Cxi8KJoTmPfRQ0oRQbbed46DcbEsE8inPLkpC5HrzvqkxvLIU9gRtY5bQqkv 1tunCFatvV0X80Ki64E0x8BQhsT.u1LQd_oLWG0lpH4JUe_jUTZt4_owx9D2_fd36WHUp0tnhcAb kJNY2OQq8lvBuYMdM5FMtGzr9s.urbaH7YR_TxWyk6IcvTg1KYh9nV39NWwGmJw.ihLHqYERxto_ .44Qrs5ViwED5Bq.t1I3HOSv1D_C7h_VgNVKAyUqgMYsqpWd_aZsc_MOoUHcWvLlwLrT2dS5HEQF NJNvvbCeGNHAT_KOWg6uIf1k2kW4zgeM1NoC1qFDzSkbyRszuoZgDSf0rJuVdpqwxVUOsKvl8SxR gMpZtgwQczWohfw.EpBUQUolyofin1g9lvqzhjzhJneNQhp4mNq88noIj3ZIGFZ3oLKQ6zOOIpQb g4XLyuFD1FMPkt1ua7ZSLQCjfqXL6Wzu6kH8_byDqCsC0sn8b0RaEMKOQZzwjWofe1gIGrfZzJo2 GS.sk77jMTQyY5KZSRvD2lUR5YtzEMxsHdwBjYNd2FC.H7cEFqG3qys1gc6nmC59T6MGCMZNjtBI MdUyXqsbUo1uLnKg9VLyG9h6G7syuDLn414lz4b4mgHzNmyEtUygdfdi9BrG3QCzCKheJB6cVzB5 lOd6Vkn6Vy9GBOiMfmsyyaELNDDiRe3NDJ27znSCgatcM36qxmBR8NC.AbQfoThLpqcf6EsNBJCi GGdQ1fnT3aqYe6PdyJetixvQHsEmOQfx5EMoQUwtAo4miwP_zLY7Dmq3xtI7m30Mk.vMSi5CO0H2 zkVrOoZxFhBmcUNpfpZP.GYvfOIrzMwDVbN73_rI4Vz8XQ6Twx0uYTtwC39mkBvLA5b0gmNOGmuO zPSdDyx1zKpIzZmuGPtnqRufNKoheRmx8JbNjyIIRebCdqX_6xC93cIYJ3X5drejmqc_tmmJofhA mbKCDFpcXbpf7z5kM9K_mkE4SJmazzDVbBN41v.A8NhC1E5YWKIKqJ4kLYCrjtOU44TVCtZojVSR HFUnjQTfqQ8V9IcoMeQgpI80qaPSonvTZAHQ_cBuMf3fAOb1Hy5bJLImw9mwZxBZtiPbqrhy6vyV TwmjR4.AM75Vn34Zt2M0AKOjLHdiIPiTN_0j1nmk7Tg02dVVImVkX3hERI5GcmaArCRZl5.Ja7Mm RalNYO7_aJRsFa8U_0GG2HiB9kwCqShVTM7Z9spsYhQiefh_MChyKv6uTDPBYeO5fyQ5eAsnB Received: from sonic.gate.mail.ne1.yahoo.com by sonic314.consmr.mail.bf2.yahoo.com with HTTP; Sat, 8 Aug 2020 01:11:45 +0000 Date: Sat, 8 Aug 2020 01:11:40 +0000 (UTC) To: flyrotary@lancaironline.net Message-ID: <727603821.1204267.1596849100769@mail.yahoo.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: Dyno Sheet MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_1204266_790105307.1596849100763" X-Mailer: WebService/1.1.16436 aolloki Apache-HttpClient/4.5.7 (Java/1.8.0_252) Content-Length: 40741 ------=_Part_1204266_790105307.1596849100763 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Not your fault.=C2=A0 =C2=A0 I am old and easily confused....... After each dyno pass, you compare each number recovered near or in the inle= t tract wherever your fresh air supply is recovered. So as to establish the= "Weather" or air conditions the engine is "seeing" These are large printed (size C formats) years back. It is now probably a s= pread sheet for very quick calculations. For example you are looking for so= me help at the bottom end to help get out of corners a bit better. You chan= ge idle jets closer to best power at 7,500 RPM then add a bit of accelerato= r pump. I made movies of the gauges for review. In two days of testing (for= this one problem) we have many different inlet air temps. Many barometric = pressures and many humidity readings. So each pass produces a different raw= HPreading. You look on the SAE chart for the number you just recovered and= follow the column to the SAE correction number temp. or pressure or humidi= ty and you fill in your home made form with the "NEW" SAE multiplier.=C2=A0= Since all of the charts start at sea level each SAE multiplier will reduce= the raw HP number. But, all of the passes are now in the same format as al= l of the variables are removed. I could get 2 or 3 good readings using the = movies. The throttle is always wide open and the test RPM is controlled wit= h a water brake load cell. In most cases your great idea will cost you HP. but every so often Jackpot.= ...4 corrected HP.=C2=A0 =C2=A0 =C2=A0Modern dynos have this stuff built in= to their computers so the numbers you see are already corrected to sea leve= l. In olden times they were not. Lynn E. Hanover=C2=A0 =C2=A0=20 In a message dated 8/7/2020 8:29:40 PM Eastern Standard Time, flyrotary@lan= caironline.net writes: Sorry Lynn. My apologies those figures @ 9500, 7500,6000 and 4500 are altit= ude. Didn=E2=80=99t click that they could also be read as RPM. Sorry! Again thanks for the expertise, those things you mention re flow make sense= of the anomalies. Please excuse my ignorance - SAE tables? Right, so convert those numbers ba= ck to sea level. Can you explain this for me Lynn? Much appreciated.