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root писал(а):

любитель Фордов писал(а): А теперь ответь, что будет с лагом?

Если ставить две одинаковые турбины параллельно, то ничего не изменится.

любитель Фордов писал(а):Что я думаю дело десятое, а вот твой ответ говорит о непонимании принципа работы турбины. И про мат часть я не шучу.

root писал(а):

любитель Фордов писал(а):Что я думаю дело десятое, а вот твой ответ говорит о непонимании принципа работы турбины. И про мат часть я не шучу.

И понимать нечего... выхлоп крутит крыльчатку... крыльчатка валом соединена с другой крыльчаткой, которая качает воздух...
На рабочие обороты (70000-200000) турба выходит при 3000-8000 об. двигателя...
Перепускник (в моем случае встроенный) сбрасывает давление, когда воздуха закачивается слишком много...

Компрессор работает от ременного привода... Поэтому "турбояма" отсутствует, дует пропорционально с оборотами двигла...

Тема создана для того, чтобы понять как наддуть доп.воздуха пока турбина не вышла на рабочие обороты...

root писал(а):

любитель Фордов писал(а):Что я думаю дело десятое, а вот твой ответ говорит о непонимании принципа работы турбины. И про мат часть я не шучу.

И понимать нечего... выхлоп крутит крыльчатку... крыльчатка валом соединена с другой крыльчаткой, которая качает воздух...
На рабочие обороты (70000-200000) турба выходит при 3000-8000 об. двигателя...
Перепускник (в моем случае встроенный) сбрасывает давление, когда воздуха закачивается слишком много...

Компрессор работает от ременного привода... Поэтому "турбояма" отсутствует, дует пропорционально с оборотами двигла...

Тема создана для того, чтобы понять как наддуть доп.воздуха пока турбина не вышла на рабочие обороты...

Moonraker писал(а):

root писал(а): (Турбина)И понимать нечего... выхлоп крутит крыльчатку... крыльчатка валом соединена с другой крыльчаткой, которая качает воздух...
...
(Нагнетатель)Компрессор работает от ременного привода... Поэтому "турбояма" отсутствует, дует пропорционально с оборотами двигла...
...

Не обижайся, но матчасть все-таки надо подучить...
"пропорционально с оборотами двигла" дует как раз компрессор, так как ЖЕСТКО связан механической связью с коленвалом. А турбина дует пропорционально МГНОВЕННОЙ МАССЕ выхлопных газов. и рабочий диапазон зависит от характеристик конкретной турбины - есть и такие, что работают на 1000 об/мин...

root писал(а):Компрессор работает от ременного привода... Поэтому "турбояма" отсутствует, дует пропорционально с оборотами двигла...

Moonraker писал(а):о какой путанице в терминах ты говоришь? или вот это

root писал(а):Компрессор работает от ременного привода... Поэтому "турбояма" отсутствует, дует пропорционально с оборотами двигла...

ты писал про турбочарджер?

root писал(а):

Moonraker писал(а):о какой путанице в терминах ты говоришь? или вот это

root писал(а):Компрессор работает от ременного привода... Поэтому "турбояма" отсутствует, дует пропорционально с оборотами двигла...

ты писал про турбочарджер?

Про суперчарджер...
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Ключевой вопрос сможет ли ТЧ выкачать достаточно воздуха из СЧ на повышенных оборотах? Или нужно дополнительный подсос воздуха делать (между СЧ и ТЧ)? И как его делать...

Moonraker писал(а): Но для начала почитай книжки на тему forced induction. Иначе это будет строительство вавилонской башни.

