X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=NYOYKFL4 c=1 sm=1 tr=0 a=6W9DBQtmHVaXJADi8/5GCQ==:117 a=55z/sxGcUIPVrBMYBb4HRw==:17 a=x7bEGLp0ZPQA:10 a=_Z_nqdSeG58A:10 a=sTwFKg_x9MkA:10 a=DAwyPP_o2Byb1YXLmDAA:9 a=Ia-xEzejAAAA:8 a=pGLkceISAAAA:8 a=OQjxcLmFHaR9vdKcmq0A:9 a=Bls7orfdlmr1He0s:21 a=Kq2qcFoInIPqGC_h:21 a=QEXdDO2ut3YA:10 a=yMhMjlubAAAA:8 a=SSmOFEACAAAA:8 a=CKP_GM63xsvno-Tsn0AA:9 a=Nu4bLP3IxGRdBeyJ:21 a=D1Scje-xajxAcRkl:21 a=v53qzGpnFyJezJ_a:21 a=gKO2Hq4RSVkA:10 a=UiCQ7L4-1S4A:10 a=hTZeC7Yk6K0A:10 a=frz4AuCg-hUA:10 a=Urk15JJjZg1Xo0ryW_k8:22 From: " 12348ung@gmail.com" Received: from mail-pj1-f46.google.com ([209.85.216.46] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 223117 for flyrotary@lancaironline.net; Fri, 08 May 2020 18:24:49 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.216.46; envelope-from=12348ung@gmail.com Received: by mail-pj1-f46.google.com with SMTP id t40so4905437pjb.3 for ; Fri, 08 May 2020 15:24:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:references:in-reply-to:subject:date:message-id:mime-version :thread-index:content-language; bh=RM/aKZ+erzwqG6gLbM7rX3k/3Xmol2aLjy2k4DH6bx8=; b=Oa9zy+d/U7j30wWoLRBvAyesqsBpwOJHVtzr2j3SQ5ikOQt7J7Qa2jfptseiZRXtJT oFe+KYe3zy7JV5n4vyJu1vj22sUoFHusSqxcSPWOtt0C6wbm2BtkZ3X0pBXeW/LT7aY3 BwWFxuCAG9uP35GZL8LmX9vo17NH1sOZd2CbyVKD0S8pXCVZtCOm5M1s51jYx0zsvCau Zu5gygsHOCCZ+ad3xA363Ota1s5cHYfxmShq95CTH2dw8NHR3cshzKBGZwqfZgXOAM3E OPlH34ZGF65XCuthYkIuDay92kJdquJrpyWxj9p+s2Vmm0q8brknzKR4o1q84jjbv1Yn O0MA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:references:in-reply-to:subject:date :message-id:mime-version:thread-index:content-language; bh=RM/aKZ+erzwqG6gLbM7rX3k/3Xmol2aLjy2k4DH6bx8=; b=IVPhlpYypoHbXKbByGCJnS6MJwIeUta2ru4goy6jRo3EhPkIXtlzdPPcZNhKLMJA4P HUb3sXdm5gSrQbJQ7ytY9CnZ8QqWvvWsJ3T0QnXZLItp5hYCEtDF+aYbqePcB5gtIahS RQUo8DIPb7STpxTJSvkt9zmmZ6JWYII6lxHU0Tf5c9B2lqFO/1xijT2qDp7l40qdb8bT cUhPIPZ50MZH6B3FgugpookZr1j8ocNpaCqgEIAQUDM7iI70edXlYBhq4s2UIp2jzlC4 tCEJdWpIMoZSiXPNjkqfKyHiaHyFbDt4Cl4NjEDWLg9LOszwB4X3rYa+lQbz50FSY1Js 7Biw== X-Gm-Message-State: AGi0PuZhO0Guqe7VIR4xfMQO2pqJ5GqyzYR+Y5AofHhU+ursiH01Xgiu JSCh4g17JW+OjY7ykJB4xMDdWpLk/N4= X-Google-Smtp-Source: APiQypKH4FLniNibVgwJ85SAhcZ4CmmCcupYQXQ5zjZ9E0cazvbWHj4qLbGdPGmy/fLIPDPQpfcXGA== X-Received: by 2002:a17:902:ea8b:: with SMTP id x11mr4413097plb.205.1588976671560; Fri, 08 May 2020 15:24:31 -0700 (PDT) Return-Path: <12348ung@gmail.com> Received: from UserPC ([103.198.24.78]) by smtp.gmail.com with ESMTPSA id l137sm2886902pfd.107.2020.05.08.15.24.27 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 08 May 2020 15:24:28 -0700 (PDT) To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Turbos Date: Sat, 9 May 2020 08:24:25 +1000 Message-ID: <004701d62587$6fd9b680$4f8d2380$@gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0048_01D625DB.41883780" X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQDacRYuI3QIbIv9CM4iEayso3CCAaqWJ7Nw Content-Language: en-us This is a multipart message in MIME format. ------=_NextPart_000_0048_01D625DB.41883780 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Dave and contributors, Spent yesterday finally = getting specific answers that I should have had 12 months ago. The guru = that I sent the stock turbo to in the end had no idea as to an upgrade = for temp in the hot section. The up grade that Dave suggested is = approx. $900 USD. Real problem at the moment is the exchange rate with = all the bank charges, the great Ozzie dollar is approx. half. Then = freight---- I see freight on a turbo from the US at up to $800 Oz = dollars!! Then internal freight in OZ, plus labour costs --- I will = have to sell 2 kidneys! Then considering I do not