=20 Steve > On 8 Aug 2020, at 8:08 am, lehanover lehanover@aol.com wrote:> > The impossible is possible................> > Along t= he way to tuning success you will find that a specific combination of facts= may appear and disappear within a few RPM.=C2=A0 Such as induction tube le= ngth VS exhaust system harmonics/back pressure. Every RPM would suggest tha= t a specific tuned intake length would be ideal. See the Mazda winning 4 ro= tor and its adjustable length intake runners.=C2=A0 Exhaust back pressure m= ay be high at one RPM and nonexistent at another. The whole reason for disc= onnecting the intake and exhaust=C2=A0 in the Renesis among other things is= to get the tuning down to some form of normal (Meet California UHC). Havin= g no overlap is a giant step in that direction. The poor exhaust shapes hel= p pollute the incoming charge a bit so as to reduce combustion temps and pu= ll back Oxides of Nitrogen. I have seen movies of fuel air flowing backward= s in an intake runner.=C2=A0 =C2=A0 When you record what appears to be faul= ty data do not discard it and then see it again the next day.=C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 When you make a change....make it a big one so you can= see which way that one took you. Never make more than one change.=C2=A0 Us= e the SAE tables to take all of the data down to sea level. Before you comp= are two data sets.=C2=A0 It is a steep learning curve......but it will come= to you.=C2=A0 I had a fabulous Stuska dyno in my shop for years.> and a fl= ow bench. I never did learn all I should have.> > Fixed pitch props (In eff= ect) reduce pitch as air speed through the disc increases.=C2=A0 The sugges= tion that you turned up 9,500 RPM gives me chills. What would the tip speed= s be then?> > You can get above 10,000 RPM with 13-B rotors but they must b= e very light and you must look inside after every race because the tend to = crack when that light. Note that the Renesis rear main bearing is two diffe= rent diameters to allow for that standing sign wave that forms in the crank= .=C2=A0 Nobody uses Fram filters or lets friends turn over 8,000 RPM> Lynn = E. Hanover> > In a message dated 8/7/2020 6:48:47 PM Eastern Standard Time,= flyrotary@lancaironline.net writes:> > Hi Charlie and all> > On the four r= uns - Speeds were:> 147 KIAS 21.6=E2=80=9D @ 9500 WOT> 136 KIAS 18.2=E2=80= =9D @ 7500 (Not WOT)> 160 KIAS 24.8=E2=80=9D @ 6000 WOT> 165 KIAS 26.2=E2= =80=9D @ 4500 WOT> > Prop hub is Airmaster 3 blade electric with Aerotek Bl= ades> > On looking over the 4500 ft run:>=C2=A0 =C2=A0 As RPM steps up from= 5500-7250 (in 250rpm inc) over 9 mins (OAT 49)>=C2=A0 =C2=A0 Temps gradual= ly build from 172/154 to 198/171 (Oil/Water)>=C2=A0 =C2=A0 Fuel Flow goes f= rom 14.5 peaking at 16.2 (6750) before ending at 15.8>=C2=A0 =C2=A0 KIAS 16= 0 peaking at 168 (7000) before ending at 166> > We probably haven=E2=80=99t= allowed enough time between changes for full settling of the numbers, but = the trends seem consistent.> > Not sure I agree with your thoughts re engin= e rpm rising and drag constant or rising =3D power must be increasing.> Tor= que x RPM =3D Power> RPM is increasing, but if torque is decreasing faster = than rpm is rising, power will be decreasing.> > What I was interested in d= iscovering was the max power RPM.> My logic is, even if power is constant a= fter 6750rpm (ie. rpm increasing matches torque decreasing) there is no val= ue in spinning her above that rpm.> > What science could I do to discover t= his?