The Concept of Forced Induction
One of the primary factors affecting engine performance as the ability to get as much of the air and fuel mixture into the engine as possible. It can be thought of as the engines ability to "inhale". In order to produce power, an engine requires a fuel and air mixture to be mixed together and then brought into the cycle. The concept of forced induction is essentially a method wherein we literally compress the air before we bring it into the process of combustion. So basically, think of an engine as a person who is gasping for air after a long run down the street. This person is gasping because they are trying to circulate as much air as possible through their lungs. Now imagine if you were able to force more air into their lungs then they would otherwise be able to suck in on their own. This would in turn help them out very much. In fact, it would help them so much that they would probably be able to run for allot longer without having to stop in order to "catch their breath". In turn, this would yield greater performance. So basically, you can pretty much parallel this idea to an engine. The more air you get into it, the more performance you'll get out of it. This is where the concept of forced induction was derived. While different systems have been designed to achieve the same result (e.g. Superchargers and Turbo Units) the Turbo unit seems to have dominated. In brief, the two systems differ from one another in the means by which the compression process is powered. The turbo unit works by making use of exhaust gases in order to compress the intake while the supercharger mechanically translates the engines rotational power in order to do the same job.

Moonraker писал(а):эт ты для меня перевел? спасибо, но у меня с этим языком проблем нет. и книжки я давно купил и прочитал.....

Sequential Twin-Turbo
Sequential Twin-Turbo refers to a set up in which the motor can utilize only one turbocharger for lower engine speeds, and both turbochargers at higher engine speeds. During low to mid engine speeds, when available spent exhaust energy is minimal, only one turbocharger (the primary turbocharger) is active. During this period, all of the engine's exhaust energy is directed to the primary turbocharger only, lowering the boost threshold, and increasing power output at low engine speeds. Towards the end of this cycle, the secondary turbocharger is partially activated (both compressor and turbine flow) in order to pre-spool the secondary turbocharger prior to its full utilization. Once a preset engine speed or boost pressure is attained, valves controlling compressor and turbine flow through the secondary turbocharger are opened completely. At this point the engine is functioning in a full twin-turbocharger form, providing maximum power output. Sequential twin-turbocharger systems provide a way to decrease turbo lag without compromising ultimate boost output and engine power. Examples of cars with a sequential twin-turbo setup include the actual Volkswagen Golf (Rabbit) MK5 GT 1993-2002 Toyota Supra Turbo (JZA8x), the 1992-2002 Mazda RX-7 Turbo (FD3S), and the 1986-1988 Porsche 959. With recent advancements in turbocharger design, sequential twin turbo systems have fallen out of favor because they are seen as unnecessarily costly and complex.

Sequential twin-turbos are usually much more complicated than a single or parallel twin-turbo systems because they require what amounts to three sets of pipes-intake and wastegate pipes for the two turbochargers as well as valves to control the direction of the exhaust gases. An example of this is the current BMW E60 5-Series 535d. Another well-known example is the 1993-2002 Mazda RX-7. Many new diesel engines use this technology to not only eliminate lag but also to reduce fuel consumption and produce cleaner emissions.

How Supra Sequential Twin Turbo Work

Article by John Cribb

The main principle of this system is to be able to route engine exhaust through one or both turbo(s) in the most efficient manner possible, in order to achieve useful boost at both low and high loads.

At low engine RPM and load, all engine exhaust is routed through the #1 turbine in order to have boost at low rpms; this is called single mode. As engine load and RPM increase, the system will bring the #2 turbo online in a controlled manner, so there is no shock to the turbo or the engine, nor (in theory) any spikes or flat spots in the engine torque curve. This is known as the transition mode. Finally when both turbo’s are online and boosting in parallel, this is called true twin turbo mode.

There are 4 sets of VSV's (Vacuum Solenoid Valve), actuators, and control valves for the STTS. Each VSV allows stored air from a small accumulator (pressure tank) to pass to, or bleed from the actuators. Each of the 4 control valves has an air operated actuator, and an ECU controlled VSV. Two of the control valves, the EGCV and IACV, have only two positions, either open or shut as their VSV’s are controlled by On/Off signals from the ECU, while the other two, the EBV and WG, can be controlled to any position between 0 and 100%, as their VSV’s are operated by PWM duty cycle signals from the ECU.