have a stock RX7 manifold to = bolt the turbo to =E2=80=93 I am manufacturing an adaption of the stock = Renesis manifold, so whatever turbo I get it means work to make it fit = and I am =C2=BE down that path. So having already having a = =E2=80=9Cdummy spit=E2=80=9D due to 12 months lost, I lauch out to find = a new turbo in OZ. I find that Garret and others have a hot section = wheel that will stand 1050 degrees C!! Wow that fixes anything that the = rotary puts out with no phone calls involved trying to explain. Once = again I make the usual; mistake telling the company with all these shiny = new turbos that I want it for a drone!! Thought that would by pass the = usual arguments---- silly boy, NO they do not supply for aeronautical = applications!! So I am back to =E2=80=9Cdune buggy=E2=80=9D even though = the nearest beach is 300 miles away. Seems the turbo I require is the = smallest they make. Price is yet to enter the discussion. Will update as I get abused. I am asked continually for = Make, Model, Vin Number, year of manufacturer! All I want is a turbo! Thanks to all, Neil. =20 From: Rotary motors in aircraft =20 Sent: Friday, May 8, 2020 11:17 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Turbos =20 Hi Neil, It all depends on how you size and operate your turbo. In general, the pressure relief, or pop-off valve is not needed in = aircraft. Those come more into play during the fast throttle closures = that occur in highly boosted race cars during shifting. They spend = almost all of their time closed. These valves are not intended to be = the primary pressure regulation and would not function well in such a = capacity. They only limit peak pressure but do not do so with a high = level of accuracy or control ability. They would also be highly = inefficient if used in this manner, as the turbo would be producing = continuously higher back pressure than needed. The turbo would be short = lived and your fuel consumption would suffer greatly. =20 The wastegate issue is a much bigger question but the short answer is = that yes, you probably want/need one. The only exception might be a = large turbine turbo that is sized so big that the max boost was only = achieved at WOT operating conditions. Even then, you would be limiting = the usefulness of your turbo at altitude because if it were sized for = WOT at sea level, it would not be very useful at altitude. If sized for = WOT at altitude you could use throttle to control boost down low, but = you always run the risk of overboost. Similarly, a fixed exhaust bypass = would allow a smaller turbo to be used in the same manner but with less = efficiency and shorter life. I have experimented with my turbo in this = configuration. By removing the flapper valve from my wastegate and = creating a fixed bypass I was able to run at WOT and have approximately = the boost I wanted, but only at a very specific altitude. Any higher = and boost drops off precepitously. Any lower and throttle is needed to = control boost. There is not much of a sweet spot as the natural = variations in conditions created a oscillating situation that is simply = not tolerable. But for maximum benefit from your turbo, longest life = and efficiency there is no substitute for a wastegate of some sort. =20 Dave Leonard N4VY, Turbo Rotary RV-6 =20 On Thu, May 7, 2020 at 2:47 PM 12348ung@gmail.com = > wrote: Can anyone help me with the following? With a turbo, can I just use a = pressure relief valve and negate the wastegate totally?? Looking for = simplicity and weight saving. Neil. ------=_NextPart_000_0048_01D625DB.41883780 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Dave and contributors,