> Rightly or wrongly, thats why I value this list, I was looking for th= e peek in Fuel Flow AND IAS (I=E2=80=99m relying on the wideband O2 being a= ccurate and keeping mixture constant)> Its not anything like dramatic, but = I think I can maybe see evidence of that best power (torque peek) RPM being= somewhere around the 6750rpm setting.> We had been spinning her up 600+RPM= higher, perhaps for no advantage.> > On another note about the Intake mani= fold. We shortened the OEM unit to lift peak torque from Mazda's 5000rpm do= cumented curve, hoping for something in the low 6000=E2=80=99s.> We also ke= pt the VDI valve that opens at high RPM to provide Mazda=E2=80=99s Renesis = intake shockwave charging, but presently I cant activate the valve in fligh= t.> And to be honest it seems to be producing a pleasing amount of hp at th= at 6750rpm.> > On Takeoff with a mixture at a Lambda of 0.9 / 13.2 AFR she = is burning 17 Gal of our Premium Unleaded fuel using 1 Ounce / Gal of two s= troke oil, whatever hp that equates too.> > Is my logic OK here or am I jus= t dreaming?> > Cheers> > Steve> > > > > > > > > > > > > > > > > > > > > > > > > > > > On 7 Aug 2020, at 10:34 pm, Charlie England ceengland7@gmail.com <= flyrotary@lancaironline.net> wrote:> >> > That's curious. Are you saying th= at fuel flow *decreased* as rpm *increased* above 6750 rpm? And airspeed de= creased, as well? The only way fuel flow should decrease as rpm increases i= s if the load on the engine is going down.> >> > Is the prop running out of= pitch (or ability to absorb the HP) as you get faster? Is the airframe hit= ting a drag wall due to cooling drag (still shouldn't show a reduction in f= uel flow; it just wouldn't go any faster)?> >> > What actual speeds are you= achieving when this is happening?> >> > Refresh my memory; who's prop (wha= t blades) is it?> >> > Do engine temps go up as you get above 6750 rpm?> >>= > Think about the 'airplane as dyno' thing: If rpm continues to go up, and= the drag (our substitute for torque on the engine brake in a real dyno) st= ays the same or increases, then power *must* be increasing, and so must fue= l flow. Simple math; (torque*rpm)/5252. So, was the plane going downhill, o= r was the prop unable to absorb the additional power and decoupling, unload= ing the engine?> >> > Charlie> >> > On Fri, Aug 7, 2020 at 9:01 AM Stephen = Izett stephen.izett@gmail.com wrote:> > Hi Gu= ys.> >> > Today we did some engine data analysis at 9500, 7500, 6000 and 45= 00 feet agl.> > WOT with constant best power mixture of 0.9 Lambda.> > We l= ooked at Fuel Flow and IAS at 5500,5750,6000,6250,6500,6750 & 7000rpm.> > T= he data revealed a very slight peak in both IAS and Fuel Flow at the 6750rp= m point at basically all altitudes.> > I think what this is suggesting is t= hat increasing rpm beyond 6750 is only increasing wear and has no benefit g= iven the current intake/exhaust configuration.> >> > With the current Prop = Fine Pitch Limit, on initial WOT at Takeoff the engine consistently hits 69= 00rpm within ~6 seconds and 7000rpm by liftoff at 70 KIAS.> > It then gener= ally builds to 7400rpm (With no pitch adjustment - We presently don't have = a Constant Speed Controller) before throttling back as we turn downwind.> >= > > I think this would suggest we ought adjust the props fine limit margina= lly so that takeoff WOT yields approx 6700rpm and keeping the rpm as close = to 6750rpm as> > possible when seeking maximum power by manual prop pitch a= djustment.> > A Constant Speed Controller would be nice!> >> > I=E2=80=99m = now thinking we have enough data to tune the Mixture Correction Table of th= e EC2=E2=80=99s computers for climbing at 6750rpm and as Bill suggested cru= ising at 6000rpm.> >> > Next step in tuning in the Glasair Super IIRG will = be playing with the cowl flaps and cooling drag. Presently the flaps are wi= de open and draggy.