Following is a definition and description for each control valve:
Wastegate (WG):
This normally closed valve is located in a “Tee” of the engine exhaust, before the turbocharger turbines. When the WG is closed, all engine exhaust must pass through the turbo(s) to exit. When the WG is open, some exhaust can “escape” before the turbo(s) and will exit directly into the downpipe, cat’s, etc. There is a control line connected directly from the turbochargers’ compressor discharge to the WG actuator, so whatever boost pressure is being made by the turbo(s) will be sent to the WG actuator. As boost pressure rises, so will the pressure in this line, which causes the WG to open. As exhaust energy “escapes” by the opening of the WG, the turbo’s will slow down, and boost pressure will fall, which will cause the control line pressure to fall, and the WG to begin closing. By this inverse proportional action, the WG can control boost mechanically.
Mounted in the control line between the turbo’s and the WG, is the WG VSV. When this VSV is duty cycled by the ECU, it acts as a “bleeder” and reduces the pressure in the control line, which keeps the WG closed longer. The higher the duty cycle of the WG VSV, the more delayed the opening of the WG and the higher the boost. If the WG VSV should fail, it will close and the WG will receive full manifold pressure, which will open it much sooner, reducing boost pressure. The configuration of this VSV in “bleeder” mode is also known as a “fail-safe” configuration.
Exhaust gas Bypass Valve (EBV):
This normally closed valve is located downstream of both the #1 and #2 turbines, but before the EGCV. At about 3500 rpm, the ECU “duty cycles” the VSV for this valve causing it to open gradually. Normally, the exhaust from the #2 turbine is blocked by the closed EGCV, so when the EBV opens, there is now a path for a small amount of exhaust gas to flow through the #2 turbine and exit, this allows the #2 turbine to “prespool”. This “prespool” smoothes the transition from 1 to 2 turbos, and cushions the shock of the EGCV opening. The EBV valve is sometimes confused for a wastegate, but it is located after the turbine wheels instead of in front of them, so it is not a 2nd wastegate.

Exhaust Gas Control Valve (EGCV):
This normally closed valve is located in the #2 turbine exhaust discharge piping, and it serves to block the exhaust flow through the #2 turbine. When this valve is closed, all exhaust flow must pass through the #1 turbine. At about 4000 rpm, and after the EBV has opened, the ECU energises the EGCV VSV to open the EGCV. This unblocks the discharge from the #2 turbine so exhaust gas can now flow unrestricted through the #2 turbine and out the exhaust system. This brings the #2 turbo up to full operating speed.
Intake Air Control Valve (IACV):
This normally closed valve is located in the intake system, just after the #2 compressor discharge. When this valve is in the closed position, boost is blocked from the #2 compressor, but more importantly, no backflow from #1 is possible which might cause #2 to spin backwards. Just after the EGCV is opened, the ECU energises the IACV VSV to open the IACV. This allows the full boost pressure from #2 compressor to join with boost coming from #1 compressor and the system is now operating in true twin turbo mode.

There is also a mechanical 1 way reed valve within the same housing of the IACV, and in parallel with it, which allows boost from #2 to enter the common manifold if its pressure is equal to, or greater than the #1 boost during prespool and the initial opening of the EGCV.

Here is the sequence of events from single to true twin turbo operation.
1. At idle the WG, EBV, EGCV and IACV valves are all closed.
2. From 1500 to 3500 RPM, and low loads, the above valves remain closed, and the system operates only on the #1 turbocharger.  (Single mode)
3. Around 3500 RPM, the ECU will duty cycle the EBV open, and allow the #2 turbocharger to prespool. If/when #2’s boost pressure is high enough, the mechanical reed valve will open, allowing #2 boost to join #1 boost in the common system. (Transition mode).
4. As RPM’s and load increase, the EGCV will open, allowing more flow of exhaust gas from the #2 turbine. At about the same time, the IACV will also open, allowing the #2 compressor to flow into the intake system. Once the EGCV and IACV are both open, the two turbochargers are operating in True Twin mode, with (in theory again) equal exhaust and intake flows.
Boost pressure of the overall system is always controlled by the duty cycled VSV for the WG

Moonraker писал(а):
из displacement-type нет, не сможет. у них после определененных оборотов наступает потолок по пропускной способности. высосать из них сверх того не получится в силу физического устройства (если сосать из мясорубки фарш, он быстрее не полезет). из центробежных - может быть, у них производительность растет линейно с оборотами. но тогда нах еще и турбина нужна?