=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Spent yesterday finally = getting specific answers that I should have had 12 months ago.=C2=A0 The = guru that I sent the stock turbo to in the end had no idea as to an = upgrade for temp in the hot section.=C2=A0 The up grade that Dave = suggested is approx. $900 USD.=C2=A0 Real problem at the moment is the = exchange rate with all the bank charges,=C2=A0 the great Ozzie dollar is = approx. half.=C2=A0 Then freight----=C2=A0 I see freight on a turbo from = the US at up to $800 Oz dollars!!=C2=A0=C2=A0 Then internal freight in = OZ, plus labour costs=C2=A0 ---=C2=A0 I will have to sell 2 = kidneys!

=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Then considering I do not have a stock = RX7 manifold to bolt the turbo to =E2=80=93 I am manufacturing an = adaption of the stock Renesis =C2=A0manifold, so whatever turbo I get it = means work to make it fit and I am =C2=BE down that path.=C2=A0 So = having already having a =E2=80=9Cdummy spit=E2=80=9D due to 12 months = lost, I lauch out to find a new turbo in OZ. =C2=A0I find that Garret = and others have a hot section wheel that will stand 1050 degrees = C!!=C2=A0 Wow that fixes anything that the rotary puts out with no phone = calls involved trying to explain.=C2=A0=C2=A0=C2=A0 Once again I make = the usual; mistake telling the company with all these shiny new turbos = that I want it for a drone!!=C2=A0 Thought that would by pass the usual = arguments---- silly boy, NO they do not supply for aeronautical = applications!!=C2=A0 So I am back to =E2=80=9Cdune buggy=E2=80=9D even = though the nearest beach is 300 miles away.=C2=A0 Seems the turbo I = require is the smallest they make.=C2=A0 Price is yet to enter the = discussion.

=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Will update as I get abused.=C2=A0 I am = asked continually for Make, Model, Vin Number, year of = manufacturer!=C2=A0 All I want is a turbo!

Thanks to = all,

Neil.

 

From: Rotary motors in aircraft = <flyrotary@lancaironline.net>
Sent: Friday, May 8, 2020 = 11:17 PM
To: Rotary motors in aircraft = <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: = Turbos

 

Hi = Neil,

It all depends on how you = size and operate your turbo.

In = general, the pressure relief, or pop-off valve is not needed in = aircraft.  Those come more into play during the fast throttle = closures that occur in highly boosted race cars during shifting.  = They spend almost all of their time closed.  These valves are not = intended to be the primary pressure regulation and would not function = well in such a capacity. They only limit peak pressure but do not do so = with a high level of accuracy or control ability.  They would also = be highly inefficient if used in this manner, as the turbo would be = producing continuously higher back pressure than needed.  The = turbo would be short lived and your fuel consumption would suffer = greatly.

 

The wastegate issue is a much bigger question but the = short answer is that yes, you probably want/need one.  The only = exception might be a large turbine turbo that is sized so big that the = max boost was only achieved at WOT operating conditions.  Even = then, you would be limiting the usefulness of your turbo at altitude = because if it were sized for WOT at sea level, it would not be very = useful at altitude.  If sized for WOT at altitude you could use = throttle to control boost down low, but you always run the risk of = overboost.  Similarly, a fixed exhaust bypass would allow a smaller = turbo to be used in the same manner but with less efficiency and shorter = life.  I have experimented with my turbo in this = configuration.  By removing the flapper valve from my wastegate and = creating a fixed bypass I was able to run at WOT and have approximately = the boost I wanted, but only at a very specific altitude.  Any = higher and boost drops off precepitously.  Any lower and throttle = is needed to control boost.  There is not much of a sweet spot as = the natural variations in conditions created a = oscillating situation that is simply not tolerable.  But for = maximum benefit from your turbo, longest life and efficiency there is no = substitute for a wastegate of some sort.

 

Dave Leonard

N4VY, Turbo Rotary RV-6

 

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