> > I=E2=80=99m in the process of completing a little bo= x of 5 differential pressure transducers (MPX10DP=E2=80=99s) mounted under = the cowl.> > I worked out that they interface quite nicely without any othe= r circuitry with the Dynon Skyview's surplus EGT inputs via a new Polynomia= l in the sensor config settings.> > So hoping in the next few weeks to asce= rtain how the inlets, diffusers and outlets are functioning or not.> > What= I like about the MPX10 interface with the Skyview EFIS is the simplicity o= f displaying the pressure data inflight while its all logged along with eng= ine and flight data> > for analysis on the ground.> >> > I=E2=80=99ve got 7= more hours of Phase #1 testing.> > So far both aircraft and engine are rea= lly great.> >> > My friend and test pilot Dawie also demonstrated at the en= d of todays flight - a Lazy Eight, a Roll and Wingover.> > I felt sick for = the next 3 hours. I don't think aerobatics will be in my future.> >> > Than= ks for all the help you guys.> >> > Steve Izett> > Perth Western Australia>= > Glasair Super IIRG Renesis 4 port RD1C EC2 EM3> >> >> >> >> >> >> >> >> = > > On 7 Aug 2020, at 2:25 pm, William Jepson wrjjrs@gmail.com wrote:> > >> > > Stephen,> > > The answer to one of your = questions is easy. A fast cruise RPM should be 6000. Mazda did many instrum= ented runs and found that 6000 rpm was a sweet spot where the dynamics bala= nced perfectly. At 6000 there is almost no load on the bearings. The rotary= would run at that RPM indefinitely. If you have more power at higher speed= s you can use that for maximum speed. Those RPMs are eshaft RPMs not propel= ler.> > > Bill> > >> > > On Thu, Aug 6, 2020 at 4:15 PM Stephen Izett steph= en.izett@gmail.com wrote:> > > Hi Guys> > >> = > > Thanks for all the feedback.> > > I think I didn=E2=80=99t explain my o= bjective clearly enough.> > >> > > Some questions:> > > 1. Given I have var= iable pitch, what combination of MAP and RPM should I climb or cruise at? W= ith fixed pitch I dont suppose you think in these terms.> > > So should I b= e Climbings at WOT & 7000rpm OR WOT & 6300rpm Best Power Mixture.> > >> > >= I think Lynn best understood my intention of trying to use the flight as a= dyne - I didn=E2=80=99t realise the complexity of the relationship of mixt= ure and timing at various settings, thanks Lynn.> > > I thought by keeping = WOT and mixture constant I might ascertain a maximum efficiency combination= for MAP/RPM.> > >> > > I=E2=80=99d like a combination for max power. I=E2= =80=99m thinking identified by higher fuel burn and IAS for the climb, and>= > > a max efficiency/ecconomy combination for cruise identified by best mi= les per gallon.> > >> > > I thought our Renesis with our modified OEM (shor= tened) manifold but no variable intake valves etc. would have a distinctive= peak at ~6400-6600rpm.> > >> > > 2. I=E2=80=99m finding tuning the EC2 (ob= jective being EC provides constant mixture across the flight envelope) is d= ependant on the combination I choose to tune it at.> > > Eg. Tune EC2 MCT f= or one MAP/RPM combination, say a cruise of 18=E2=80=9D AND 5000 rpm, then = the EC will not be able to provide a constant mixture if I then choose 18= =E2=80=9D at 6000rpm.> > > My EC2 has Tracy=E2=80=99s 8 table setup but fue= ling requirements given the extra permutations provided by the variable pit= ch prop (climbing that hill - which gear should I use - 3rd 4th or 5th??)> = > > appears to stretch its inherent capabilities. So I want a plan for what= MAP/RPM I will use and then adjust/tune the EC MCT for that combination.> = > >> > > Thanks again guys.> > >> > > Steve Izett> > >> > >> > >=C2=A0 all = is nice if you fly that combination. If I then choose ab> > >> > > > On 7 A= ug 2020, at 6:16 am, lehanover lehanover@aol.com wrote:> > > >> > > > Your thinking is correct. Control full throttle RP= M with load. Then experiment always at that particular RPM until you have w= hatever data point you were after. Everything affects everything so it may = be that (for example) advancing ignition timing at one RPM adds power but a= t another RPM reduces power. A rich mixture at one RPM may increase power b= ut reduce power at another RPM. To recover even similar data on consecutive= days is difficult. The SAE has some charts that produce a multiplier to ac= count for density temperature and so on. Required to compare results day to= day. It takes a long time to collect good data..........> > > >> > > > Lyn= n E. Hanover> > > >> > > >> > > >> > > > https://search.aol.com/aol/image?p= =3Ddyno+sheets+for+stock+rx-7+engines&s_it=3Dimg-ans&v_t=3Dloki-keyword&fr= =3Dloki-keyword&imgurl=3Dhttp%3A%2F%2Fwww.rx7club.com%2Fattachments%2Ftime-= slips-dyno-128%2F346326d1243952257-anyone-have-stock-turbo-ii-dyno-graph-st= ock-s4-t2.jpg#id=3D19&iurl=3Dhttp%3A%2F%2Fwww.rx7club.com%2Fattachments%2Ft= ime-slips-dyno-128%2F346326d1243952257-anyone-have-stock-turbo-ii-dyno-grap= h-stock-s4-t2.jpg&action=3Dclick> > >> > >> > > --> > > Homepage:=C2=A0 htt= p://www.flyrotary.com/> > > Archive and UnSub:=C2=A0 http://mail.lancaironl= ine.net:81/lists/flyrotary/List.html> >> >> > --> > Homepage:=C2=A0 http://= www.flyrotary.com/> > Archive and UnSub:=C2=A0 http://mail.lancaironline.ne= t:81/lists/flyrotary/List.html> > > --> Homepage:=C2=A0 http://www.flyrotar= y.com/> Archive and UnSub:=C2=A0 http://mail.lancaironline.net:81/lists/fly= rotary/List.html --Homepage:=C2=A0 http://www.flyrotary.com/Archive and UnSub:=C2=A0 http://= mail.lancaironline.net:81/lists/flyrotary/List.html ------=_Part_1204266_790105307.1596849100763 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Not your fault.    I am old and easily conf= used.......

After each dyno pass, you compare each number recover= ed near or in the inlet tract wherever your fresh air supply is recovered. = So as to establish the "Weather" or air conditions the engine is "seeing"

These are large printed (size C formats) years back. = It is now probably a spread sheet for very quick calculations. For example = you are looking for some help at the bottom end to help get out of corners = a bit better. You change idle jets closer to best power at 7,500 RPM then a= dd a bit of accelerator pump. I made movies of the gauges for review. In tw= o days of testing (for this one problem) we have many different inlet air t= emps. Many barometric pressures and many humidity readings. So each pass pr= oduces a different raw HP
reading. You look on the SAE chart for the number you= just recovered and follow the column to the SAE correction number temp. or= pressure or humidity and you fill in your home made form with the "NEW" SA= E multiplier.  Since all of the charts start at sea level each SAE mul= tiplier will reduce the raw HP number. But, all of the passes are now in th= e same format as all of the variables are removed. I could get 2 or 3 good = readings using the movies. The throttle is always wide open and the test RP= M is controlled with a water brake load cell.

In most cases your great idea will cost you HP. but e= very so often Jackpot....4 corrected HP.     Modern dynos ha= ve this stuff built into their computers so the numbers you see are already= corrected to sea level. In olden times they were not. Lynn E. Hanover = ;  

In a message dated 8/7/2020 8:29:40 PM Eastern Standard Time, flyrotary@lan= caironline.net writes:

Sorry Lynn. My apologies those figures @ 9500, 7500,6000 a= nd 4500 are altitude. Didn’t click that they could also be read as RP= M. Sorry!

Again thanks for the expertise, those things you mention r= e flow make sense of the anomalies.

Please excuse my ignorance - SAE tables?
Right, so convert those numbers back to sea level. Can you= explain this for me Lynn?

Much appreciated.

Steve

> On 8 Aug 2020, at 8:08 am, lehanover lehanover@aol.com <= = flyrotary@lancaironline.net> wrote:
>
> The impossible is possible................
>
> Along the way to tuning success you will find that a = specific combination of facts may appear and disappear within a few RPM.&nb= sp; Such as induction tube length VS exhaust system harmonics/back pressure= . Every RPM would suggest that a specific tuned intake length would be idea= l. See the Mazda winning 4 rotor and its adjustable length intake runners.&= nbsp; Exhaust back pressure may be high at one RPM and nonexistent at anoth= er. The whole reason for disconnecting the intake and exhaust  in the = Renesis among other things is to get the tuning down to some form of normal= (Meet California UHC). Having no overlap is a giant step in that direction= . The poor exhaust shapes help pollute the incoming charge a bit so as to r= educe combustion temps and pull back Oxides of Nitrogen. I have seen movies= of fuel air flowing backwards in an intake runner.    When you r= ecord what appears to be faulty data do not discard it and then see it agai= n the next day.          When you make a change...= .make it a big one so you can see which way that one took you. Never make m= ore than one change.  Use the SAE tables to take all of the data down = to sea level. Before you compare two data sets.  It is a steep learnin= g curve......but it will come to you.  I had a fabulous Stuska dyno in= my shop for years.
> and a flow bench. I never did learn all I should have= .
>
> Fixed pitch props (In effect) reduce pitch as air spe= ed through the disc increases.  The suggestion that you turned up 9,50= 0 RPM gives me chills. What would the tip speeds be then?
>
> You can get above 10,000 RPM with 13-B rotors but the= y must be very light and you must look inside after every race because the = tend to crack when that light. Note that the Renesis rear main bearing is t= wo different diameters to allow for that standing sign wave that forms in t= he crank.  Nobody uses Fram filters or lets friends turn over 8,000 RP= M
> Lynn E. Hanover
>
> In a message dated 8/7/2020 6:48:47 PM Eastern Standa= rd Time, flyrotary@lancaironline.net writes:
>
> Hi Charlie and all
>
> On the four runs - Speeds were:
> 147 KIAS 21.6” @ 9500 WOT
> 136 KIAS 18.2” @ 7500 (Not WOT)
> 160 KIAS 24.8” @ 6000 WOT
> 165 KIAS 26.2” @ 4500 WOT
>
> Prop hub is Airmaster 3 blade electric with Aerotek B= lades
>
> On looking over the 4500 ft run:
>    As RPM steps up from 5500-7250 (in 250rp= m inc) over 9 mins (OAT 49)
>    Temps gradually build from 172/154 to 19= 8/171 (Oil/Water)
>    Fuel Flow goes from 14.5 peaking at 16.2= (6750) before ending at 15.8
>    KIAS 160 peaking at 168 (7000) before en= ding at 166
>
> We probably haven’t allowed enough time between= changes for full settling of the numbers, but the trends seem consistent.<= /div>
>
> Not sure I agree with your thoughts re engine rpm ris= ing and drag constant or rising =3D power must be increasing.
> Torque x RPM =3D Power
> RPM is increasing, but if torque is decreasing faster= than rpm is rising, power will be decreasing.
>
> What I was interested in discovering was the max powe= r RPM.
> My logic is, even if power is constant after 6750rpm = (ie. rpm increasing matches torque decreasing) there is no value in spinnin= g her above that rpm.
>
> What science could I do to discover this?
> Rightly or wrongly, thats why I value this list, I wa= s looking for the peek in Fuel Flow AND IAS (I’m relying on the wideb= and O2 being accurate and keeping mixture constant)
> Its not anything like dramatic, but I think I can may= be see evidence of that best power (torque peek) RPM being somewhere around= the 6750rpm setting.
> We had been spinning her up 600+RPM higher, perhaps f= or no advantage.
>
> On another note about the Intake manifold. We shorten= ed the OEM unit to lift peak torque from Mazda's 5000rpm documented curve, = hoping for something in the low 6000’s.
> We also kept the VDI valve that opens at high RPM to = provide Mazda’s Renesis intake shockwave charging, but presently I ca= nt activate the valve in flight.
> And to be honest it seems to be producing a pleasing = amount of hp at that 6750rpm.
>
> On Takeoff with a mixture at a Lambda of 0.9 / 13.2 A= FR she is burning 17 Gal of our Premium Unleaded fuel using 1 Ounce / Gal o= f two stroke oil, whatever hp that equates too.
>
> Is my logic OK here or am I just dreaming?
>
> Cheers
>
> Steve
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> > On 7 Aug 2020, at 10:34 pm, Charlie England ceengland7@= gmail.com <flyrotary@lancaironline.net> wrote:
> >
> > That's curious. Are you saying that fuel flow *d= ecreased* as rpm *increased* above 6750 rpm? And airspeed decreased, as wel= l? The only way fuel flow should decrease as rpm increases is if the load o= n the engine is going down.
> >
> > Is the prop running out of pitch (or ability to = absorb the HP) as you get faster? Is the airframe hitting a drag wall due t= o cooling drag (still shouldn't show a reduction in fuel flow; it just woul= dn't go any faster)?
> >
> > What actual speeds are you achieving when this i= s happening?
> >
> > Refresh my memory; who's prop (what blades) is i= t?
> >
> > Do engine temps go up as you get above 6750 rpm?=
> >
> > Think about the 'airplane as dyno' thing: If rpm= continues to go up, and the drag (our substitute for torque on the engine = brake in a real dyno) stays the same or increases, then power *must* be inc= reasing, and so must fuel flow. Simple math; (torque*rpm)/5252. So, was the= plane going downhill, or was the prop unable to absorb the additional powe= r and decoupling, unloading the engine?
> >
> > Charlie
> >
> > On Fri, Aug 7, 2020 at 9:01 AM Stephen Izett stephen= .izett@gmail.com <flyrotary@lancaironline.net> wrote:
> > Hi Guys.
> >
> > Today we did some engine data analysis at 9500, = 7500, 6000 and 4500 feet agl.
> > WOT with constant best power mixture of 0.9 Lamb= da.
> > We looked at Fuel Flow and IAS at 5500,5750,6000= ,6250,6500,6750 & 7000rpm.
> > The data revealed a very slight peak in both IAS= and Fuel Flow at the 6750rpm point at basically all altitudes.
> > I think what this is suggesting is that increasi= ng rpm beyond 6750 is only increasing wear and has no benefit given the cur= rent intake/exhaust configuration.
> >
> > With the current Prop Fine Pitch Limit, on initi= al WOT at Takeoff the engine consistently hits 6900rpm within ~6 seconds an= d 7000rpm by liftoff at 70 KIAS.
> > It then generally builds to 7400rpm (With no pit= ch adjustment - We presently don't have a Constant Speed Controller) before= throttling back as we turn downwind.
> >
> > I think this would suggest we ought adjust the p= rops fine limit marginally so that takeoff WOT yields approx 6700rpm and ke= eping the rpm as close to 6750rpm as
> > possible when seeking maximum power by manual pr= op pitch adjustment.
> > A Constant Speed Controller would be nice!
> >
> > I’m now thinking we have enough data to tu= ne the Mixture Correction Table of the EC2’s computers for climbing a= t 6750rpm and as Bill suggested cruising at 6000rpm.
> >
> > Next step in tuning in the Glasair Super IIRG wi= ll be playing with the cowl flaps and cooling drag. Presently the flaps are= wide open and draggy.
> > I’m in the process of completing a little = box of 5 differential pressure transducers (MPX10DP’s) mounted under = the cowl.
> > I worked out that they interface quite nicely wi= thout any other circuitry with the Dynon Skyview's surplus EGT inputs via a= new Polynomial in the sensor config settings.
> > So hoping in the next few weeks to ascertain how= the inlets, diffusers and outlets are functioning or not.
> > What I like about the MPX10 interface with the S= kyview EFIS is the simplicity of displaying the pressure data inflight whil= e its all logged along with engine and flight data
> > for analysis on the ground.
> >
> > I’ve got 7 more hours of Phase #1 testing.=
> > So far both aircraft and engine are really great= .
> >
> > My friend and test pilot Dawie also demonstrated= at the end of todays flight - a Lazy Eight, a Roll and Wingover.
> > I felt sick for the next 3 hours. I don't think = aerobatics will be in my future.
> >
> > Thanks for all the help you guys.
> >
> > Steve Izett
> > Perth Western Australia
> > Glasair Super IIRG Renesis 4 port RD1C EC2 EM3
> >
> >
> >
> >
> >
> >
> >
> >
> > > On 7 Aug 2020, at 2:25 pm, William Jepson <= a href=3D"mailto:wrjjrs@gmail.com" rel=3D"noopener noreferrer">wrjjrs@gmail= .com <flyrotary@lancaironline.net> wrote:
> > >
> > > Stephen,
> > > The answer to one of your questions is easy= . A fast cruise RPM should be 6000. Mazda did many instrumented runs and fo= und that 6000 rpm was a sweet spot where the dynamics balanced perfectly. A= t 6000 there is almost no load on the bearings. The rotary would run at tha= t RPM indefinitely. If you have more power at higher speeds you can use tha= t for maximum speed. Those RPMs are eshaft RPMs not propeller.
> > > Bill
> > >
> > > On Thu, Aug 6, 2020 at 4:15 PM Stephen Izet= t st= ephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
> > > Hi Guys
> > >
> > > Thanks for all the feedback.
> > > I think I didn’t explain my objective= clearly enough.
> > >
> > > Some questions:
> > > 1. Given I have variable pitch, what combin= ation of MAP and RPM should I climb or cruise at? With fixed pitch I dont s= uppose you think in these terms.
> > > So should I be Climbings at WOT & 7000r= pm OR WOT & 6300rpm Best Power Mixture.
> > >
> > > I think Lynn best understood my intention o= f trying to use the flight as a dyne - I didn’t realise the complexit= y of the relationship of mixture and timing at various settings, thanks Lyn= n.
> > > I thought by keeping WOT and mixture consta= nt I might ascertain a maximum efficiency combination for MAP/RPM.
> > >
> > > I’d like a combination for max power.= I’m thinking identified by higher fuel burn and IAS for the climb, a= nd
> > > a max efficiency/ecconomy combination for c= ruise identified by best miles per gallon.
> > >
> > > I thought our Renesis with our modified OEM= (shortened) manifold but no variable intake valves etc. would have a disti= nctive peak at ~6400-6600rpm.
> > >
> > > 2. I’m finding tuning the EC2 (object= ive being EC provides constant mixture across the flight envelope) is depen= dant on the combination I choose to tune it at.
> > > Eg. Tune EC2 MCT for one MAP/RPM combinatio= n, say a cruise of 18” AND 5000 rpm, then the EC will not be able to = provide a constant mixture if I then choose 18” at 6000rpm.
> > > My EC2 has Tracy’s 8 table setup but = fueling requirements given the extra permutations provided by the variable = pitch prop (climbing that hill - which gear should I use - 3rd 4th or 5th??= )
> > > appears to stretch its inherent capabilitie= s. So I want a plan for what MAP/RPM I will use and then adjust/tune the EC= MCT for that combination.
> > >
> > > Thanks again guys.
> > >
> > > Steve Izett
> > >
> > >
> > >  all is nice if you fly that combinati= on. If I then choose ab
> > >
> > > > On 7 Aug 2020, at 6:16 am, lehanover <= a href=3D"mailto:lehanover@aol.com" rel=3D"noopener noreferrer">lehanover@a= ol.com <flyrotary@lancaironline.net> wrote:
> > > >
> > > > Your thinking is correct. Control full= throttle RPM with load. Then experiment always at that particular RPM unti= l you have whatever data point you were after. Everything affects everythin= g so it may be that (for example) advancing ignition timing at one RPM adds= power but at another RPM reduces power. A rich mixture at one RPM may incr= ease power but reduce power at another RPM. To recover even similar data on= consecutive days is difficult. The SAE has some charts that produce a mult= iplier to account for density temperature and so on. Required to compare re= sults day to day. It takes a long time to collect good data..........
> > > >
> > > > Lynn E. Hanover
> > > >
> > > >
> > > >
> > >
> > >
> > > --
> > > Homepage:  http://www.flyrota= ry.com/
> >
> >
> > --
>
>
> --


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